creating extension including dependencies

From 5b39557fec93ebf02bcba73cf54da05e00342bdf Mon Sep 17 00:00:00 2001
From: Petr Jelinek <pjmodos@pjmodos.net>
Date: Sat, 13 Jun 2015 19:49:10 +0200
Subject: [PATCH] CREATE EXTENSION CASCADE

---
 contrib/hstore_plperl/expected/hstore_plperl.out   |   6 +-
 contrib/hstore_plperl/expected/hstore_plperlu.out  |   6 +-
 contrib/hstore_plperl/sql/hstore_plperl.sql        |   4 +-
 contrib/hstore_plperl/sql/hstore_plperlu.sql       |   4 +-
 .../hstore_plpython/expected/hstore_plpython.out   |   4 +-
 contrib/hstore_plpython/sql/hstore_plpython.sql    |   3 +-
 contrib/ltree_plpython/expected/ltree_plpython.out |   4 +-
 contrib/ltree_plpython/sql/ltree_plpython.sql      |   3 +-
 doc/src/sgml/ref/create_extension.sgml             |  22 ++++-
 src/backend/commands/extension.c                   | 101 ++++++++++++++++++++-
 src/backend/parser/gram.y                          |   8 ++
 src/test/modules/Makefile                          |   1 +
 src/test/modules/test_extensions/.gitignore        |   3 +
 src/test/modules/test_extensions/Makefile          |  22 +++++
 .../test_extensions/expected/test_extensions.out   |  24 +++++
 .../test_extensions/sql/test_extensions.sql        |  15 +++
 .../modules/test_extensions/test_ext1--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext1.control |   4 +
 .../modules/test_extensions/test_ext2--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext2.control |   4 +
 .../modules/test_extensions/test_ext3--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext3.control |   3 +
 .../test_extensions/test_ext_cyclic1--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic1.control       |   4 +
 .../test_extensions/test_ext_cyclic2--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic2.control       |   4 +
 src/tools/msvc/Mkvcbuild.pm                        |   2 +-
 27 files changed, 239 insertions(+), 27 deletions(-)
 create mode 100644 src/test/modules/test_extensions/.gitignore
 create mode 100644 src/test/modules/test_extensions/Makefile
 create mode 100644 src/test/modules/test_extensions/expected/test_extensions.out
 create mode 100644 src/test/modules/test_extensions/sql/test_extensions.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1.control
 create mode 100644 src/test/modules/test_extensions/test_ext2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext2.control
 create mode 100644 src/test/modules/test_extensions/test_ext3--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext3.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2.control

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index cf384eb..25fc506 100644
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperl"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/expected/hstore_plperlu.out b/contrib/hstore_plperl/expected/hstore_plperlu.out
index 8c689ad..3fc3201 100644
--- a/contrib/hstore_plperl/expected/hstore_plperlu.out
+++ b/contrib/hstore_plperl/expected/hstore_plperlu.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperlu"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 0f70f14..9398aed 100644
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plperl/sql/hstore_plperlu.sql b/contrib/hstore_plperl/sql/hstore_plperlu.sql
index 3cfb2fd..8d8508c 100644
--- a/contrib/hstore_plperl/sql/hstore_plperlu.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperlu.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index b7a6a92..55f4efe 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 -- test hstore -> python
 CREATE FUNCTION test1(val hstore) RETURNS int
 LANGUAGE plpythonu
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index 9ff2ebc..d55beda 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
 
 
 -- test hstore -> python
diff --git a/contrib/ltree_plpython/expected/ltree_plpython.out b/contrib/ltree_plpython/expected/ltree_plpython.out
index 934529e..9bee6be 100644
--- a/contrib/ltree_plpython/expected/ltree_plpython.out
+++ b/contrib/ltree_plpython/expected/ltree_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 CREATE FUNCTION test1(val ltree) RETURNS int
 LANGUAGE plpythonu
 TRANSFORM FOR TYPE ltree
diff --git a/contrib/ltree_plpython/sql/ltree_plpython.sql b/contrib/ltree_plpython/sql/ltree_plpython.sql
index f08ff6a..210f542 100644
--- a/contrib/ltree_plpython/sql/ltree_plpython.sql
+++ b/contrib/ltree_plpython/sql/ltree_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
 
 
 CREATE FUNCTION test1(val ltree) RETURNS int
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index a1e7e4f8..3d63c3e 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -22,9 +22,10 @@ PostgreSQL documentation
  <refsynopsisdiv>
 <synopsis>
 CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name</replaceable>
-    [ WITH ] [ SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
+    [ WITH ] [ [ DEFAULT ] SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
              [ VERSION <replaceable class="parameter">version</replaceable> ]
              [ FROM <replaceable class="parameter">old_version</replaceable> ]
+             [ CASCADE ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -95,6 +96,14 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         schema either, the current default object creation schema is used.
        </para>
        <para>
+        In case the extension specifies schema in its control file, the schema
+        can't be overriden using <literal>SCHEMA</> clause. If the optional
+        <literal>DEFAULT</> parameter is specified, the
+        <replaceable class="parameter">schema_name</replaceable> will only be
+        used for extensions which do not specify their schema in their control
+        file.
+       </para>
+       <para>
         Remember that the extension itself is not considered to be within any
         schema: extensions have unqualified names that must be unique
         database-wide.  But objects belonging to the extension can be within
@@ -139,6 +148,17 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry>
+      <term><literal>CASCADE</></term>
+      <listitem>
+       <para>
+        Try to install extension including the required dependencies
+        recursively. The <literal>DEFAULT SCHEMA</> option will be propagated
+        to the required extensions.
+       </para>
+      </listitem>
+     </varlistentry>
   </variablelist>
  </refsect1>
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 2b1dcd0..96de79e 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -48,6 +48,7 @@
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "storage/fd.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -1173,10 +1174,14 @@ CreateExtension(CreateExtensionStmt *stmt)
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
 	DefElem    *d_old_version = NULL;
+	DefElem	   *d_cascade = NULL;
+	DefElem    *d_default_schema = NULL;
 	char	   *schemaName;
 	Oid			schemaOid;
 	char	   *versionName;
 	char	   *oldVersionName;
+	bool		cascade = false;
+	List	   *cascade_parents = NIL;
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
@@ -1238,7 +1243,7 @@ CreateExtension(CreateExtensionStmt *stmt)
 
 		if (strcmp(defel->defname, "schema") == 0)
 		{
-			if (d_schema)
+			if (d_schema || d_default_schema)
 				ereport(ERROR,
 						(errcode(ERRCODE_SYNTAX_ERROR),
 						 errmsg("conflicting or redundant options")));
@@ -1260,6 +1265,22 @@ CreateExtension(CreateExtensionStmt *stmt)
 						 errmsg("conflicting or redundant options")));
 			d_old_version = defel;
 		}
+		else if (strcmp(defel->defname, "cascade") == 0)
+		{
+			if (d_cascade)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_cascade = defel;
+		}
+		else if (strcmp(defel->defname, "default_schema") == 0)
+		{
+			if (d_default_schema || d_schema)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_default_schema = defel;
+		}
 		else
 			elog(ERROR, "unrecognized option: %s", defel->defname);
 	}
@@ -1380,6 +1401,19 @@ CreateExtension(CreateExtensionStmt *stmt)
 			schemaOid = get_namespace_oid(schemaName, false);
 		}
 	}
+	else if (d_default_schema && d_default_schema->arg)
+	{
+		/*
+		 * User given default schema,
+		 * CREATE EXTENSION ... WITH DEFAULT SCHEMA ...
+		 *
+		 * It only affects relocatable extensions.
+		 */
+		schemaName = strVal(d_default_schema->arg);
+
+		/* If the user is giving us the schema name, it must exist already */
+		schemaOid = get_namespace_oid(schemaName, false);
+	}
 	else
 	{
 		/*
@@ -1402,6 +1436,15 @@ CreateExtension(CreateExtensionStmt *stmt)
 		list_free(search_path);
 	}
 
+	/* Handle the CASCADE option. */
+	if (d_cascade)
+	{
+		cascade = true;
+		if (d_cascade->arg)
+			cascade_parents = (List *) d_cascade->arg;
+	}
+
+
 	/*
 	 * We don't check creation rights on the target namespace here.  If the
 	 * extension script actually creates any objects there, it will fail if
@@ -1429,10 +1472,58 @@ CreateExtension(CreateExtensionStmt *stmt)
 		 */
 		reqext = get_extension_oid(curreq, true);
 		if (!OidIsValid(reqext))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("required extension \"%s\" is not installed",
-							curreq)));
+		{
+			if (cascade)
+			{
+				CreateExtensionStmt *ces;
+				ListCell   *lc;
+
+				ereport(NOTICE,
+						(errmsg("installing required extension \"%s\"",
+								curreq)));
+
+				/* Check for cyclic dependency between extension. */
+				foreach(lc, cascade_parents)
+				{
+					char	   *pname = (char *) lfirst(lc);
+
+					if (strcmp(pname, curreq) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_RECURSION),
+								 errmsg("cyclic dependency detected between extensions \"%s\" and \"%s\"",
+										curreq, stmt->extname)));
+				}
+
+				/* Create and execute new CREATE EXTENSION statement. */
+				ces = makeNode(CreateExtensionStmt);
+				ces->extname = curreq;
+				ces->if_not_exists = false;
+
+				/*
+				 * Propagate the CASCADE option and add current extenssion
+				 * to the list for checking the cyclic dependencies.
+				 */
+				cascade_parents = lappend(cascade_parents, stmt->extname);
+				ces->options = list_make1(makeDefElem("cascade",
+													  (Node *) cascade_parents));
+
+				/* Propagate the DEFAULT SCHEMA option if given. */
+				if (d_default_schema && d_default_schema->arg)
+					ces->options = lappend(ces->options, d_default_schema);
+
+				CreateExtension(ces);
+
+				/* We leak the DeflElems but probably not worth worrying about */
+				list_free(ces->options);
+				pfree(ces);
+			}
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("required extension \"%s\" is not installed",
+								curreq)));
+		}
+
 		reqschema = get_extension_schema(reqext);
 		requiredExtensions = lappend_oid(requiredExtensions, reqext);
 		requiredSchemas = lappend_oid(requiredSchemas, reqschema);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2b02a2e..9da4b7d 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3849,6 +3849,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("schema", (Node *)makeString($2));
 				}
+			| DEFAULT SCHEMA name
+				{
+					$$ = makeDefElem("default_schema", (Node *)makeString($3));
+				}
 			| VERSION_P NonReservedWord_or_Sconst
 				{
 					$$ = makeDefElem("new_version", (Node *)makeString($2));
@@ -3857,6 +3861,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("old_version", (Node *)makeString($2));
 				}
+			| CASCADE
+				{
+					$$ = makeDefElem("cascade", NULL);
+				}
 		;
 
 /*****************************************************************************
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 8213e23..84b4423 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -8,6 +8,7 @@ SUBDIRS = \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \
+		  test_extensions \
 		  test_parser \
 		  test_rls_hooks \
 		  test_shm_mq \
diff --git a/src/test/modules/test_extensions/.gitignore b/src/test/modules/test_extensions/.gitignore
new file mode 100644
index 0000000..c08326f
--- /dev/null
+++ b/src/test/modules/test_extensions/.gitignore
@@ -0,0 +1,3 @@
+# Generated subdirectories
+/results/
+/tmp_check/
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
new file mode 100644
index 0000000..32f6aab
--- /dev/null
+++ b/src/test/modules/test_extensions/Makefile
@@ -0,0 +1,22 @@
+# src/test/modules/test_extensions/Makefile
+
+MODULE = test_extensions
+PGFILEDESC = "test_extensions - regression testing for EXTENSION support"
+
+EXTENSION = test_ext1 test_ext2 test_ext3 test_ext_cyclic1 test_ext_cyclic2
+DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
+	   test_ext_cyclic1--1.0.sql test_ext_cyclic2--1.0.sql
+
+# test_ddl_deparse must be first
+REGRESS = test_extensions
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_extensions
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
new file mode 100644
index 0000000..f4a5ba1
--- /dev/null
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -0,0 +1,24 @@
+CREATE EXTENSION test_ext1;
+ERROR:  required extension "test_ext2" is not installed
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 CASCADE SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+CREATE EXTENSION test_ext1 CASCADE DEFAULT SCHEMA test_ext;
+NOTICE:  installing required extension "test_ext2"
+NOTICE:  installing required extension "test_ext3"
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+  extname  |  nspname  | extversion | extrelocatable 
+-----------+-----------+------------+----------------
+ test_ext2 | test_ext  | 1.0        | t
+ test_ext3 | test_ext  | 1.0        | t
+ test_ext1 | test_ext1 | 1.0        | f
+(3 rows)
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+NOTICE:  installing required extension "test_ext_cyclic2"
+NOTICE:  installing required extension "test_ext_cyclic1"
+ERROR:  cyclic dependency detected between extensions "test_ext_cyclic1" and "test_ext_cyclic2"
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
new file mode 100644
index 0000000..23a1991
--- /dev/null
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -0,0 +1,15 @@
+CREATE EXTENSION test_ext1;
+
+CREATE SCHEMA test_ext;
+
+CREATE EXTENSION test_ext1 CASCADE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 CASCADE DEFAULT SCHEMA test_ext;
+
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/test_ext1--1.0.sql b/src/test/modules/test_extensions/test_ext1--1.0.sql
new file mode 100644
index 0000000..9a4bb1b
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext1.control b/src/test/modules/test_extensions/test_ext1.control
new file mode 100644
index 0000000..c7ef323
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 1'
+default_version = '1.0'
+schema = 'test_ext1'
+requires = 'test_ext2'
diff --git a/src/test/modules/test_extensions/test_ext2--1.0.sql b/src/test/modules/test_extensions/test_ext2--1.0.sql
new file mode 100644
index 0000000..0f6d4ec
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext2.control b/src/test/modules/test_extensions/test_ext2.control
new file mode 100644
index 0000000..788337e
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext3'
diff --git a/src/test/modules/test_extensions/test_ext3--1.0.sql b/src/test/modules/test_extensions/test_ext3--1.0.sql
new file mode 100644
index 0000000..7dec684
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext3--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext3" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext3.control b/src/test/modules/test_extensions/test_ext3.control
new file mode 100644
index 0000000..5f1afe7
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 3'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
new file mode 100644
index 0000000..81bdaf4
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1.control b/src/test/modules/test_extensions/test_ext_cyclic1.control
new file mode 100644
index 0000000..aaab403
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 1'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic2'
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
new file mode 100644
index 0000000..ae2b3e9
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2.control b/src/test/modules/test_extensions/test_ext_cyclic2.control
new file mode 100644
index 0000000..1e28f96
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic1'
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index d70db40..9b3e31e 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -41,7 +41,7 @@ my $contrib_extrasource = {
 	'seg'  => [ 'contrib/seg/segscan.l',   'contrib/seg/segparse.y' ], };
 my @contrib_excludes = (
 	'commit_ts',      'hstore_plperl', 'hstore_plpython', 'intagg',
-	'ltree_plpython', 'pgcrypto',      'sepgsql');
+	'ltree_plpython', 'pgcrypto',      'sepgsql',         'test_extensions');
 
 # Set of variables for frontend modules
 my $frontend_defines = { 'initdb' => 'FRONTEND' };
-- 
1.9.1

From 54529b7e8bf2e5554569369ff976befbac981a25 Mon Sep 17 00:00:00 2001
From: Petr Jelinek <pjmodos@pjmodos.net>
Date: Sat, 13 Jun 2015 19:49:10 +0200
Subject: [PATCH] CREATE EXTENSION CASCADE

---
 contrib/hstore_plperl/expected/hstore_plperl.out   |   6 +-
 contrib/hstore_plperl/expected/hstore_plperlu.out  |   6 +-
 contrib/hstore_plperl/sql/hstore_plperl.sql        |   4 +-
 contrib/hstore_plperl/sql/hstore_plperlu.sql       |   4 +-
 .../hstore_plpython/expected/hstore_plpython.out   |   4 +-
 contrib/hstore_plpython/sql/hstore_plpython.sql    |   3 +-
 contrib/ltree_plpython/expected/ltree_plpython.out |   4 +-
 contrib/ltree_plpython/sql/ltree_plpython.sql      |   3 +-
 doc/src/sgml/ref/create_extension.sgml             |  22 ++++-
 src/backend/commands/extension.c                   | 103 ++++++++++++++++++++-
 src/backend/parser/gram.y                          |   8 ++
 src/bin/psql/tab-complete.c                        |   7 +-
 src/test/modules/Makefile                          |   1 +
 src/test/modules/test_extensions/.gitignore        |   3 +
 src/test/modules/test_extensions/Makefile          |  22 +++++
 .../test_extensions/expected/test_extensions.out   |  24 +++++
 .../test_extensions/sql/test_extensions.sql        |  15 +++
 .../modules/test_extensions/test_ext1--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext1.control |   4 +
 .../modules/test_extensions/test_ext2--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext2.control |   4 +
 .../modules/test_extensions/test_ext3--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext3.control |   3 +
 .../test_extensions/test_ext_cyclic1--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic1.control       |   4 +
 .../test_extensions/test_ext_cyclic2--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic2.control       |   4 +
 src/tools/msvc/Mkvcbuild.pm                        |   2 +-
 28 files changed, 247 insertions(+), 28 deletions(-)
 create mode 100644 src/test/modules/test_extensions/.gitignore
 create mode 100644 src/test/modules/test_extensions/Makefile
 create mode 100644 src/test/modules/test_extensions/expected/test_extensions.out
 create mode 100644 src/test/modules/test_extensions/sql/test_extensions.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1.control
 create mode 100644 src/test/modules/test_extensions/test_ext2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext2.control
 create mode 100644 src/test/modules/test_extensions/test_ext3--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext3.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2.control

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index cf384eb..25fc506 100644
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperl"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/expected/hstore_plperlu.out b/contrib/hstore_plperl/expected/hstore_plperlu.out
index 8c689ad..3fc3201 100644
--- a/contrib/hstore_plperl/expected/hstore_plperlu.out
+++ b/contrib/hstore_plperl/expected/hstore_plperlu.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperlu"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 0f70f14..9398aed 100644
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plperl/sql/hstore_plperlu.sql b/contrib/hstore_plperl/sql/hstore_plperlu.sql
index 3cfb2fd..8d8508c 100644
--- a/contrib/hstore_plperl/sql/hstore_plperlu.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperlu.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index b7a6a92..55f4efe 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 -- test hstore -> python
 CREATE FUNCTION test1(val hstore) RETURNS int
 LANGUAGE plpythonu
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index 9ff2ebc..d55beda 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
 
 
 -- test hstore -> python
diff --git a/contrib/ltree_plpython/expected/ltree_plpython.out b/contrib/ltree_plpython/expected/ltree_plpython.out
index 934529e..9bee6be 100644
--- a/contrib/ltree_plpython/expected/ltree_plpython.out
+++ b/contrib/ltree_plpython/expected/ltree_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 CREATE FUNCTION test1(val ltree) RETURNS int
 LANGUAGE plpythonu
 TRANSFORM FOR TYPE ltree
diff --git a/contrib/ltree_plpython/sql/ltree_plpython.sql b/contrib/ltree_plpython/sql/ltree_plpython.sql
index f08ff6a..210f542 100644
--- a/contrib/ltree_plpython/sql/ltree_plpython.sql
+++ b/contrib/ltree_plpython/sql/ltree_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
 
 
 CREATE FUNCTION test1(val ltree) RETURNS int
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index a1e7e4f8..3d63c3e 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -22,9 +22,10 @@ PostgreSQL documentation
  <refsynopsisdiv>
 <synopsis>
 CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name</replaceable>
-    [ WITH ] [ SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
+    [ WITH ] [ [ DEFAULT ] SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
              [ VERSION <replaceable class="parameter">version</replaceable> ]
              [ FROM <replaceable class="parameter">old_version</replaceable> ]
+             [ CASCADE ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -95,6 +96,14 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         schema either, the current default object creation schema is used.
        </para>
        <para>
+        In case the extension specifies schema in its control file, the schema
+        can't be overriden using <literal>SCHEMA</> clause. If the optional
+        <literal>DEFAULT</> parameter is specified, the
+        <replaceable class="parameter">schema_name</replaceable> will only be
+        used for extensions which do not specify their schema in their control
+        file.
+       </para>
+       <para>
         Remember that the extension itself is not considered to be within any
         schema: extensions have unqualified names that must be unique
         database-wide.  But objects belonging to the extension can be within
@@ -139,6 +148,17 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry>
+      <term><literal>CASCADE</></term>
+      <listitem>
+       <para>
+        Try to install extension including the required dependencies
+        recursively. The <literal>DEFAULT SCHEMA</> option will be propagated
+        to the required extensions.
+       </para>
+      </listitem>
+     </varlistentry>
   </variablelist>
  </refsect1>
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 2b1dcd0..bb5bb37 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -48,6 +48,7 @@
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "storage/fd.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -1173,10 +1174,14 @@ CreateExtension(CreateExtensionStmt *stmt)
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
 	DefElem    *d_old_version = NULL;
+	DefElem	   *d_cascade = NULL;
+	DefElem    *d_default_schema = NULL;
 	char	   *schemaName;
 	Oid			schemaOid;
 	char	   *versionName;
 	char	   *oldVersionName;
+	bool		cascade = false;
+	List	   *cascade_parents = NIL;
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
@@ -1238,7 +1243,7 @@ CreateExtension(CreateExtensionStmt *stmt)
 
 		if (strcmp(defel->defname, "schema") == 0)
 		{
-			if (d_schema)
+			if (d_schema || d_default_schema)
 				ereport(ERROR,
 						(errcode(ERRCODE_SYNTAX_ERROR),
 						 errmsg("conflicting or redundant options")));
@@ -1260,6 +1265,22 @@ CreateExtension(CreateExtensionStmt *stmt)
 						 errmsg("conflicting or redundant options")));
 			d_old_version = defel;
 		}
+		else if (strcmp(defel->defname, "cascade") == 0)
+		{
+			if (d_cascade)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_cascade = defel;
+		}
+		else if (strcmp(defel->defname, "default_schema") == 0)
+		{
+			if (d_default_schema || d_schema)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_default_schema = defel;
+		}
 		else
 			elog(ERROR, "unrecognized option: %s", defel->defname);
 	}
@@ -1380,6 +1401,19 @@ CreateExtension(CreateExtensionStmt *stmt)
 			schemaOid = get_namespace_oid(schemaName, false);
 		}
 	}
+	else if (d_default_schema && d_default_schema->arg)
+	{
+		/*
+		 * User given default schema,
+		 * CREATE EXTENSION ... WITH DEFAULT SCHEMA ...
+		 *
+		 * It only affects relocatable extensions.
+		 */
+		schemaName = strVal(d_default_schema->arg);
+
+		/* If the user is giving us the schema name, it must exist already */
+		schemaOid = get_namespace_oid(schemaName, false);
+	}
 	else
 	{
 		/*
@@ -1402,6 +1436,15 @@ CreateExtension(CreateExtensionStmt *stmt)
 		list_free(search_path);
 	}
 
+	/* Handle the CASCADE option. */
+	if (d_cascade)
+	{
+		cascade = true;
+		if (d_cascade->arg)
+			cascade_parents = (List *) d_cascade->arg;
+	}
+
+
 	/*
 	 * We don't check creation rights on the target namespace here.  If the
 	 * extension script actually creates any objects there, it will fail if
@@ -1429,10 +1472,60 @@ CreateExtension(CreateExtensionStmt *stmt)
 		 */
 		reqext = get_extension_oid(curreq, true);
 		if (!OidIsValid(reqext))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("required extension \"%s\" is not installed",
-							curreq)));
+		{
+			if (cascade)
+			{
+				CreateExtensionStmt *ces;
+				ListCell	   *lc;
+				ObjectAddress	addr;
+
+				ereport(NOTICE,
+						(errmsg("installing required extension \"%s\"",
+								curreq)));
+
+				/* Check for cyclic dependency between extensions. */
+				foreach(lc, cascade_parents)
+				{
+					char	   *pname = (char *) lfirst(lc);
+
+					if (strcmp(pname, curreq) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_RECURSION),
+								 errmsg("cyclic dependency detected between extensions \"%s\" and \"%s\"",
+										curreq, stmt->extname)));
+				}
+
+				/* Create and execute new CREATE EXTENSION statement. */
+				ces = makeNode(CreateExtensionStmt);
+				ces->extname = curreq;
+				ces->if_not_exists = false;
+
+				/*
+				 * Propagate the CASCADE option and add current extension
+				 * to the list for checking the cyclic dependencies.
+				 */
+				cascade_parents = lappend(cascade_parents, stmt->extname);
+				ces->options = list_make1(makeDefElem("cascade",
+													  (Node *) cascade_parents));
+
+				/* Propagate the DEFAULT SCHEMA option if given. */
+				if (d_default_schema && d_default_schema->arg)
+					ces->options = lappend(ces->options, d_default_schema);
+
+				addr = CreateExtension(ces);
+				reqext = addr.objectId;
+
+				/* We leak the DeflElems but probably not worth worrying about */
+				list_free(ces->options);
+				pfree(ces);
+			}
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("required extension \"%s\" is not installed",
+								curreq)));
+		}
+
 		reqschema = get_extension_schema(reqext);
 		requiredExtensions = lappend_oid(requiredExtensions, reqext);
 		requiredSchemas = lappend_oid(requiredSchemas, reqschema);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2b02a2e..9da4b7d 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3849,6 +3849,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("schema", (Node *)makeString($2));
 				}
+			| DEFAULT SCHEMA name
+				{
+					$$ = makeDefElem("default_schema", (Node *)makeString($3));
+				}
 			| VERSION_P NonReservedWord_or_Sconst
 				{
 					$$ = makeDefElem("new_version", (Node *)makeString($2));
@@ -3857,6 +3861,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("old_version", (Node *)makeString($2));
 				}
+			| CASCADE
+				{
+					$$ = makeDefElem("cascade", NULL);
+				}
 		;
 
 /*****************************************************************************
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 0683548..ef54216 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2232,7 +2232,12 @@ psql_completion(const char *text, int start, int end)
 	/* CREATE EXTENSION <name> */
 	else if (pg_strcasecmp(prev3_wd, "CREATE") == 0 &&
 			 pg_strcasecmp(prev2_wd, "EXTENSION") == 0)
-		COMPLETE_WITH_CONST("WITH SCHEMA");
+	{
+		static const char *const list_CREATE_EXTENSION[] =
+		{"WITH SCHEMA", "WITH DEFAULT SCHEMA", "CASCADE", NULL};
+
+		COMPLETE_WITH_LIST(list_CREATE_EXTENSION);
+	}
 
 	/* CREATE FOREIGN */
 	else if (pg_strcasecmp(prev2_wd, "CREATE") == 0 &&
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 8213e23..84b4423 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -8,6 +8,7 @@ SUBDIRS = \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \
+		  test_extensions \
 		  test_parser \
 		  test_rls_hooks \
 		  test_shm_mq \
diff --git a/src/test/modules/test_extensions/.gitignore b/src/test/modules/test_extensions/.gitignore
new file mode 100644
index 0000000..c08326f
--- /dev/null
+++ b/src/test/modules/test_extensions/.gitignore
@@ -0,0 +1,3 @@
+# Generated subdirectories
+/results/
+/tmp_check/
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
new file mode 100644
index 0000000..32f6aab
--- /dev/null
+++ b/src/test/modules/test_extensions/Makefile
@@ -0,0 +1,22 @@
+# src/test/modules/test_extensions/Makefile
+
+MODULE = test_extensions
+PGFILEDESC = "test_extensions - regression testing for EXTENSION support"
+
+EXTENSION = test_ext1 test_ext2 test_ext3 test_ext_cyclic1 test_ext_cyclic2
+DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
+	   test_ext_cyclic1--1.0.sql test_ext_cyclic2--1.0.sql
+
+# test_ddl_deparse must be first
+REGRESS = test_extensions
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_extensions
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
new file mode 100644
index 0000000..f4a5ba1
--- /dev/null
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -0,0 +1,24 @@
+CREATE EXTENSION test_ext1;
+ERROR:  required extension "test_ext2" is not installed
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 CASCADE SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+CREATE EXTENSION test_ext1 CASCADE DEFAULT SCHEMA test_ext;
+NOTICE:  installing required extension "test_ext2"
+NOTICE:  installing required extension "test_ext3"
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+  extname  |  nspname  | extversion | extrelocatable 
+-----------+-----------+------------+----------------
+ test_ext2 | test_ext  | 1.0        | t
+ test_ext3 | test_ext  | 1.0        | t
+ test_ext1 | test_ext1 | 1.0        | f
+(3 rows)
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+NOTICE:  installing required extension "test_ext_cyclic2"
+NOTICE:  installing required extension "test_ext_cyclic1"
+ERROR:  cyclic dependency detected between extensions "test_ext_cyclic1" and "test_ext_cyclic2"
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
new file mode 100644
index 0000000..23a1991
--- /dev/null
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -0,0 +1,15 @@
+CREATE EXTENSION test_ext1;
+
+CREATE SCHEMA test_ext;
+
+CREATE EXTENSION test_ext1 CASCADE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 CASCADE DEFAULT SCHEMA test_ext;
+
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/test_ext1--1.0.sql b/src/test/modules/test_extensions/test_ext1--1.0.sql
new file mode 100644
index 0000000..9a4bb1b
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext1.control b/src/test/modules/test_extensions/test_ext1.control
new file mode 100644
index 0000000..c7ef323
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 1'
+default_version = '1.0'
+schema = 'test_ext1'
+requires = 'test_ext2'
diff --git a/src/test/modules/test_extensions/test_ext2--1.0.sql b/src/test/modules/test_extensions/test_ext2--1.0.sql
new file mode 100644
index 0000000..0f6d4ec
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext2.control b/src/test/modules/test_extensions/test_ext2.control
new file mode 100644
index 0000000..788337e
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext3'
diff --git a/src/test/modules/test_extensions/test_ext3--1.0.sql b/src/test/modules/test_extensions/test_ext3--1.0.sql
new file mode 100644
index 0000000..7dec684
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext3--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext3" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext3.control b/src/test/modules/test_extensions/test_ext3.control
new file mode 100644
index 0000000..5f1afe7
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 3'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
new file mode 100644
index 0000000..81bdaf4
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1.control b/src/test/modules/test_extensions/test_ext_cyclic1.control
new file mode 100644
index 0000000..aaab403
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 1'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic2'
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
new file mode 100644
index 0000000..ae2b3e9
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2.control b/src/test/modules/test_extensions/test_ext_cyclic2.control
new file mode 100644
index 0000000..1e28f96
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic1'
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index d70db40..9b3e31e 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -41,7 +41,7 @@ my $contrib_extrasource = {
 	'seg'  => [ 'contrib/seg/segscan.l',   'contrib/seg/segparse.y' ], };
 my @contrib_excludes = (
 	'commit_ts',      'hstore_plperl', 'hstore_plpython', 'intagg',
-	'ltree_plpython', 'pgcrypto',      'sepgsql');
+	'ltree_plpython', 'pgcrypto',      'sepgsql',         'test_extensions');
 
 # Set of variables for frontend modules
 my $frontend_defines = { 'initdb' => 'FRONTEND' };
-- 
1.9.1

>From a5e59422c162818002f5946542ad47373bf3eb12 Mon Sep 17 00:00:00 2001
From: Petr Jelinek <pjmodos@pjmodos.net>
Date: Sat, 13 Jun 2015 19:49:10 +0200
Subject: [PATCH] CREATE EXTENSION CASCADE

---
 contrib/hstore_plperl/expected/hstore_plperl.out   |   6 +-
 contrib/hstore_plperl/expected/hstore_plperlu.out  |   6 +-
 contrib/hstore_plperl/sql/hstore_plperl.sql        |   4 +-
 contrib/hstore_plperl/sql/hstore_plperlu.sql       |   4 +-
 .../hstore_plpython/expected/hstore_plpython.out   |   4 +-
 contrib/hstore_plpython/sql/hstore_plpython.sql    |   3 +-
 contrib/ltree_plpython/expected/ltree_plpython.out |   4 +-
 contrib/ltree_plpython/sql/ltree_plpython.sql      |   3 +-
 doc/src/sgml/ref/create_extension.sgml             |  40 ++++++
 src/backend/commands/extension.c                   | 158 ++++++++++++++++-----
 src/backend/parser/gram.y                          |   4 +
 src/bin/psql/tab-complete.c                        |   7 +-
 src/test/modules/Makefile                          |   1 +
 src/test/modules/test_extensions/.gitignore        |   3 +
 src/test/modules/test_extensions/Makefile          |  22 +++
 .../test_extensions/expected/test_extensions.out   |  24 ++++
 .../test_extensions/sql/test_extensions.sql        |  15 ++
 .../modules/test_extensions/test_ext1--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext1.control |   5 +
 .../modules/test_extensions/test_ext2--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext2.control |   4 +
 .../modules/test_extensions/test_ext3--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext3.control |   3 +
 .../test_extensions/test_ext_cyclic1--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic1.control       |   4 +
 .../test_extensions/test_ext_cyclic2--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic2.control       |   4 +
 src/tools/msvc/Mkvcbuild.pm                        |   2 +-
 28 files changed, 287 insertions(+), 58 deletions(-)
 create mode 100644 src/test/modules/test_extensions/.gitignore
 create mode 100644 src/test/modules/test_extensions/Makefile
 create mode 100644 src/test/modules/test_extensions/expected/test_extensions.out
 create mode 100644 src/test/modules/test_extensions/sql/test_extensions.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1.control
 create mode 100644 src/test/modules/test_extensions/test_ext2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext2.control
 create mode 100644 src/test/modules/test_extensions/test_ext3--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext3.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2.control

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index cf384eb..25fc506 100644
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperl"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/expected/hstore_plperlu.out b/contrib/hstore_plperl/expected/hstore_plperlu.out
index 8c689ad..3fc3201 100644
--- a/contrib/hstore_plperl/expected/hstore_plperlu.out
+++ b/contrib/hstore_plperl/expected/hstore_plperlu.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperlu"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 0f70f14..9398aed 100644
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plperl/sql/hstore_plperlu.sql b/contrib/hstore_plperl/sql/hstore_plperlu.sql
index 3cfb2fd..8d8508c 100644
--- a/contrib/hstore_plperl/sql/hstore_plperlu.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperlu.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index b7a6a92..55f4efe 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 -- test hstore -> python
 CREATE FUNCTION test1(val hstore) RETURNS int
 LANGUAGE plpythonu
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index 9ff2ebc..d55beda 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
 
 
 -- test hstore -> python
diff --git a/contrib/ltree_plpython/expected/ltree_plpython.out b/contrib/ltree_plpython/expected/ltree_plpython.out
index 934529e..9bee6be 100644
--- a/contrib/ltree_plpython/expected/ltree_plpython.out
+++ b/contrib/ltree_plpython/expected/ltree_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 CREATE FUNCTION test1(val ltree) RETURNS int
 LANGUAGE plpythonu
 TRANSFORM FOR TYPE ltree
diff --git a/contrib/ltree_plpython/sql/ltree_plpython.sql b/contrib/ltree_plpython/sql/ltree_plpython.sql
index f08ff6a..210f542 100644
--- a/contrib/ltree_plpython/sql/ltree_plpython.sql
+++ b/contrib/ltree_plpython/sql/ltree_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
 
 
 CREATE FUNCTION test1(val ltree) RETURNS int
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index a1e7e4f8..715dd23 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -25,6 +25,7 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
     [ WITH ] [ SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
              [ VERSION <replaceable class="parameter">version</replaceable> ]
              [ FROM <replaceable class="parameter">old_version</replaceable> ]
+             [ CASCADE ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -95,6 +96,34 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         schema either, the current default object creation schema is used.
        </para>
        <para>
+        In case the extension specifies schema in its control file, the schema
+        can't be overriden using <literal>SCHEMA</> parameter. The actual
+        behavior of the <literal>SCHEMA</> parameter in this case will depend
+        on circumstances:
+        <itemizedlist>
+         <listitem>
+          <para>
+           If schema specified by <literal>SCHEMA</> parameter matches the one
+           in control file, it will be used normally as there is no conflict.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If <literal>CASCADE</> parameter is given, the <literal>SCHEMA</>
+           parameter will only be used by the missing required extensions which
+           do not specify the schema in their control files.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If schema is not same as the one in extension's control file and
+           the <literal>CASCADE</> parameter is not given, error will be
+           thrown.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+       <para>
         Remember that the extension itself is not considered to be within any
         schema: extensions have unqualified names that must be unique
         database-wide.  But objects belonging to the extension can be within
@@ -139,6 +168,17 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry>
+      <term><literal>CASCADE</></term>
+      <listitem>
+       <para>
+        Try to install extension including the required dependencies
+        recursively. The <literal>SCHEMA</> option will be propagated
+        to the required extensions.
+       </para>
+      </listitem>
+     </varlistentry>
   </variablelist>
  </refsect1>
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 2b1dcd0..f73a8ce 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -48,6 +48,7 @@
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "storage/fd.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -1173,10 +1174,12 @@ CreateExtension(CreateExtensionStmt *stmt)
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
 	DefElem    *d_old_version = NULL;
+	DefElem	   *d_cascade = NULL;
 	char	   *schemaName;
-	Oid			schemaOid;
+	Oid			schemaOid = InvalidOid;
 	char	   *versionName;
 	char	   *oldVersionName;
+	List	   *cascade_parents = NIL;
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
@@ -1260,6 +1263,14 @@ CreateExtension(CreateExtensionStmt *stmt)
 						 errmsg("conflicting or redundant options")));
 			d_old_version = defel;
 		}
+		else if (strcmp(defel->defname, "cascade") == 0)
+		{
+			if (d_cascade)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_cascade = defel;
+		}
 		else
 			elog(ERROR, "unrecognized option: %s", defel->defname);
 	}
@@ -1330,6 +1341,13 @@ CreateExtension(CreateExtensionStmt *stmt)
 	 */
 	control = read_extension_aux_control_file(pcontrol, versionName);
 
+	/* Handle the CASCADE option. */
+	if (d_cascade)
+	{
+		if (d_cascade->arg)
+			cascade_parents = (List *) d_cascade->arg;
+	}
+
 	/*
 	 * Determine the target schema to install the extension into
 	 */
@@ -1337,54 +1355,72 @@ CreateExtension(CreateExtensionStmt *stmt)
 	{
 		/*
 		 * User given schema, CREATE EXTENSION ... WITH SCHEMA ...
-		 *
-		 * It's an error to give a schema different from control->schema if
-		 * control->schema is specified.
 		 */
 		schemaName = strVal(d_schema->arg);
 
-		if (control->schema != NULL &&
-			strcmp(control->schema, schemaName) != 0)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				errmsg("extension \"%s\" must be installed in schema \"%s\"",
-					   control->name,
-					   control->schema)));
-
-		/* If the user is giving us the schema name, it must exist already */
+		/* If the user is giving us the schema name, it must exist already. */
 		schemaOid = get_namespace_oid(schemaName, false);
 	}
-	else if (control->schema != NULL)
+
+	if (control->schema != NULL)
 	{
 		/*
 		 * The extension is not relocatable and the author gave us a schema
-		 * for it.  We create the schema here if it does not already exist.
+		 * for it.
 		 */
-		schemaName = control->schema;
-		schemaOid = get_namespace_oid(schemaName, true);
 
-		if (schemaOid == InvalidOid)
+		/*
+		 * User given schema. Unless CASCADE is specified, it's an error to
+		 * give schema different from the one specified by author. When
+		 * CASCADE is specified, we just ignore the schema given by user and
+		 * use the one from control file as if no schema was given by user.
+		 */
+		if (OidIsValid(schemaOid))
 		{
-			CreateSchemaStmt *csstmt = makeNode(CreateSchemaStmt);
+			if (d_cascade == NULL &&
+				strcmp(control->schema, schemaName) != 0)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("extension \"%s\" must be installed in schema \"%s\"",
+					   control->name,
+					   control->schema)));
+			else
+				schemaOid = InvalidOid;
+		}
 
-			csstmt->schemaname = schemaName;
-			csstmt->authrole = NULL;	/* will be created by current user */
-			csstmt->schemaElts = NIL;
-			csstmt->if_not_exists = false;
-			CreateSchemaCommand(csstmt, NULL);
+		/*
+		 * User didn't provide schema or we are not using it, create the
+		 * schema specified by extension author if it does not exist yet.
+		 */
+		if (!OidIsValid(schemaOid))
+		{
+			schemaName = control->schema;
+			schemaOid = get_namespace_oid(control->schema, true);
 
-			/*
-			 * CreateSchemaCommand includes CommandCounterIncrement, so new
-			 * schema is now visible
-			 */
-			schemaOid = get_namespace_oid(schemaName, false);
+			if (!OidIsValid(schemaOid))
+			{
+				CreateSchemaStmt *csstmt = makeNode(CreateSchemaStmt);
+
+				csstmt->schemaname = schemaName;
+				csstmt->authrole = NULL;	/* will be created by current user */
+				csstmt->schemaElts = NIL;
+				csstmt->if_not_exists = false;
+				CreateSchemaCommand(csstmt, NULL);
+
+				/*
+				 * CreateSchemaCommand includes CommandCounterIncrement, so new
+				 * schema is now visible
+				 */
+				schemaOid = get_namespace_oid(schemaName, false);
+			}
 		}
 	}
-	else
+	else if (!OidIsValid(schemaOid))
 	{
 		/*
-		 * Else, use the current default creation namespace, which is the
-		 * first explicit entry in the search_path.
+		 * Neither user nor author of the extension specified schema, use the
+		 * current default creation namespace, which is the first explicit
+		 * entry in the search_path.
 		 */
 		List	   *search_path = fetch_search_path(false);
 
@@ -1429,10 +1465,60 @@ CreateExtension(CreateExtensionStmt *stmt)
 		 */
 		reqext = get_extension_oid(curreq, true);
 		if (!OidIsValid(reqext))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("required extension \"%s\" is not installed",
-							curreq)));
+		{
+			if (d_cascade)
+			{
+				CreateExtensionStmt *ces;
+				ListCell	   *lc;
+				ObjectAddress	addr;
+
+				ereport(NOTICE,
+						(errmsg("installing required extension \"%s\"",
+								curreq)));
+
+				/* Check for cyclic dependency between extensions. */
+				foreach(lc, cascade_parents)
+				{
+					char	   *pname = (char *) lfirst(lc);
+
+					if (strcmp(pname, curreq) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_RECURSION),
+								 errmsg("cyclic dependency detected between extensions \"%s\" and \"%s\"",
+										curreq, stmt->extname)));
+				}
+
+				/* Create and execute new CREATE EXTENSION statement. */
+				ces = makeNode(CreateExtensionStmt);
+				ces->extname = curreq;
+				ces->if_not_exists = false;
+
+				/*
+				 * Propagate the CASCADE option and add current extension
+				 * to the list for checking the cyclic dependencies.
+				 */
+				cascade_parents = lappend(cascade_parents, stmt->extname);
+				ces->options = list_make1(makeDefElem("cascade",
+													  (Node *) cascade_parents));
+
+				/* Propagate the SCHEMA option if given. */
+				if (d_schema && d_schema->arg)
+					ces->options = lappend(ces->options, d_schema);
+
+				addr = CreateExtension(ces);
+				reqext = addr.objectId;
+
+				/* We leak the DeflElems but probably not worth worrying about */
+				list_free(ces->options);
+				pfree(ces);
+			}
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("required extension \"%s\" is not installed",
+								curreq)));
+		}
+
 		reqschema = get_extension_schema(reqext);
 		requiredExtensions = lappend_oid(requiredExtensions, reqext);
 		requiredSchemas = lappend_oid(requiredSchemas, reqschema);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2b02a2e..44c8ed5 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3857,6 +3857,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("old_version", (Node *)makeString($2));
 				}
+			| CASCADE
+				{
+					$$ = makeDefElem("cascade", NULL);
+				}
 		;
 
 /*****************************************************************************
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 9596af6..89ab420 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2245,7 +2245,12 @@ psql_completion(const char *text, int start, int end)
 	/* CREATE EXTENSION <name> */
 	else if (pg_strcasecmp(prev3_wd, "CREATE") == 0 &&
 			 pg_strcasecmp(prev2_wd, "EXTENSION") == 0)
-		COMPLETE_WITH_CONST("WITH SCHEMA");
+	{
+		static const char *const list_CREATE_EXTENSION[] =
+		{"WITH SCHEMA", "CASCADE", NULL};
+
+		COMPLETE_WITH_LIST(list_CREATE_EXTENSION);
+	}
 
 	/* CREATE FOREIGN */
 	else if (pg_strcasecmp(prev2_wd, "CREATE") == 0 &&
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 8213e23..84b4423 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -8,6 +8,7 @@ SUBDIRS = \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \
+		  test_extensions \
 		  test_parser \
 		  test_rls_hooks \
 		  test_shm_mq \
diff --git a/src/test/modules/test_extensions/.gitignore b/src/test/modules/test_extensions/.gitignore
new file mode 100644
index 0000000..c08326f
--- /dev/null
+++ b/src/test/modules/test_extensions/.gitignore
@@ -0,0 +1,3 @@
+# Generated subdirectories
+/results/
+/tmp_check/
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
new file mode 100644
index 0000000..32f6aab
--- /dev/null
+++ b/src/test/modules/test_extensions/Makefile
@@ -0,0 +1,22 @@
+# src/test/modules/test_extensions/Makefile
+
+MODULE = test_extensions
+PGFILEDESC = "test_extensions - regression testing for EXTENSION support"
+
+EXTENSION = test_ext1 test_ext2 test_ext3 test_ext_cyclic1 test_ext_cyclic2
+DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
+	   test_ext_cyclic1--1.0.sql test_ext_cyclic2--1.0.sql
+
+# test_ddl_deparse must be first
+REGRESS = test_extensions
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_extensions
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
new file mode 100644
index 0000000..b32ad0e
--- /dev/null
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -0,0 +1,24 @@
+CREATE EXTENSION test_ext1;
+ERROR:  required extension "test_ext2" is not installed
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+NOTICE:  installing required extension "test_ext2"
+NOTICE:  installing required extension "test_ext3"
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+  extname  |  nspname  | extversion | extrelocatable 
+-----------+-----------+------------+----------------
+ test_ext2 | test_ext  | 1.0        | t
+ test_ext3 | test_ext  | 1.0        | t
+ test_ext1 | test_ext1 | 1.0        | f
+(3 rows)
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+NOTICE:  installing required extension "test_ext_cyclic2"
+NOTICE:  installing required extension "test_ext_cyclic1"
+ERROR:  cyclic dependency detected between extensions "test_ext_cyclic1" and "test_ext_cyclic2"
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
new file mode 100644
index 0000000..9c2c040
--- /dev/null
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -0,0 +1,15 @@
+CREATE EXTENSION test_ext1;
+
+CREATE SCHEMA test_ext;
+
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/test_ext1--1.0.sql b/src/test/modules/test_extensions/test_ext1--1.0.sql
new file mode 100644
index 0000000..9a4bb1b
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext1.control b/src/test/modules/test_extensions/test_ext1.control
new file mode 100644
index 0000000..ae50cd8
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1.control
@@ -0,0 +1,5 @@
+comment = 'Test extension 1'
+default_version = '1.0'
+schema = 'test_ext1'
+relocatable = false
+requires = 'test_ext2'
diff --git a/src/test/modules/test_extensions/test_ext2--1.0.sql b/src/test/modules/test_extensions/test_ext2--1.0.sql
new file mode 100644
index 0000000..0f6d4ec
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext2.control b/src/test/modules/test_extensions/test_ext2.control
new file mode 100644
index 0000000..788337e
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext3'
diff --git a/src/test/modules/test_extensions/test_ext3--1.0.sql b/src/test/modules/test_extensions/test_ext3--1.0.sql
new file mode 100644
index 0000000..7dec684
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext3--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext3" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext3.control b/src/test/modules/test_extensions/test_ext3.control
new file mode 100644
index 0000000..5f1afe7
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 3'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
new file mode 100644
index 0000000..81bdaf4
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1.control b/src/test/modules/test_extensions/test_ext_cyclic1.control
new file mode 100644
index 0000000..aaab403
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 1'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic2'
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
new file mode 100644
index 0000000..ae2b3e9
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2.control b/src/test/modules/test_extensions/test_ext_cyclic2.control
new file mode 100644
index 0000000..1e28f96
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic1'
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index d70db40..9b3e31e 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -41,7 +41,7 @@ my $contrib_extrasource = {
 	'seg'  => [ 'contrib/seg/segscan.l',   'contrib/seg/segparse.y' ], };
 my @contrib_excludes = (
 	'commit_ts',      'hstore_plperl', 'hstore_plpython', 'intagg',
-	'ltree_plpython', 'pgcrypto',      'sepgsql');
+	'ltree_plpython', 'pgcrypto',      'sepgsql',         'test_extensions');
 
 # Set of variables for frontend modules
 my $frontend_defines = { 'initdb' => 'FRONTEND' };
-- 
1.9.1

From c13e2919466bb9001666a63361ff560d1779bde4 Mon Sep 17 00:00:00 2001
From: Petr Jelinek <pjmodos@pjmodos.net>
Date: Sat, 13 Jun 2015 19:49:10 +0200
Subject: [PATCH] CREATE EXTENSION CASCADE

---
 contrib/hstore_plperl/expected/hstore_plperl.out   |   6 +-
 contrib/hstore_plperl/expected/hstore_plperlu.out  |   6 +-
 contrib/hstore_plperl/sql/hstore_plperl.sql        |   4 +-
 contrib/hstore_plperl/sql/hstore_plperlu.sql       |   4 +-
 .../hstore_plpython/expected/hstore_plpython.out   |   4 +-
 contrib/hstore_plpython/sql/hstore_plpython.sql    |   3 +-
 contrib/ltree_plpython/expected/ltree_plpython.out |   4 +-
 contrib/ltree_plpython/sql/ltree_plpython.sql      |   3 +-
 doc/src/sgml/ref/create_extension.sgml             |  42 +++++++++
 src/backend/commands/extension.c                   | 103 ++++++++++++++++++---
 src/backend/parser/gram.y                          |   4 +
 src/bin/psql/tab-complete.c                        |   7 +-
 src/test/modules/Makefile                          |   1 +
 src/test/modules/test_extensions/.gitignore        |   3 +
 src/test/modules/test_extensions/Makefile          |  21 +++++
 .../test_extensions/expected/test_extensions.out   |  30 ++++++
 .../test_extensions/sql/test_extensions.sql        |  18 ++++
 .../modules/test_extensions/test_ext1--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext1.control |   5 +
 .../modules/test_extensions/test_ext2--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext2.control |   4 +
 .../modules/test_extensions/test_ext3--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext3.control |   3 +
 .../test_extensions/test_ext_cyclic1--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic1.control       |   4 +
 .../test_extensions/test_ext_cyclic2--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic2.control       |   4 +
 src/tools/msvc/Mkvcbuild.pm                        |   2 +-
 28 files changed, 263 insertions(+), 37 deletions(-)
 create mode 100644 src/test/modules/test_extensions/.gitignore
 create mode 100644 src/test/modules/test_extensions/Makefile
 create mode 100644 src/test/modules/test_extensions/expected/test_extensions.out
 create mode 100644 src/test/modules/test_extensions/sql/test_extensions.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1.control
 create mode 100644 src/test/modules/test_extensions/test_ext2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext2.control
 create mode 100644 src/test/modules/test_extensions/test_ext3--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext3.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2.control

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index cf384eb..25fc506 100644
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperl"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/expected/hstore_plperlu.out b/contrib/hstore_plperl/expected/hstore_plperlu.out
index 8c689ad..3fc3201 100644
--- a/contrib/hstore_plperl/expected/hstore_plperlu.out
+++ b/contrib/hstore_plperl/expected/hstore_plperlu.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperlu"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 0f70f14..9398aed 100644
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plperl/sql/hstore_plperlu.sql b/contrib/hstore_plperl/sql/hstore_plperlu.sql
index 3cfb2fd..8d8508c 100644
--- a/contrib/hstore_plperl/sql/hstore_plperlu.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperlu.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index b7a6a92..55f4efe 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 -- test hstore -> python
 CREATE FUNCTION test1(val hstore) RETURNS int
 LANGUAGE plpythonu
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index 9ff2ebc..d55beda 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
 
 
 -- test hstore -> python
diff --git a/contrib/ltree_plpython/expected/ltree_plpython.out b/contrib/ltree_plpython/expected/ltree_plpython.out
index 934529e..9bee6be 100644
--- a/contrib/ltree_plpython/expected/ltree_plpython.out
+++ b/contrib/ltree_plpython/expected/ltree_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 CREATE FUNCTION test1(val ltree) RETURNS int
 LANGUAGE plpythonu
 TRANSFORM FOR TYPE ltree
diff --git a/contrib/ltree_plpython/sql/ltree_plpython.sql b/contrib/ltree_plpython/sql/ltree_plpython.sql
index f08ff6a..210f542 100644
--- a/contrib/ltree_plpython/sql/ltree_plpython.sql
+++ b/contrib/ltree_plpython/sql/ltree_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
 
 
 CREATE FUNCTION test1(val ltree) RETURNS int
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index a1e7e4f8..6f4d3f9 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -25,6 +25,7 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
     [ WITH ] [ SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
              [ VERSION <replaceable class="parameter">version</replaceable> ]
              [ FROM <replaceable class="parameter">old_version</replaceable> ]
+             [ CASCADE ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -95,6 +96,36 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         schema either, the current default object creation schema is used.
        </para>
        <para>
+        In case the extension specifies schema in its control file, the schema
+        can't be overriden using <literal>SCHEMA</> parameter. The actual
+        behavior of the <literal>SCHEMA</> parameter in this case will depend
+        on circumstances:
+        <itemizedlist>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> matches
+           the schema in control file, it will be used normally as there is no
+           conflict.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If <literal>CASCADE</> parameter is given, the
+           <replaceable class="parameter">schema_name</replaceable> will only
+           be used for the missing required extensions which do not specify
+           the schema in their control files.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> is not
+           same as the one in extension's control file and the
+           <literal>CASCADE</> parameter is not given, error will be thrown.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+       <para>
         Remember that the extension itself is not considered to be within any
         schema: extensions have unqualified names that must be unique
         database-wide.  But objects belonging to the extension can be within
@@ -139,6 +170,17 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry>
+      <term><literal>CASCADE</></term>
+      <listitem>
+       <para>
+        Try to install extension including the required dependencies
+        recursively. The <literal>SCHEMA</> option will be propagated
+        to the required extensions.
+       </para>
+      </listitem>
+     </varlistentry>
   </variablelist>
  </refsect1>
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 2b1dcd0..0dfbe7a 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -48,6 +48,7 @@
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "storage/fd.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -1173,10 +1174,12 @@ CreateExtension(CreateExtensionStmt *stmt)
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
 	DefElem    *d_old_version = NULL;
+	DefElem	   *d_cascade = NULL;
 	char	   *schemaName;
-	Oid			schemaOid;
+	Oid			schemaOid = InvalidOid;
 	char	   *versionName;
 	char	   *oldVersionName;
+	List	   *cascade_parents = NIL;
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
@@ -1260,6 +1263,14 @@ CreateExtension(CreateExtensionStmt *stmt)
 						 errmsg("conflicting or redundant options")));
 			d_old_version = defel;
 		}
+		else if (strcmp(defel->defname, "cascade") == 0)
+		{
+			if (d_cascade)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_cascade = defel;
+		}
 		else
 			elog(ERROR, "unrecognized option: %s", defel->defname);
 	}
@@ -1330,6 +1341,14 @@ CreateExtension(CreateExtensionStmt *stmt)
 	 */
 	control = read_extension_aux_control_file(pcontrol, versionName);
 
+
+	/* Handle the CASCADE option. */
+	if (d_cascade)
+	{
+		if (d_cascade->arg)
+			cascade_parents = (List *) d_cascade->arg;
+	}
+
 	/*
 	 * Determine the target schema to install the extension into
 	 */
@@ -1338,12 +1357,12 @@ CreateExtension(CreateExtensionStmt *stmt)
 		/*
 		 * User given schema, CREATE EXTENSION ... WITH SCHEMA ...
 		 *
-		 * It's an error to give a schema different from control->schema if
-		 * control->schema is specified.
+		 * Unless CASCADE parameter was given, it's an error to give a schema
+		 * different from control->schema if control->schema is specified.
 		 */
 		schemaName = strVal(d_schema->arg);
 
-		if (control->schema != NULL &&
+		if (d_cascade == NULL && control->schema != NULL &&
 			strcmp(control->schema, schemaName) != 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -1351,19 +1370,22 @@ CreateExtension(CreateExtensionStmt *stmt)
 					   control->name,
 					   control->schema)));
 
-		/* If the user is giving us the schema name, it must exist already */
+		/* If the user is giving us the schema name, it must exist already. */
 		schemaOid = get_namespace_oid(schemaName, false);
 	}
-	else if (control->schema != NULL)
+
+	if (control->schema != NULL)
 	{
 		/*
 		 * The extension is not relocatable and the author gave us a schema
 		 * for it.  We create the schema here if it does not already exist.
+		 *
+		 * We already did the validation of user specified schema above.
 		 */
 		schemaName = control->schema;
 		schemaOid = get_namespace_oid(schemaName, true);
 
-		if (schemaOid == InvalidOid)
+		if (!OidIsValid(schemaOid))
 		{
 			CreateSchemaStmt *csstmt = makeNode(CreateSchemaStmt);
 
@@ -1375,16 +1397,17 @@ CreateExtension(CreateExtensionStmt *stmt)
 
 			/*
 			 * CreateSchemaCommand includes CommandCounterIncrement, so new
-			 * schema is now visible
+			 * schema is now visible.
 			 */
 			schemaOid = get_namespace_oid(schemaName, false);
 		}
 	}
-	else
+	else if (!OidIsValid(schemaOid))
 	{
 		/*
-		 * Else, use the current default creation namespace, which is the
-		 * first explicit entry in the search_path.
+		 * Neither user nor author of the extension specified schema, use the
+		 * current default creation namespace, which is the first explicit
+		 * entry in the search_path.
 		 */
 		List	   *search_path = fetch_search_path(false);
 
@@ -1429,10 +1452,60 @@ CreateExtension(CreateExtensionStmt *stmt)
 		 */
 		reqext = get_extension_oid(curreq, true);
 		if (!OidIsValid(reqext))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("required extension \"%s\" is not installed",
-							curreq)));
+		{
+			if (d_cascade)
+			{
+				CreateExtensionStmt *ces;
+				ListCell	   *lc;
+				ObjectAddress	addr;
+
+				ereport(NOTICE,
+						(errmsg("installing required extension \"%s\"",
+								curreq)));
+
+				/* Check for cyclic dependency between extensions. */
+				foreach(lc, cascade_parents)
+				{
+					char	   *pname = (char *) lfirst(lc);
+
+					if (strcmp(pname, curreq) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_RECURSION),
+								 errmsg("cyclic dependency detected between extensions \"%s\" and \"%s\"",
+										curreq, stmt->extname)));
+				}
+
+				/* Create and execute new CREATE EXTENSION statement. */
+				ces = makeNode(CreateExtensionStmt);
+				ces->extname = curreq;
+				ces->if_not_exists = false;
+
+				/*
+				 * Propagate the CASCADE option and add current extension
+				 * to the list for checking the cyclic dependencies.
+				 */
+				cascade_parents = lappend(cascade_parents, stmt->extname);
+				ces->options = list_make1(makeDefElem("cascade",
+													  (Node *) cascade_parents));
+
+				/* Propagate the SCHEMA option if given. */
+				if (d_schema && d_schema->arg)
+					ces->options = lappend(ces->options, d_schema);
+
+				addr = CreateExtension(ces);
+				reqext = addr.objectId;
+
+				/* We leak the DeflElems but probably not worth worrying about */
+				list_free(ces->options);
+				pfree(ces);
+			}
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("required extension \"%s\" is not installed",
+								curreq)));
+		}
+
 		reqschema = get_extension_schema(reqext);
 		requiredExtensions = lappend_oid(requiredExtensions, reqext);
 		requiredSchemas = lappend_oid(requiredSchemas, reqschema);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2b02a2e..44c8ed5 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3857,6 +3857,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("old_version", (Node *)makeString($2));
 				}
+			| CASCADE
+				{
+					$$ = makeDefElem("cascade", NULL);
+				}
 		;
 
 /*****************************************************************************
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 9596af6..89ab420 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2245,7 +2245,12 @@ psql_completion(const char *text, int start, int end)
 	/* CREATE EXTENSION <name> */
 	else if (pg_strcasecmp(prev3_wd, "CREATE") == 0 &&
 			 pg_strcasecmp(prev2_wd, "EXTENSION") == 0)
-		COMPLETE_WITH_CONST("WITH SCHEMA");
+	{
+		static const char *const list_CREATE_EXTENSION[] =
+		{"WITH SCHEMA", "CASCADE", NULL};
+
+		COMPLETE_WITH_LIST(list_CREATE_EXTENSION);
+	}
 
 	/* CREATE FOREIGN */
 	else if (pg_strcasecmp(prev2_wd, "CREATE") == 0 &&
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 8213e23..84b4423 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -8,6 +8,7 @@ SUBDIRS = \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \
+		  test_extensions \
 		  test_parser \
 		  test_rls_hooks \
 		  test_shm_mq \
diff --git a/src/test/modules/test_extensions/.gitignore b/src/test/modules/test_extensions/.gitignore
new file mode 100644
index 0000000..c08326f
--- /dev/null
+++ b/src/test/modules/test_extensions/.gitignore
@@ -0,0 +1,3 @@
+# Generated subdirectories
+/results/
+/tmp_check/
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
new file mode 100644
index 0000000..6c50e6c
--- /dev/null
+++ b/src/test/modules/test_extensions/Makefile
@@ -0,0 +1,21 @@
+# src/test/modules/test_extensions/Makefile
+
+MODULE = test_extensions
+PGFILEDESC = "test_extensions - regression testing for EXTENSION support"
+
+EXTENSION = test_ext1 test_ext2 test_ext3 test_ext_cyclic1 test_ext_cyclic2
+DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
+	   test_ext_cyclic1--1.0.sql test_ext_cyclic2--1.0.sql
+
+REGRESS = test_extensions
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_extensions
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
new file mode 100644
index 0000000..6cc24e2
--- /dev/null
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -0,0 +1,30 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+ERROR:  required extension "test_ext2" is not installed
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+ERROR:  schema "test_ext1" does not exist
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+NOTICE:  installing required extension "test_ext2"
+NOTICE:  installing required extension "test_ext3"
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+  extname  |  nspname  | extversion | extrelocatable 
+-----------+-----------+------------+----------------
+ test_ext2 | test_ext  | 1.0        | t
+ test_ext3 | test_ext  | 1.0        | t
+ test_ext1 | test_ext1 | 1.0        | f
+(3 rows)
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+NOTICE:  installing required extension "test_ext_cyclic2"
+NOTICE:  installing required extension "test_ext_cyclic1"
+ERROR:  cyclic dependency detected between extensions "test_ext_cyclic1" and "test_ext_cyclic2"
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
new file mode 100644
index 0000000..640ac9b
--- /dev/null
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -0,0 +1,18 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/test_ext1--1.0.sql b/src/test/modules/test_extensions/test_ext1--1.0.sql
new file mode 100644
index 0000000..9a4bb1b
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext1.control b/src/test/modules/test_extensions/test_ext1.control
new file mode 100644
index 0000000..ae50cd8
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1.control
@@ -0,0 +1,5 @@
+comment = 'Test extension 1'
+default_version = '1.0'
+schema = 'test_ext1'
+relocatable = false
+requires = 'test_ext2'
diff --git a/src/test/modules/test_extensions/test_ext2--1.0.sql b/src/test/modules/test_extensions/test_ext2--1.0.sql
new file mode 100644
index 0000000..0f6d4ec
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext2.control b/src/test/modules/test_extensions/test_ext2.control
new file mode 100644
index 0000000..788337e
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext3'
diff --git a/src/test/modules/test_extensions/test_ext3--1.0.sql b/src/test/modules/test_extensions/test_ext3--1.0.sql
new file mode 100644
index 0000000..7dec684
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext3--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext3" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext3.control b/src/test/modules/test_extensions/test_ext3.control
new file mode 100644
index 0000000..5f1afe7
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 3'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
new file mode 100644
index 0000000..81bdaf4
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1.control b/src/test/modules/test_extensions/test_ext_cyclic1.control
new file mode 100644
index 0000000..aaab403
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 1'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic2'
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
new file mode 100644
index 0000000..ae2b3e9
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2.control b/src/test/modules/test_extensions/test_ext_cyclic2.control
new file mode 100644
index 0000000..1e28f96
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic1'
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index d70db40..9b3e31e 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -41,7 +41,7 @@ my $contrib_extrasource = {
 	'seg'  => [ 'contrib/seg/segscan.l',   'contrib/seg/segparse.y' ], };
 my @contrib_excludes = (
 	'commit_ts',      'hstore_plperl', 'hstore_plpython', 'intagg',
-	'ltree_plpython', 'pgcrypto',      'sepgsql');
+	'ltree_plpython', 'pgcrypto',      'sepgsql',         'test_extensions');
 
 # Set of variables for frontend modules
 my $frontend_defines = { 'initdb' => 'FRONTEND' };
-- 
1.9.1

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index cf384eb..25fc506 100644
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperl"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/expected/hstore_plperlu.out b/contrib/hstore_plperl/expected/hstore_plperlu.out
index 8c689ad..3fc3201 100644
--- a/contrib/hstore_plperl/expected/hstore_plperlu.out
+++ b/contrib/hstore_plperl/expected/hstore_plperlu.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperlu"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 0f70f14..9398aed 100644
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plperl/sql/hstore_plperlu.sql b/contrib/hstore_plperl/sql/hstore_plperlu.sql
index 3cfb2fd..8d8508c 100644
--- a/contrib/hstore_plperl/sql/hstore_plperlu.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperlu.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index b7a6a92..55f4efe 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 -- test hstore -> python
 CREATE FUNCTION test1(val hstore) RETURNS int
 LANGUAGE plpythonu
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index 9ff2ebc..d55beda 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
 
 
 -- test hstore -> python
diff --git a/contrib/ltree_plpython/expected/ltree_plpython.out b/contrib/ltree_plpython/expected/ltree_plpython.out
index 934529e..9bee6be 100644
--- a/contrib/ltree_plpython/expected/ltree_plpython.out
+++ b/contrib/ltree_plpython/expected/ltree_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 CREATE FUNCTION test1(val ltree) RETURNS int
 LANGUAGE plpythonu
 TRANSFORM FOR TYPE ltree
diff --git a/contrib/ltree_plpython/sql/ltree_plpython.sql b/contrib/ltree_plpython/sql/ltree_plpython.sql
index f08ff6a..210f542 100644
--- a/contrib/ltree_plpython/sql/ltree_plpython.sql
+++ b/contrib/ltree_plpython/sql/ltree_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
 
 
 CREATE FUNCTION test1(val ltree) RETURNS int
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index a1e7e4f8..fc85f80 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -25,6 +25,7 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
     [ WITH ] [ SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
              [ VERSION <replaceable class="parameter">version</replaceable> ]
              [ FROM <replaceable class="parameter">old_version</replaceable> ]
+             [ CASCADE ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -91,8 +92,38 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         The name of the schema in which to install the extension's
         objects, given that the extension allows its contents to be
         relocated.  The named schema must already exist.
-        If not specified, and the extension's control file does not specify a
-        schema either, the current default object creation schema is used.
+        If not specified, and the extension control file does not define
+        <literal>schema</> either, the current default object creation
+        schema is used.
+       </para>
+       <para>
+        If the extension specifies <literal>schema</> in its control file,
+        the schema cannot be overriden with <literal>SCHEMA</> clause.
+        The <literal>SCHEMA</> clause in this case works as follows:
+        <itemizedlist>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> matches
+           the schema in control file, it will be used normally as there is no
+           conflict.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If the <literal>CASCADE</> clause is defined, the
+           <replaceable class="parameter">schema_name</replaceable> will only
+           be used for the missing required extensions which do not specify
+           <literal>schema</> in their control files.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> is not
+           the same as the one in extension's control file and the
+           <literal>CASCADE</> clause is not given, error will be thrown.
+          </para>
+         </listitem>
+        </itemizedlist>
        </para>
        <para>
         Remember that the extension itself is not considered to be within any
@@ -139,6 +170,18 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry>
+      <term><literal>CASCADE</></term>
+      <listitem>
+       <para>
+        Try to install extension including the required dependencies
+        recursively. The <literal>SCHEMA</> option will be propagated
+        to the required extensions.  Other options are not recursively
+        applied when using this clause.
+       </para>
+      </listitem>
+     </varlistentry>
   </variablelist>
  </refsect1>
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 2b1dcd0..0dfbe7a 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -48,6 +48,7 @@
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "storage/fd.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -1173,10 +1174,12 @@ CreateExtension(CreateExtensionStmt *stmt)
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
 	DefElem    *d_old_version = NULL;
+	DefElem	   *d_cascade = NULL;
 	char	   *schemaName;
-	Oid			schemaOid;
+	Oid			schemaOid = InvalidOid;
 	char	   *versionName;
 	char	   *oldVersionName;
+	List	   *cascade_parents = NIL;
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
@@ -1260,6 +1263,14 @@ CreateExtension(CreateExtensionStmt *stmt)
 						 errmsg("conflicting or redundant options")));
 			d_old_version = defel;
 		}
+		else if (strcmp(defel->defname, "cascade") == 0)
+		{
+			if (d_cascade)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_cascade = defel;
+		}
 		else
 			elog(ERROR, "unrecognized option: %s", defel->defname);
 	}
@@ -1330,6 +1341,14 @@ CreateExtension(CreateExtensionStmt *stmt)
 	 */
 	control = read_extension_aux_control_file(pcontrol, versionName);
 
+
+	/* Handle the CASCADE option. */
+	if (d_cascade)
+	{
+		if (d_cascade->arg)
+			cascade_parents = (List *) d_cascade->arg;
+	}
+
 	/*
 	 * Determine the target schema to install the extension into
 	 */
@@ -1338,12 +1357,12 @@ CreateExtension(CreateExtensionStmt *stmt)
 		/*
 		 * User given schema, CREATE EXTENSION ... WITH SCHEMA ...
 		 *
-		 * It's an error to give a schema different from control->schema if
-		 * control->schema is specified.
+		 * Unless CASCADE parameter was given, it's an error to give a schema
+		 * different from control->schema if control->schema is specified.
 		 */
 		schemaName = strVal(d_schema->arg);
 
-		if (control->schema != NULL &&
+		if (d_cascade == NULL && control->schema != NULL &&
 			strcmp(control->schema, schemaName) != 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -1351,19 +1370,22 @@ CreateExtension(CreateExtensionStmt *stmt)
 					   control->name,
 					   control->schema)));
 
-		/* If the user is giving us the schema name, it must exist already */
+		/* If the user is giving us the schema name, it must exist already. */
 		schemaOid = get_namespace_oid(schemaName, false);
 	}
-	else if (control->schema != NULL)
+
+	if (control->schema != NULL)
 	{
 		/*
 		 * The extension is not relocatable and the author gave us a schema
 		 * for it.  We create the schema here if it does not already exist.
+		 *
+		 * We already did the validation of user specified schema above.
 		 */
 		schemaName = control->schema;
 		schemaOid = get_namespace_oid(schemaName, true);
 
-		if (schemaOid == InvalidOid)
+		if (!OidIsValid(schemaOid))
 		{
 			CreateSchemaStmt *csstmt = makeNode(CreateSchemaStmt);
 
@@ -1375,16 +1397,17 @@ CreateExtension(CreateExtensionStmt *stmt)
 
 			/*
 			 * CreateSchemaCommand includes CommandCounterIncrement, so new
-			 * schema is now visible
+			 * schema is now visible.
 			 */
 			schemaOid = get_namespace_oid(schemaName, false);
 		}
 	}
-	else
+	else if (!OidIsValid(schemaOid))
 	{
 		/*
-		 * Else, use the current default creation namespace, which is the
-		 * first explicit entry in the search_path.
+		 * Neither user nor author of the extension specified schema, use the
+		 * current default creation namespace, which is the first explicit
+		 * entry in the search_path.
 		 */
 		List	   *search_path = fetch_search_path(false);
 
@@ -1429,10 +1452,60 @@ CreateExtension(CreateExtensionStmt *stmt)
 		 */
 		reqext = get_extension_oid(curreq, true);
 		if (!OidIsValid(reqext))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("required extension \"%s\" is not installed",
-							curreq)));
+		{
+			if (d_cascade)
+			{
+				CreateExtensionStmt *ces;
+				ListCell	   *lc;
+				ObjectAddress	addr;
+
+				ereport(NOTICE,
+						(errmsg("installing required extension \"%s\"",
+								curreq)));
+
+				/* Check for cyclic dependency between extensions. */
+				foreach(lc, cascade_parents)
+				{
+					char	   *pname = (char *) lfirst(lc);
+
+					if (strcmp(pname, curreq) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_RECURSION),
+								 errmsg("cyclic dependency detected between extensions \"%s\" and \"%s\"",
+										curreq, stmt->extname)));
+				}
+
+				/* Create and execute new CREATE EXTENSION statement. */
+				ces = makeNode(CreateExtensionStmt);
+				ces->extname = curreq;
+				ces->if_not_exists = false;
+
+				/*
+				 * Propagate the CASCADE option and add current extension
+				 * to the list for checking the cyclic dependencies.
+				 */
+				cascade_parents = lappend(cascade_parents, stmt->extname);
+				ces->options = list_make1(makeDefElem("cascade",
+													  (Node *) cascade_parents));
+
+				/* Propagate the SCHEMA option if given. */
+				if (d_schema && d_schema->arg)
+					ces->options = lappend(ces->options, d_schema);
+
+				addr = CreateExtension(ces);
+				reqext = addr.objectId;
+
+				/* We leak the DeflElems but probably not worth worrying about */
+				list_free(ces->options);
+				pfree(ces);
+			}
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("required extension \"%s\" is not installed",
+								curreq)));
+		}
+
 		reqschema = get_extension_schema(reqext);
 		requiredExtensions = lappend_oid(requiredExtensions, reqext);
 		requiredSchemas = lappend_oid(requiredSchemas, reqschema);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 6b02cec..4fb5457 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3877,6 +3877,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("old_version", (Node *)makeString($2));
 				}
+			| CASCADE
+				{
+					$$ = makeDefElem("cascade", NULL);
+				}
 		;
 
 /*****************************************************************************
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index ece0515..04da67c 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2247,7 +2247,12 @@ psql_completion(const char *text, int start, int end)
 	/* CREATE EXTENSION <name> */
 	else if (pg_strcasecmp(prev3_wd, "CREATE") == 0 &&
 			 pg_strcasecmp(prev2_wd, "EXTENSION") == 0)
-		COMPLETE_WITH_CONST("WITH SCHEMA");
+	{
+		static const char *const list_CREATE_EXTENSION[] =
+		{"WITH SCHEMA", "CASCADE", NULL};
+
+		COMPLETE_WITH_LIST(list_CREATE_EXTENSION);
+	}
 
 	/* CREATE FOREIGN */
 	else if (pg_strcasecmp(prev2_wd, "CREATE") == 0 &&
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 8213e23..84b4423 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -8,6 +8,7 @@ SUBDIRS = \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \
+		  test_extensions \
 		  test_parser \
 		  test_rls_hooks \
 		  test_shm_mq \
diff --git a/src/test/modules/test_extensions/.gitignore b/src/test/modules/test_extensions/.gitignore
new file mode 100644
index 0000000..5dcb3ff
--- /dev/null
+++ b/src/test/modules/test_extensions/.gitignore
@@ -0,0 +1,4 @@
+# Generated subdirectories
+/log/
+/results/
+/tmp_check/
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
new file mode 100644
index 0000000..6c50e6c
--- /dev/null
+++ b/src/test/modules/test_extensions/Makefile
@@ -0,0 +1,21 @@
+# src/test/modules/test_extensions/Makefile
+
+MODULE = test_extensions
+PGFILEDESC = "test_extensions - regression testing for EXTENSION support"
+
+EXTENSION = test_ext1 test_ext2 test_ext3 test_ext_cyclic1 test_ext_cyclic2
+DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
+	   test_ext_cyclic1--1.0.sql test_ext_cyclic2--1.0.sql
+
+REGRESS = test_extensions
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_extensions
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
new file mode 100644
index 0000000..6cc24e2
--- /dev/null
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -0,0 +1,30 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+ERROR:  required extension "test_ext2" is not installed
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+ERROR:  schema "test_ext1" does not exist
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+NOTICE:  installing required extension "test_ext2"
+NOTICE:  installing required extension "test_ext3"
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+  extname  |  nspname  | extversion | extrelocatable 
+-----------+-----------+------------+----------------
+ test_ext2 | test_ext  | 1.0        | t
+ test_ext3 | test_ext  | 1.0        | t
+ test_ext1 | test_ext1 | 1.0        | f
+(3 rows)
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+NOTICE:  installing required extension "test_ext_cyclic2"
+NOTICE:  installing required extension "test_ext_cyclic1"
+ERROR:  cyclic dependency detected between extensions "test_ext_cyclic1" and "test_ext_cyclic2"
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
new file mode 100644
index 0000000..640ac9b
--- /dev/null
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -0,0 +1,18 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/test_ext1--1.0.sql b/src/test/modules/test_extensions/test_ext1--1.0.sql
new file mode 100644
index 0000000..9a4bb1b
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext1.control b/src/test/modules/test_extensions/test_ext1.control
new file mode 100644
index 0000000..ae50cd8
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1.control
@@ -0,0 +1,5 @@
+comment = 'Test extension 1'
+default_version = '1.0'
+schema = 'test_ext1'
+relocatable = false
+requires = 'test_ext2'
diff --git a/src/test/modules/test_extensions/test_ext2--1.0.sql b/src/test/modules/test_extensions/test_ext2--1.0.sql
new file mode 100644
index 0000000..0f6d4ec
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext2.control b/src/test/modules/test_extensions/test_ext2.control
new file mode 100644
index 0000000..788337e
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext3'
diff --git a/src/test/modules/test_extensions/test_ext3--1.0.sql b/src/test/modules/test_extensions/test_ext3--1.0.sql
new file mode 100644
index 0000000..7dec684
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext3--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext3" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext3.control b/src/test/modules/test_extensions/test_ext3.control
new file mode 100644
index 0000000..5f1afe7
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 3'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
new file mode 100644
index 0000000..81bdaf4
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1.control b/src/test/modules/test_extensions/test_ext_cyclic1.control
new file mode 100644
index 0000000..aaab403
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 1'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic2'
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
new file mode 100644
index 0000000..ae2b3e9
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2.control b/src/test/modules/test_extensions/test_ext_cyclic2.control
new file mode 100644
index 0000000..1e28f96
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic1'
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index d70db40..9b3e31e 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -41,7 +41,7 @@ my $contrib_extrasource = {
 	'seg'  => [ 'contrib/seg/segscan.l',   'contrib/seg/segparse.y' ], };
 my @contrib_excludes = (
 	'commit_ts',      'hstore_plperl', 'hstore_plpython', 'intagg',
-	'ltree_plpython', 'pgcrypto',      'sepgsql');
+	'ltree_plpython', 'pgcrypto',      'sepgsql',         'test_extensions');
 
 # Set of variables for frontend modules
 my $frontend_defines = { 'initdb' => 'FRONTEND' };

From 5fc0c3245d82220deb7adcc3704b95b82893fcfe Mon Sep 17 00:00:00 2001
From: Petr Jelinek <pjmodos@pjmodos.net>
Date: Sat, 13 Jun 2015 19:49:10 +0200
Subject: [PATCH] CREATE EXTENSION CASCADE

---
 contrib/hstore_plperl/expected/hstore_plperl.out   |   6 +-
 contrib/hstore_plperl/expected/hstore_plperlu.out  |   6 +-
 contrib/hstore_plperl/sql/hstore_plperl.sql        |   4 +-
 contrib/hstore_plperl/sql/hstore_plperlu.sql       |   4 +-
 .../hstore_plpython/expected/hstore_plpython.out   |   4 +-
 contrib/hstore_plpython/sql/hstore_plpython.sql    |   3 +-
 contrib/ltree_plpython/expected/ltree_plpython.out |   4 +-
 contrib/ltree_plpython/sql/ltree_plpython.sql      |   3 +-
 doc/src/sgml/ref/create_extension.sgml             |  42 +++++
 src/backend/commands/extension.c                   | 209 +++++++++++++++------
 src/backend/parser/gram.y                          |   4 +
 src/bin/psql/tab-complete.c                        |   7 +-
 src/test/modules/Makefile                          |   1 +
 src/test/modules/test_extensions/.gitignore        |   3 +
 src/test/modules/test_extensions/Makefile          |  21 +++
 .../test_extensions/expected/test_extensions.out   |  30 +++
 .../test_extensions/sql/test_extensions.sql        |  18 ++
 .../modules/test_extensions/test_ext1--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext1.control |   5 +
 .../modules/test_extensions/test_ext2--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext2.control |   4 +
 .../modules/test_extensions/test_ext3--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext3.control |   3 +
 .../test_extensions/test_ext_cyclic1--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic1.control       |   4 +
 .../test_extensions/test_ext_cyclic2--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic2.control       |   4 +
 src/tools/msvc/Mkvcbuild.pm                        |   3 +-
 28 files changed, 323 insertions(+), 84 deletions(-)
 create mode 100644 src/test/modules/test_extensions/.gitignore
 create mode 100644 src/test/modules/test_extensions/Makefile
 create mode 100644 src/test/modules/test_extensions/expected/test_extensions.out
 create mode 100644 src/test/modules/test_extensions/sql/test_extensions.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1.control
 create mode 100644 src/test/modules/test_extensions/test_ext2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext2.control
 create mode 100644 src/test/modules/test_extensions/test_ext3--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext3.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2.control

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index cf384eb..25fc506 100644
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperl"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/expected/hstore_plperlu.out b/contrib/hstore_plperl/expected/hstore_plperlu.out
index 8c689ad..3fc3201 100644
--- a/contrib/hstore_plperl/expected/hstore_plperlu.out
+++ b/contrib/hstore_plperl/expected/hstore_plperlu.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperlu"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 0f70f14..9398aed 100644
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plperl/sql/hstore_plperlu.sql b/contrib/hstore_plperl/sql/hstore_plperlu.sql
index 3cfb2fd..8d8508c 100644
--- a/contrib/hstore_plperl/sql/hstore_plperlu.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperlu.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index b7a6a92..55f4efe 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 -- test hstore -> python
 CREATE FUNCTION test1(val hstore) RETURNS int
 LANGUAGE plpythonu
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index 9ff2ebc..d55beda 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
 
 
 -- test hstore -> python
diff --git a/contrib/ltree_plpython/expected/ltree_plpython.out b/contrib/ltree_plpython/expected/ltree_plpython.out
index 934529e..9bee6be 100644
--- a/contrib/ltree_plpython/expected/ltree_plpython.out
+++ b/contrib/ltree_plpython/expected/ltree_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 CREATE FUNCTION test1(val ltree) RETURNS int
 LANGUAGE plpythonu
 TRANSFORM FOR TYPE ltree
diff --git a/contrib/ltree_plpython/sql/ltree_plpython.sql b/contrib/ltree_plpython/sql/ltree_plpython.sql
index f08ff6a..210f542 100644
--- a/contrib/ltree_plpython/sql/ltree_plpython.sql
+++ b/contrib/ltree_plpython/sql/ltree_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
 
 
 CREATE FUNCTION test1(val ltree) RETURNS int
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index a1e7e4f8..6f4d3f9 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -25,6 +25,7 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
     [ WITH ] [ SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
              [ VERSION <replaceable class="parameter">version</replaceable> ]
              [ FROM <replaceable class="parameter">old_version</replaceable> ]
+             [ CASCADE ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -95,6 +96,36 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         schema either, the current default object creation schema is used.
        </para>
        <para>
+        In case the extension specifies schema in its control file, the schema
+        can't be overriden using <literal>SCHEMA</> parameter. The actual
+        behavior of the <literal>SCHEMA</> parameter in this case will depend
+        on circumstances:
+        <itemizedlist>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> matches
+           the schema in control file, it will be used normally as there is no
+           conflict.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If <literal>CASCADE</> parameter is given, the
+           <replaceable class="parameter">schema_name</replaceable> will only
+           be used for the missing required extensions which do not specify
+           the schema in their control files.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> is not
+           same as the one in extension's control file and the
+           <literal>CASCADE</> parameter is not given, error will be thrown.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+       <para>
         Remember that the extension itself is not considered to be within any
         schema: extensions have unqualified names that must be unique
         database-wide.  But objects belonging to the extension can be within
@@ -139,6 +170,17 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry>
+      <term><literal>CASCADE</></term>
+      <listitem>
+       <para>
+        Try to install extension including the required dependencies
+        recursively. The <literal>SCHEMA</> option will be propagated
+        to the required extensions.
+       </para>
+      </listitem>
+     </varlistentry>
   </variablelist>
  </refsect1>
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 2b1dcd0..d03e11e 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -43,11 +43,13 @@
 #include "catalog/pg_type.h"
 #include "commands/alter.h"
 #include "commands/comment.h"
+#include "commands/defrem.h"
 #include "commands/extension.h"
 #include "commands/schemacmds.h"
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "storage/fd.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -1165,18 +1167,20 @@ find_update_path(List *evi_list,
 }
 
 /*
- * CREATE EXTENSION
+ * CREATE EXTENSION worker
  */
-ObjectAddress
-CreateExtension(CreateExtensionStmt *stmt)
+static ObjectAddress
+CreateExtensionInternal(CreateExtensionStmt *stmt, List *cascade_parents)
 {
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
 	DefElem    *d_old_version = NULL;
+	DefElem	   *d_cascade = NULL;
 	char	   *schemaName;
-	Oid			schemaOid;
+	Oid			schemaOid = InvalidOid;
 	char	   *versionName;
 	char	   *oldVersionName;
+	bool		cascade;
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
@@ -1187,41 +1191,6 @@ CreateExtension(CreateExtensionStmt *stmt)
 	ListCell   *lc;
 	ObjectAddress address;
 
-	/* Check extension name validity before any filesystem access */
-	check_valid_extension_name(stmt->extname);
-
-	/*
-	 * Check for duplicate extension name.  The unique index on
-	 * pg_extension.extname would catch this anyway, and serves as a backstop
-	 * in case of race conditions; but this is a friendlier error message, and
-	 * besides we need a check to support IF NOT EXISTS.
-	 */
-	if (get_extension_oid(stmt->extname, true) != InvalidOid)
-	{
-		if (stmt->if_not_exists)
-		{
-			ereport(NOTICE,
-					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("extension \"%s\" already exists, skipping",
-							stmt->extname)));
-			return InvalidObjectAddress;
-		}
-		else
-			ereport(ERROR,
-					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("extension \"%s\" already exists",
-							stmt->extname)));
-	}
-
-	/*
-	 * We use global variables to track the extension being created, so we can
-	 * create only one extension at the same time.
-	 */
-	if (creating_extension)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("nested CREATE EXTENSION is not supported")));
-
 	/*
 	 * Read the primary control file.  Note we assume that it does not contain
 	 * any non-ASCII data, so there is no need to worry about encoding at this
@@ -1260,6 +1229,14 @@ CreateExtension(CreateExtensionStmt *stmt)
 						 errmsg("conflicting or redundant options")));
 			d_old_version = defel;
 		}
+		else if (strcmp(defel->defname, "cascade") == 0)
+		{
+			if (d_cascade)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_cascade = defel;
+		}
 		else
 			elog(ERROR, "unrecognized option: %s", defel->defname);
 	}
@@ -1330,6 +1307,13 @@ CreateExtension(CreateExtensionStmt *stmt)
 	 */
 	control = read_extension_aux_control_file(pcontrol, versionName);
 
+
+	/* Handle the CASCADE option. */
+	if (d_cascade)
+		cascade = defGetBoolean(d_cascade);
+	else
+		cascade = false;
+
 	/*
 	 * Determine the target schema to install the extension into
 	 */
@@ -1337,33 +1321,36 @@ CreateExtension(CreateExtensionStmt *stmt)
 	{
 		/*
 		 * User given schema, CREATE EXTENSION ... WITH SCHEMA ...
-		 *
-		 * It's an error to give a schema different from control->schema if
-		 * control->schema is specified.
 		 */
 		schemaName = strVal(d_schema->arg);
 
-		if (control->schema != NULL &&
-			strcmp(control->schema, schemaName) != 0)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				errmsg("extension \"%s\" must be installed in schema \"%s\"",
-					   control->name,
-					   control->schema)));
-
-		/* If the user is giving us the schema name, it must exist already */
+		/* If the user is giving us the schema name, it must exist already. */
 		schemaOid = get_namespace_oid(schemaName, false);
 	}
-	else if (control->schema != NULL)
+
+	if (control->schema != NULL)
 	{
 		/*
 		 * The extension is not relocatable and the author gave us a schema
-		 * for it.  We create the schema here if it does not already exist.
+		 * for it.
 		 */
 		schemaName = control->schema;
+
+		/*
+		 * Unless CASCADE parameter was given, it's an error to give a schema
+		 * different from control->schema if control->schema is specified.
+		 */
+		if (!cascade && strcmp(control->schema, schemaName) != 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("extension \"%s\" must be installed in schema \"%s\"",
+					   control->name,
+					   control->schema)));
+
+		/* Find or create the schema in case it does not exist. */
 		schemaOid = get_namespace_oid(schemaName, true);
 
-		if (schemaOid == InvalidOid)
+		if (!OidIsValid(schemaOid))
 		{
 			CreateSchemaStmt *csstmt = makeNode(CreateSchemaStmt);
 
@@ -1375,16 +1362,17 @@ CreateExtension(CreateExtensionStmt *stmt)
 
 			/*
 			 * CreateSchemaCommand includes CommandCounterIncrement, so new
-			 * schema is now visible
+			 * schema is now visible.
 			 */
 			schemaOid = get_namespace_oid(schemaName, false);
 		}
 	}
-	else
+	else if (!OidIsValid(schemaOid))
 	{
 		/*
-		 * Else, use the current default creation namespace, which is the
-		 * first explicit entry in the search_path.
+		 * Neither user nor author of the extension specified schema, use the
+		 * current default creation namespace, which is the first explicit
+		 * entry in the search_path.
 		 */
 		List	   *search_path = fetch_search_path(false);
 
@@ -1429,10 +1417,61 @@ CreateExtension(CreateExtensionStmt *stmt)
 		 */
 		reqext = get_extension_oid(curreq, true);
 		if (!OidIsValid(reqext))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("required extension \"%s\" is not installed",
-							curreq)));
+		{
+			if (cascade)
+			{
+				CreateExtensionStmt *ces;
+				ListCell	   *lc;
+				ObjectAddress	addr;
+
+				/* Check extension name validity before trying to cascade */
+				check_valid_extension_name(curreq);
+
+				ereport(NOTICE,
+						(errmsg("installing required extension \"%s\"",
+								curreq)));
+
+				/* Check for cyclic dependency between extensions. */
+				foreach(lc, cascade_parents)
+				{
+					char	   *pname = (char *) lfirst(lc);
+
+					if (strcmp(pname, curreq) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_RECURSION),
+								 errmsg("cyclic dependency detected between extensions \"%s\" and \"%s\"",
+										curreq, stmt->extname)));
+				}
+
+				/* Create and execute new CREATE EXTENSION statement. */
+				ces = makeNode(CreateExtensionStmt);
+				ces->extname = curreq;
+
+				/*
+				 * Propagate the CASCADE option and add current extension
+				 * to the list for checking the cyclic dependencies.
+				 */
+				ces->options = list_make1(d_cascade);
+				cascade_parents = lappend(cascade_parents, stmt->extname);
+
+				/* Propagate the SCHEMA option if given. */
+				if (d_schema && d_schema->arg)
+					ces->options = lappend(ces->options, d_schema);
+
+				/* Create the required extension. */
+				addr = CreateExtensionInternal(ces, cascade_parents);
+				reqext = addr.objectId;
+
+				list_free(ces->options);
+				pfree(ces);
+			}
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("required extension \"%s\" is not installed",
+								curreq)));
+		}
+
 		reqschema = get_extension_schema(reqext);
 		requiredExtensions = lappend_oid(requiredExtensions, reqext);
 		requiredSchemas = lappend_oid(requiredSchemas, reqschema);
@@ -1474,6 +1513,52 @@ CreateExtension(CreateExtensionStmt *stmt)
 }
 
 /*
+ * CREATE EXTENSION
+ */
+ObjectAddress
+CreateExtension(CreateExtensionStmt *stmt)
+{
+	/* Check extension name validity before any filesystem access */
+	check_valid_extension_name(stmt->extname);
+
+	/*
+	 * Check for duplicate extension name.  The unique index on
+	 * pg_extension.extname would catch this anyway, and serves as a backstop
+	 * in case of race conditions; but this is a friendlier error message, and
+	 * besides we need a check to support IF NOT EXISTS.
+	 */
+	if (get_extension_oid(stmt->extname, true) != InvalidOid)
+	{
+		if (stmt->if_not_exists)
+		{
+			ereport(NOTICE,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("extension \"%s\" already exists, skipping",
+							stmt->extname)));
+			return InvalidObjectAddress;
+		}
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("extension \"%s\" already exists",
+							stmt->extname)));
+	}
+
+	/*
+	 * We use global variables to track the extension being created, so we can
+	 * create only one extension at the same time.
+	 */
+	if (creating_extension)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("nested CREATE EXTENSION is not supported")));
+
+
+	/* Finally create the extension. */
+	return CreateExtensionInternal(stmt, NIL);
+}
+
+/*
  * InsertExtensionTuple
  *
  * Insert the new pg_extension row, and create extension's dependency entries.
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 1efc6d6..b41c610 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3876,6 +3876,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("old_version", (Node *)makeString($2));
 				}
+			| CASCADE
+				{
+					$$ = makeDefElem("cascade", (Node *)makeInteger(TRUE));
+				}
 		;
 
 /*****************************************************************************
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 816deda..5b2d3cf 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2247,7 +2247,12 @@ psql_completion(const char *text, int start, int end)
 	/* CREATE EXTENSION <name> */
 	else if (pg_strcasecmp(prev3_wd, "CREATE") == 0 &&
 			 pg_strcasecmp(prev2_wd, "EXTENSION") == 0)
-		COMPLETE_WITH_CONST("WITH SCHEMA");
+	{
+		static const char *const list_CREATE_EXTENSION[] =
+		{"WITH SCHEMA", "CASCADE", NULL};
+
+		COMPLETE_WITH_LIST(list_CREATE_EXTENSION);
+	}
 
 	/* CREATE FOREIGN */
 	else if (pg_strcasecmp(prev2_wd, "CREATE") == 0 &&
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 9b96654..6167ec1 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -9,6 +9,7 @@ SUBDIRS = \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \
+		  test_extensions \
 		  test_parser \
 		  test_rls_hooks \
 		  test_shm_mq \
diff --git a/src/test/modules/test_extensions/.gitignore b/src/test/modules/test_extensions/.gitignore
new file mode 100644
index 0000000..c08326f
--- /dev/null
+++ b/src/test/modules/test_extensions/.gitignore
@@ -0,0 +1,3 @@
+# Generated subdirectories
+/results/
+/tmp_check/
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
new file mode 100644
index 0000000..6c50e6c
--- /dev/null
+++ b/src/test/modules/test_extensions/Makefile
@@ -0,0 +1,21 @@
+# src/test/modules/test_extensions/Makefile
+
+MODULE = test_extensions
+PGFILEDESC = "test_extensions - regression testing for EXTENSION support"
+
+EXTENSION = test_ext1 test_ext2 test_ext3 test_ext_cyclic1 test_ext_cyclic2
+DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
+	   test_ext_cyclic1--1.0.sql test_ext_cyclic2--1.0.sql
+
+REGRESS = test_extensions
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_extensions
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
new file mode 100644
index 0000000..c90463d
--- /dev/null
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -0,0 +1,30 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+ERROR:  required extension "test_ext2" is not installed
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+ERROR:  schema "test_ext1" does not exist
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  schema "test_ext" does not exist
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  required extension "test_ext2" is not installed
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+NOTICE:  installing required extension "test_ext2"
+NOTICE:  installing required extension "test_ext3"
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+  extname  |  nspname  | extversion | extrelocatable 
+-----------+-----------+------------+----------------
+ test_ext2 | test_ext  | 1.0        | t
+ test_ext3 | test_ext  | 1.0        | t
+ test_ext1 | test_ext1 | 1.0        | f
+(3 rows)
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+NOTICE:  installing required extension "test_ext_cyclic2"
+NOTICE:  installing required extension "test_ext_cyclic1"
+ERROR:  cyclic dependency detected between extensions "test_ext_cyclic1" and "test_ext_cyclic2"
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
new file mode 100644
index 0000000..640ac9b
--- /dev/null
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -0,0 +1,18 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid;
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/test_ext1--1.0.sql b/src/test/modules/test_extensions/test_ext1--1.0.sql
new file mode 100644
index 0000000..9a4bb1b
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext1.control b/src/test/modules/test_extensions/test_ext1.control
new file mode 100644
index 0000000..ae50cd8
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1.control
@@ -0,0 +1,5 @@
+comment = 'Test extension 1'
+default_version = '1.0'
+schema = 'test_ext1'
+relocatable = false
+requires = 'test_ext2'
diff --git a/src/test/modules/test_extensions/test_ext2--1.0.sql b/src/test/modules/test_extensions/test_ext2--1.0.sql
new file mode 100644
index 0000000..0f6d4ec
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext2.control b/src/test/modules/test_extensions/test_ext2.control
new file mode 100644
index 0000000..788337e
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext3'
diff --git a/src/test/modules/test_extensions/test_ext3--1.0.sql b/src/test/modules/test_extensions/test_ext3--1.0.sql
new file mode 100644
index 0000000..7dec684
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext3--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext3" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext3.control b/src/test/modules/test_extensions/test_ext3.control
new file mode 100644
index 0000000..5f1afe7
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 3'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
new file mode 100644
index 0000000..81bdaf4
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1.control b/src/test/modules/test_extensions/test_ext_cyclic1.control
new file mode 100644
index 0000000..aaab403
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 1'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic2'
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
new file mode 100644
index 0000000..ae2b3e9
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2.control b/src/test/modules/test_extensions/test_ext_cyclic2.control
new file mode 100644
index 0000000..1e28f96
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic1'
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 3abbb4c..c122f02 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -41,7 +41,8 @@ my $contrib_extrasource = {
 	'seg'  => [ 'contrib/seg/segscan.l',   'contrib/seg/segparse.y' ], };
 my @contrib_excludes = (
 	'commit_ts',      'hstore_plperl', 'hstore_plpython', 'intagg',
-	'ltree_plpython', 'pgcrypto',      'sepgsql',         'brin');
+	'ltree_plpython', 'pgcrypto',      'sepgsql',         'brin',
+	'test_extensions');
 
 # Set of variables for frontend modules
 my $frontend_defines = { 'initdb' => 'FRONTEND' };
-- 
1.9.1

diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index 6f4d3f9..57bf9f6 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -92,14 +92,14 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         The name of the schema in which to install the extension's
         objects, given that the extension allows its contents to be
         relocated.  The named schema must already exist.
-        If not specified, and the extension's control file does not specify a
-        schema either, the current default object creation schema is used.
+        If not specified, and the extension control file does not define
+        <literal>schema</> either, the current default object creation
+        schema is used.
        </para>
        <para>
-        In case the extension specifies schema in its control file, the schema
-        can't be overriden using <literal>SCHEMA</> parameter. The actual
-        behavior of the <literal>SCHEMA</> parameter in this case will depend
-        on circumstances:
+        If the extension specifies <literal>schema</> in its control file,
+        the schema cannot be overriden with <literal>SCHEMA</> clause.
+        The <literal>SCHEMA</> clause in this case works as follows:
         <itemizedlist>
          <listitem>
           <para>
@@ -110,17 +110,17 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
          </listitem>
          <listitem>
           <para>
-           If <literal>CASCADE</> parameter is given, the
+           If the <literal>CASCADE</> clause is given, the
            <replaceable class="parameter">schema_name</replaceable> will only
            be used for the missing required extensions which do not specify
-           the schema in their control files.
+           <literal>schema</> in their control files.
           </para>
          </listitem>
          <listitem>
           <para>
            If <replaceable class="parameter">schema_name</replaceable> is not
-           same as the one in extension's control file and the
-           <literal>CASCADE</> parameter is not given, error will be thrown.
+           the same as the one in extension's control file and the
+           <literal>CASCADE</> clause is not given, error will be thrown.
           </para>
          </listitem>
         </itemizedlist>
@@ -177,7 +177,8 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        <para>
         Try to install extension including the required dependencies
         recursively. The <literal>SCHEMA</> option will be propagated
-        to the required extensions.
+        to the required extensions.  Other options are not recursively
+        applied when using this clause.
        </para>
       </listitem>
      </varlistentry>

>From ccf995bc4de9cfa45defc5972c91fa77c8593ef2 Mon Sep 17 00:00:00 2001
From: Petr Jelinek <pjmodos@pjmodos.net>
Date: Sat, 13 Jun 2015 19:49:10 +0200
Subject: [PATCH] CREATE EXTENSION CASCADE

---
 contrib/hstore_plperl/expected/hstore_plperl.out   |   6 +-
 contrib/hstore_plperl/expected/hstore_plperlu.out  |   6 +-
 contrib/hstore_plperl/sql/hstore_plperl.sql        |   4 +-
 contrib/hstore_plperl/sql/hstore_plperlu.sql       |   4 +-
 .../hstore_plpython/expected/hstore_plpython.out   |   4 +-
 contrib/hstore_plpython/sql/hstore_plpython.sql    |   3 +-
 contrib/ltree_plpython/expected/ltree_plpython.out |   4 +-
 contrib/ltree_plpython/sql/ltree_plpython.sql      |   3 +-
 doc/src/sgml/ref/create_extension.sgml             |  47 ++++-
 src/backend/commands/extension.c                   | 209 ++++++++++++++-------
 src/backend/parser/gram.y                          |   4 +
 src/bin/psql/tab-complete.c                        |   7 +-
 src/test/modules/Makefile                          |   1 +
 src/test/modules/test_extensions/.gitignore        |   4 +
 src/test/modules/test_extensions/Makefile          |  21 +++
 .../test_extensions/expected/test_extensions.out   |  30 +++
 .../test_extensions/sql/test_extensions.sql        |  18 ++
 .../modules/test_extensions/test_ext1--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext1.control |   5 +
 .../modules/test_extensions/test_ext2--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext2.control |   4 +
 .../modules/test_extensions/test_ext3--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext3.control |   3 +
 .../test_extensions/test_ext_cyclic1--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic1.control       |   4 +
 .../test_extensions/test_ext_cyclic2--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic2.control       |   4 +
 src/tools/msvc/Mkvcbuild.pm                        |   3 +-
 28 files changed, 326 insertions(+), 87 deletions(-)
 create mode 100644 src/test/modules/test_extensions/.gitignore
 create mode 100644 src/test/modules/test_extensions/Makefile
 create mode 100644 src/test/modules/test_extensions/expected/test_extensions.out
 create mode 100644 src/test/modules/test_extensions/sql/test_extensions.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1.control
 create mode 100644 src/test/modules/test_extensions/test_ext2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext2.control
 create mode 100644 src/test/modules/test_extensions/test_ext3--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext3.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2.control

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index cf384eb..25fc506 100644
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperl"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/expected/hstore_plperlu.out b/contrib/hstore_plperl/expected/hstore_plperlu.out
index c97fd3f..b09fb78 100644
--- a/contrib/hstore_plperl/expected/hstore_plperlu.out
+++ b/contrib/hstore_plperl/expected/hstore_plperlu.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperlu"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 0f70f14..9398aed 100644
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plperl/sql/hstore_plperlu.sql b/contrib/hstore_plperl/sql/hstore_plperlu.sql
index 3cfb2fd..8d8508c 100644
--- a/contrib/hstore_plperl/sql/hstore_plperlu.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperlu.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index 23091d3..b0025c0 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 -- test hstore -> python
 CREATE FUNCTION test1(val hstore) RETURNS int
 LANGUAGE plpythonu
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index 9ff2ebc..d55beda 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
 
 
 -- test hstore -> python
diff --git a/contrib/ltree_plpython/expected/ltree_plpython.out b/contrib/ltree_plpython/expected/ltree_plpython.out
index c6e8a7c..4779755 100644
--- a/contrib/ltree_plpython/expected/ltree_plpython.out
+++ b/contrib/ltree_plpython/expected/ltree_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 CREATE FUNCTION test1(val ltree) RETURNS int
 LANGUAGE plpythonu
 TRANSFORM FOR TYPE ltree
diff --git a/contrib/ltree_plpython/sql/ltree_plpython.sql b/contrib/ltree_plpython/sql/ltree_plpython.sql
index f08ff6a..210f542 100644
--- a/contrib/ltree_plpython/sql/ltree_plpython.sql
+++ b/contrib/ltree_plpython/sql/ltree_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
 
 
 CREATE FUNCTION test1(val ltree) RETURNS int
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index a1e7e4f8..57bf9f6 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -25,6 +25,7 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
     [ WITH ] [ SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
              [ VERSION <replaceable class="parameter">version</replaceable> ]
              [ FROM <replaceable class="parameter">old_version</replaceable> ]
+             [ CASCADE ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -91,8 +92,38 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         The name of the schema in which to install the extension's
         objects, given that the extension allows its contents to be
         relocated.  The named schema must already exist.
-        If not specified, and the extension's control file does not specify a
-        schema either, the current default object creation schema is used.
+        If not specified, and the extension control file does not define
+        <literal>schema</> either, the current default object creation
+        schema is used.
+       </para>
+       <para>
+        If the extension specifies <literal>schema</> in its control file,
+        the schema cannot be overriden with <literal>SCHEMA</> clause.
+        The <literal>SCHEMA</> clause in this case works as follows:
+        <itemizedlist>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> matches
+           the schema in control file, it will be used normally as there is no
+           conflict.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If the <literal>CASCADE</> clause is given, the
+           <replaceable class="parameter">schema_name</replaceable> will only
+           be used for the missing required extensions which do not specify
+           <literal>schema</> in their control files.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> is not
+           the same as the one in extension's control file and the
+           <literal>CASCADE</> clause is not given, error will be thrown.
+          </para>
+         </listitem>
+        </itemizedlist>
        </para>
        <para>
         Remember that the extension itself is not considered to be within any
@@ -139,6 +170,18 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry>
+      <term><literal>CASCADE</></term>
+      <listitem>
+       <para>
+        Try to install extension including the required dependencies
+        recursively. The <literal>SCHEMA</> option will be propagated
+        to the required extensions.  Other options are not recursively
+        applied when using this clause.
+       </para>
+      </listitem>
+     </varlistentry>
   </variablelist>
  </refsect1>
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 2b1dcd0..e865aba 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -43,11 +43,13 @@
 #include "catalog/pg_type.h"
 #include "commands/alter.h"
 #include "commands/comment.h"
+#include "commands/defrem.h"
 #include "commands/extension.h"
 #include "commands/schemacmds.h"
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "storage/fd.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -1165,18 +1167,20 @@ find_update_path(List *evi_list,
 }
 
 /*
- * CREATE EXTENSION
+ * CREATE EXTENSION worker
  */
-ObjectAddress
-CreateExtension(CreateExtensionStmt *stmt)
+static ObjectAddress
+CreateExtensionInternal(CreateExtensionStmt *stmt, List *cascade_parents)
 {
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
 	DefElem    *d_old_version = NULL;
-	char	   *schemaName;
-	Oid			schemaOid;
+	DefElem	   *d_cascade = NULL;
+	char	   *schemaName = NULL;
+	Oid			schemaOid = InvalidOid;
 	char	   *versionName;
 	char	   *oldVersionName;
+	bool		cascade = false;
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
@@ -1187,41 +1191,6 @@ CreateExtension(CreateExtensionStmt *stmt)
 	ListCell   *lc;
 	ObjectAddress address;
 
-	/* Check extension name validity before any filesystem access */
-	check_valid_extension_name(stmt->extname);
-
-	/*
-	 * Check for duplicate extension name.  The unique index on
-	 * pg_extension.extname would catch this anyway, and serves as a backstop
-	 * in case of race conditions; but this is a friendlier error message, and
-	 * besides we need a check to support IF NOT EXISTS.
-	 */
-	if (get_extension_oid(stmt->extname, true) != InvalidOid)
-	{
-		if (stmt->if_not_exists)
-		{
-			ereport(NOTICE,
-					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("extension \"%s\" already exists, skipping",
-							stmt->extname)));
-			return InvalidObjectAddress;
-		}
-		else
-			ereport(ERROR,
-					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("extension \"%s\" already exists",
-							stmt->extname)));
-	}
-
-	/*
-	 * We use global variables to track the extension being created, so we can
-	 * create only one extension at the same time.
-	 */
-	if (creating_extension)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("nested CREATE EXTENSION is not supported")));
-
 	/*
 	 * Read the primary control file.  Note we assume that it does not contain
 	 * any non-ASCII data, so there is no need to worry about encoding at this
@@ -1260,6 +1229,14 @@ CreateExtension(CreateExtensionStmt *stmt)
 						 errmsg("conflicting or redundant options")));
 			d_old_version = defel;
 		}
+		else if (strcmp(defel->defname, "cascade") == 0)
+		{
+			if (d_cascade)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_cascade = defel;
+		}
 		else
 			elog(ERROR, "unrecognized option: %s", defel->defname);
 	}
@@ -1330,6 +1307,11 @@ CreateExtension(CreateExtensionStmt *stmt)
 	 */
 	control = read_extension_aux_control_file(pcontrol, versionName);
 
+
+	/* Handle the CASCADE option. */
+	if (d_cascade)
+		cascade = defGetBoolean(d_cascade);
+
 	/*
 	 * Determine the target schema to install the extension into
 	 */
@@ -1337,33 +1319,36 @@ CreateExtension(CreateExtensionStmt *stmt)
 	{
 		/*
 		 * User given schema, CREATE EXTENSION ... WITH SCHEMA ...
-		 *
-		 * It's an error to give a schema different from control->schema if
-		 * control->schema is specified.
 		 */
 		schemaName = strVal(d_schema->arg);
 
-		if (control->schema != NULL &&
-			strcmp(control->schema, schemaName) != 0)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				errmsg("extension \"%s\" must be installed in schema \"%s\"",
-					   control->name,
-					   control->schema)));
-
-		/* If the user is giving us the schema name, it must exist already */
+		/* If the user is giving us the schema name, it must exist already. */
 		schemaOid = get_namespace_oid(schemaName, false);
 	}
-	else if (control->schema != NULL)
+
+	if (control->schema != NULL)
 	{
 		/*
 		 * The extension is not relocatable and the author gave us a schema
-		 * for it.  We create the schema here if it does not already exist.
+		 * for it.
+		 *
+		 * Unless CASCADE parameter was given, it's an error to give a schema
+		 * different from control->schema if control->schema is specified.
 		 */
+		if (!cascade && schemaName && strcmp(control->schema, schemaName) != 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("extension \"%s\" must be installed in schema \"%s\"",
+					   control->name,
+					   control->schema)));
+
+		/* Always use the schema from control file for current extension. */
 		schemaName = control->schema;
+
+		/* Find or create the schema in case it does not exist. */
 		schemaOid = get_namespace_oid(schemaName, true);
 
-		if (schemaOid == InvalidOid)
+		if (!OidIsValid(schemaOid))
 		{
 			CreateSchemaStmt *csstmt = makeNode(CreateSchemaStmt);
 
@@ -1375,16 +1360,17 @@ CreateExtension(CreateExtensionStmt *stmt)
 
 			/*
 			 * CreateSchemaCommand includes CommandCounterIncrement, so new
-			 * schema is now visible
+			 * schema is now visible.
 			 */
 			schemaOid = get_namespace_oid(schemaName, false);
 		}
 	}
-	else
+	else if (!OidIsValid(schemaOid))
 	{
 		/*
-		 * Else, use the current default creation namespace, which is the
-		 * first explicit entry in the search_path.
+		 * Neither user nor author of the extension specified schema, use the
+		 * current default creation namespace, which is the first explicit
+		 * entry in the search_path.
 		 */
 		List	   *search_path = fetch_search_path(false);
 
@@ -1429,10 +1415,61 @@ CreateExtension(CreateExtensionStmt *stmt)
 		 */
 		reqext = get_extension_oid(curreq, true);
 		if (!OidIsValid(reqext))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("required extension \"%s\" is not installed",
-							curreq)));
+		{
+			if (cascade)
+			{
+				CreateExtensionStmt *ces;
+				ListCell	   *lc;
+				ObjectAddress	addr;
+
+				/* Check extension name validity before trying to cascade */
+				check_valid_extension_name(curreq);
+
+				ereport(NOTICE,
+						(errmsg("installing required extension \"%s\"",
+								curreq)));
+
+				/* Check for cyclic dependency between extensions. */
+				foreach(lc, cascade_parents)
+				{
+					char	   *pname = (char *) lfirst(lc);
+
+					if (strcmp(pname, curreq) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_RECURSION),
+								 errmsg("cyclic dependency detected between extensions \"%s\" and \"%s\"",
+										curreq, stmt->extname)));
+				}
+
+				/* Create and execute new CREATE EXTENSION statement. */
+				ces = makeNode(CreateExtensionStmt);
+				ces->extname = curreq;
+
+				/*
+				 * Propagate the CASCADE option and add current extension
+				 * to the list for checking the cyclic dependencies.
+				 */
+				ces->options = list_make1(d_cascade);
+				cascade_parents = lappend(cascade_parents, stmt->extname);
+
+				/* Propagate the SCHEMA option if given. */
+				if (d_schema && d_schema->arg)
+					ces->options = lappend(ces->options, d_schema);
+
+				/* Create the required extension. */
+				addr = CreateExtensionInternal(ces, cascade_parents);
+				reqext = addr.objectId;
+
+				list_free(ces->options);
+				pfree(ces);
+			}
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("required extension \"%s\" is not installed",
+								curreq)));
+		}
+
 		reqschema = get_extension_schema(reqext);
 		requiredExtensions = lappend_oid(requiredExtensions, reqext);
 		requiredSchemas = lappend_oid(requiredSchemas, reqschema);
@@ -1474,6 +1511,52 @@ CreateExtension(CreateExtensionStmt *stmt)
 }
 
 /*
+ * CREATE EXTENSION
+ */
+ObjectAddress
+CreateExtension(CreateExtensionStmt *stmt)
+{
+	/* Check extension name validity before any filesystem access */
+	check_valid_extension_name(stmt->extname);
+
+	/*
+	 * Check for duplicate extension name.  The unique index on
+	 * pg_extension.extname would catch this anyway, and serves as a backstop
+	 * in case of race conditions; but this is a friendlier error message, and
+	 * besides we need a check to support IF NOT EXISTS.
+	 */
+	if (get_extension_oid(stmt->extname, true) != InvalidOid)
+	{
+		if (stmt->if_not_exists)
+		{
+			ereport(NOTICE,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("extension \"%s\" already exists, skipping",
+							stmt->extname)));
+			return InvalidObjectAddress;
+		}
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("extension \"%s\" already exists",
+							stmt->extname)));
+	}
+
+	/*
+	 * We use global variables to track the extension being created, so we can
+	 * create only one extension at the same time.
+	 */
+	if (creating_extension)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("nested CREATE EXTENSION is not supported")));
+
+
+	/* Finally create the extension. */
+	return CreateExtensionInternal(stmt, NIL);
+}
+
+/*
  * InsertExtensionTuple
  *
  * Insert the new pg_extension row, and create extension's dependency entries.
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 1efc6d6..b41c610 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3876,6 +3876,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("old_version", (Node *)makeString($2));
 				}
+			| CASCADE
+				{
+					$$ = makeDefElem("cascade", (Node *)makeInteger(TRUE));
+				}
 		;
 
 /*****************************************************************************
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 0cb3464..ab121f8 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2264,7 +2264,12 @@ psql_completion(const char *text, int start, int end)
 	/* CREATE EXTENSION <name> */
 	else if (pg_strcasecmp(prev3_wd, "CREATE") == 0 &&
 			 pg_strcasecmp(prev2_wd, "EXTENSION") == 0)
-		COMPLETE_WITH_CONST("WITH SCHEMA");
+	{
+		static const char *const list_CREATE_EXTENSION[] =
+		{"WITH SCHEMA", "CASCADE", NULL};
+
+		COMPLETE_WITH_LIST(list_CREATE_EXTENSION);
+	}
 
 	/* CREATE FOREIGN */
 	else if (pg_strcasecmp(prev2_wd, "CREATE") == 0 &&
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 9b96654..6167ec1 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -9,6 +9,7 @@ SUBDIRS = \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \
+		  test_extensions \
 		  test_parser \
 		  test_rls_hooks \
 		  test_shm_mq \
diff --git a/src/test/modules/test_extensions/.gitignore b/src/test/modules/test_extensions/.gitignore
new file mode 100644
index 0000000..5dcb3ff
--- /dev/null
+++ b/src/test/modules/test_extensions/.gitignore
@@ -0,0 +1,4 @@
+# Generated subdirectories
+/log/
+/results/
+/tmp_check/
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
new file mode 100644
index 0000000..6c50e6c
--- /dev/null
+++ b/src/test/modules/test_extensions/Makefile
@@ -0,0 +1,21 @@
+# src/test/modules/test_extensions/Makefile
+
+MODULE = test_extensions
+PGFILEDESC = "test_extensions - regression testing for EXTENSION support"
+
+EXTENSION = test_ext1 test_ext2 test_ext3 test_ext_cyclic1 test_ext_cyclic2
+DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
+	   test_ext_cyclic1--1.0.sql test_ext_cyclic2--1.0.sql
+
+REGRESS = test_extensions
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_extensions
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
new file mode 100644
index 0000000..69a9596
--- /dev/null
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -0,0 +1,30 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+ERROR:  required extension "test_ext2" is not installed
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+ERROR:  schema "test_ext1" does not exist
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  schema "test_ext" does not exist
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+NOTICE:  installing required extension "test_ext2"
+NOTICE:  installing required extension "test_ext3"
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid ORDER BY 1;
+  extname  |  nspname  | extversion | extrelocatable 
+-----------+-----------+------------+----------------
+ test_ext1 | test_ext1 | 1.0        | f
+ test_ext2 | test_ext  | 1.0        | t
+ test_ext3 | test_ext  | 1.0        | t
+(3 rows)
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+NOTICE:  installing required extension "test_ext_cyclic2"
+NOTICE:  installing required extension "test_ext_cyclic1"
+ERROR:  cyclic dependency detected between extensions "test_ext_cyclic1" and "test_ext_cyclic2"
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
new file mode 100644
index 0000000..04c110a
--- /dev/null
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -0,0 +1,18 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid ORDER BY 1;
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/test_ext1--1.0.sql b/src/test/modules/test_extensions/test_ext1--1.0.sql
new file mode 100644
index 0000000..9a4bb1b
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext1.control b/src/test/modules/test_extensions/test_ext1.control
new file mode 100644
index 0000000..ae50cd8
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1.control
@@ -0,0 +1,5 @@
+comment = 'Test extension 1'
+default_version = '1.0'
+schema = 'test_ext1'
+relocatable = false
+requires = 'test_ext2'
diff --git a/src/test/modules/test_extensions/test_ext2--1.0.sql b/src/test/modules/test_extensions/test_ext2--1.0.sql
new file mode 100644
index 0000000..0f6d4ec
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext2.control b/src/test/modules/test_extensions/test_ext2.control
new file mode 100644
index 0000000..788337e
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext3'
diff --git a/src/test/modules/test_extensions/test_ext3--1.0.sql b/src/test/modules/test_extensions/test_ext3--1.0.sql
new file mode 100644
index 0000000..7dec684
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext3--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext3" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext3.control b/src/test/modules/test_extensions/test_ext3.control
new file mode 100644
index 0000000..5f1afe7
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 3'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
new file mode 100644
index 0000000..81bdaf4
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1.control b/src/test/modules/test_extensions/test_ext_cyclic1.control
new file mode 100644
index 0000000..aaab403
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 1'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic2'
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
new file mode 100644
index 0000000..ae2b3e9
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2.control b/src/test/modules/test_extensions/test_ext_cyclic2.control
new file mode 100644
index 0000000..1e28f96
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic1'
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 3abbb4c..c122f02 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -41,7 +41,8 @@ my $contrib_extrasource = {
 	'seg'  => [ 'contrib/seg/segscan.l',   'contrib/seg/segparse.y' ], };
 my @contrib_excludes = (
 	'commit_ts',      'hstore_plperl', 'hstore_plpython', 'intagg',
-	'ltree_plpython', 'pgcrypto',      'sepgsql',         'brin');
+	'ltree_plpython', 'pgcrypto',      'sepgsql',         'brin',
+	'test_extensions');
 
 # Set of variables for frontend modules
 my $frontend_defines = { 'initdb' => 'FRONTEND' };
-- 
1.9.1

>From a6cc566f4d8600398d6dde1ab478b1565fe9871b Mon Sep 17 00:00:00 2001
From: Petr Jelinek <pjmodos@pjmodos.net>
Date: Sat, 13 Jun 2015 19:49:10 +0200
Subject: [PATCH] CREATE EXTENSION CASCADE

---
 contrib/hstore_plperl/expected/hstore_plperl.out   |   6 +-
 contrib/hstore_plperl/expected/hstore_plperlu.out  |   6 +-
 contrib/hstore_plperl/sql/hstore_plperl.sql        |   4 +-
 contrib/hstore_plperl/sql/hstore_plperlu.sql       |   4 +-
 .../hstore_plpython/expected/hstore_plpython.out   |   4 +-
 contrib/hstore_plpython/sql/hstore_plpython.sql    |   3 +-
 contrib/ltree_plpython/expected/ltree_plpython.out |   4 +-
 contrib/ltree_plpython/sql/ltree_plpython.sql      |   3 +-
 doc/src/sgml/ref/create_extension.sgml             |  47 ++++-
 src/backend/commands/extension.c                   | 210 ++++++++++++++-------
 src/backend/parser/gram.y                          |   4 +
 src/bin/psql/tab-complete.c                        |   7 +-
 src/test/modules/Makefile                          |   1 +
 src/test/modules/test_extensions/.gitignore        |   4 +
 src/test/modules/test_extensions/Makefile          |  21 +++
 .../test_extensions/expected/test_extensions.out   |  31 +++
 .../test_extensions/sql/test_extensions.sql        |  18 ++
 .../modules/test_extensions/test_ext1--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext1.control |   5 +
 .../modules/test_extensions/test_ext2--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext2.control |   4 +
 .../modules/test_extensions/test_ext3--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext3.control |   3 +
 .../test_extensions/test_ext_cyclic1--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic1.control       |   4 +
 .../test_extensions/test_ext_cyclic2--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic2.control       |   4 +
 src/tools/msvc/Mkvcbuild.pm                        |   3 +-
 28 files changed, 328 insertions(+), 87 deletions(-)
 create mode 100644 src/test/modules/test_extensions/.gitignore
 create mode 100644 src/test/modules/test_extensions/Makefile
 create mode 100644 src/test/modules/test_extensions/expected/test_extensions.out
 create mode 100644 src/test/modules/test_extensions/sql/test_extensions.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1.control
 create mode 100644 src/test/modules/test_extensions/test_ext2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext2.control
 create mode 100644 src/test/modules/test_extensions/test_ext3--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext3.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2.control

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index cf384eb..25fc506 100644
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperl"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/expected/hstore_plperlu.out b/contrib/hstore_plperl/expected/hstore_plperlu.out
index c97fd3f..b09fb78 100644
--- a/contrib/hstore_plperl/expected/hstore_plperlu.out
+++ b/contrib/hstore_plperl/expected/hstore_plperlu.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperlu"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 0f70f14..9398aed 100644
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plperl/sql/hstore_plperlu.sql b/contrib/hstore_plperl/sql/hstore_plperlu.sql
index 3cfb2fd..8d8508c 100644
--- a/contrib/hstore_plperl/sql/hstore_plperlu.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperlu.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index 23091d3..b0025c0 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 -- test hstore -> python
 CREATE FUNCTION test1(val hstore) RETURNS int
 LANGUAGE plpythonu
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index 9ff2ebc..d55beda 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
 
 
 -- test hstore -> python
diff --git a/contrib/ltree_plpython/expected/ltree_plpython.out b/contrib/ltree_plpython/expected/ltree_plpython.out
index c6e8a7c..4779755 100644
--- a/contrib/ltree_plpython/expected/ltree_plpython.out
+++ b/contrib/ltree_plpython/expected/ltree_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 CREATE FUNCTION test1(val ltree) RETURNS int
 LANGUAGE plpythonu
 TRANSFORM FOR TYPE ltree
diff --git a/contrib/ltree_plpython/sql/ltree_plpython.sql b/contrib/ltree_plpython/sql/ltree_plpython.sql
index f08ff6a..210f542 100644
--- a/contrib/ltree_plpython/sql/ltree_plpython.sql
+++ b/contrib/ltree_plpython/sql/ltree_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
 
 
 CREATE FUNCTION test1(val ltree) RETURNS int
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index a1e7e4f8..57bf9f6 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -25,6 +25,7 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
     [ WITH ] [ SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
              [ VERSION <replaceable class="parameter">version</replaceable> ]
              [ FROM <replaceable class="parameter">old_version</replaceable> ]
+             [ CASCADE ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -91,8 +92,38 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         The name of the schema in which to install the extension's
         objects, given that the extension allows its contents to be
         relocated.  The named schema must already exist.
-        If not specified, and the extension's control file does not specify a
-        schema either, the current default object creation schema is used.
+        If not specified, and the extension control file does not define
+        <literal>schema</> either, the current default object creation
+        schema is used.
+       </para>
+       <para>
+        If the extension specifies <literal>schema</> in its control file,
+        the schema cannot be overriden with <literal>SCHEMA</> clause.
+        The <literal>SCHEMA</> clause in this case works as follows:
+        <itemizedlist>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> matches
+           the schema in control file, it will be used normally as there is no
+           conflict.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If the <literal>CASCADE</> clause is given, the
+           <replaceable class="parameter">schema_name</replaceable> will only
+           be used for the missing required extensions which do not specify
+           <literal>schema</> in their control files.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> is not
+           the same as the one in extension's control file and the
+           <literal>CASCADE</> clause is not given, error will be thrown.
+          </para>
+         </listitem>
+        </itemizedlist>
        </para>
        <para>
         Remember that the extension itself is not considered to be within any
@@ -139,6 +170,18 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry>
+      <term><literal>CASCADE</></term>
+      <listitem>
+       <para>
+        Try to install extension including the required dependencies
+        recursively. The <literal>SCHEMA</> option will be propagated
+        to the required extensions.  Other options are not recursively
+        applied when using this clause.
+       </para>
+      </listitem>
+     </varlistentry>
   </variablelist>
  </refsect1>
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 6b92bdc..293286a 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -43,11 +43,13 @@
 #include "catalog/pg_type.h"
 #include "commands/alter.h"
 #include "commands/comment.h"
+#include "commands/defrem.h"
 #include "commands/extension.h"
 #include "commands/schemacmds.h"
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "storage/fd.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -1165,18 +1167,20 @@ find_update_path(List *evi_list,
 }
 
 /*
- * CREATE EXTENSION
+ * CREATE EXTENSION worker
  */
-ObjectAddress
-CreateExtension(CreateExtensionStmt *stmt)
+static ObjectAddress
+CreateExtensionInternal(CreateExtensionStmt *stmt, List *cascade_parents)
 {
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
 	DefElem    *d_old_version = NULL;
-	char	   *schemaName;
-	Oid			schemaOid;
+	DefElem	   *d_cascade = NULL;
+	char	   *schemaName = NULL;
+	Oid			schemaOid = InvalidOid;
 	char	   *versionName;
 	char	   *oldVersionName;
+	bool		cascade = false;
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
@@ -1187,41 +1191,6 @@ CreateExtension(CreateExtensionStmt *stmt)
 	ListCell   *lc;
 	ObjectAddress address;
 
-	/* Check extension name validity before any filesystem access */
-	check_valid_extension_name(stmt->extname);
-
-	/*
-	 * Check for duplicate extension name.  The unique index on
-	 * pg_extension.extname would catch this anyway, and serves as a backstop
-	 * in case of race conditions; but this is a friendlier error message, and
-	 * besides we need a check to support IF NOT EXISTS.
-	 */
-	if (get_extension_oid(stmt->extname, true) != InvalidOid)
-	{
-		if (stmt->if_not_exists)
-		{
-			ereport(NOTICE,
-					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("extension \"%s\" already exists, skipping",
-							stmt->extname)));
-			return InvalidObjectAddress;
-		}
-		else
-			ereport(ERROR,
-					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("extension \"%s\" already exists",
-							stmt->extname)));
-	}
-
-	/*
-	 * We use global variables to track the extension being created, so we can
-	 * create only one extension at the same time.
-	 */
-	if (creating_extension)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("nested CREATE EXTENSION is not supported")));
-
 	/*
 	 * Read the primary control file.  Note we assume that it does not contain
 	 * any non-ASCII data, so there is no need to worry about encoding at this
@@ -1260,6 +1229,14 @@ CreateExtension(CreateExtensionStmt *stmt)
 						 errmsg("conflicting or redundant options")));
 			d_old_version = defel;
 		}
+		else if (strcmp(defel->defname, "cascade") == 0)
+		{
+			if (d_cascade)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_cascade = defel;
+		}
 		else
 			elog(ERROR, "unrecognized option: %s", defel->defname);
 	}
@@ -1330,6 +1307,11 @@ CreateExtension(CreateExtensionStmt *stmt)
 	 */
 	control = read_extension_aux_control_file(pcontrol, versionName);
 
+
+	/* Handle the CASCADE option. */
+	if (d_cascade)
+		cascade = defGetBoolean(d_cascade);
+
 	/*
 	 * Determine the target schema to install the extension into
 	 */
@@ -1337,33 +1319,36 @@ CreateExtension(CreateExtensionStmt *stmt)
 	{
 		/*
 		 * User given schema, CREATE EXTENSION ... WITH SCHEMA ...
-		 *
-		 * It's an error to give a schema different from control->schema if
-		 * control->schema is specified.
 		 */
 		schemaName = strVal(d_schema->arg);
 
-		if (control->schema != NULL &&
-			strcmp(control->schema, schemaName) != 0)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				errmsg("extension \"%s\" must be installed in schema \"%s\"",
-					   control->name,
-					   control->schema)));
-
-		/* If the user is giving us the schema name, it must exist already */
+		/* If the user is giving us the schema name, it must exist already. */
 		schemaOid = get_namespace_oid(schemaName, false);
 	}
-	else if (control->schema != NULL)
+
+	if (control->schema != NULL)
 	{
 		/*
 		 * The extension is not relocatable and the author gave us a schema
-		 * for it.  We create the schema here if it does not already exist.
+		 * for it.
+		 *
+		 * Unless CASCADE parameter was given, it's an error to give a schema
+		 * different from control->schema if control->schema is specified.
 		 */
+		if (!cascade && schemaName && strcmp(control->schema, schemaName) != 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("extension \"%s\" must be installed in schema \"%s\"",
+					   control->name,
+					   control->schema)));
+
+		/* Always use the schema from control file for current extension. */
 		schemaName = control->schema;
+
+		/* Find or create the schema in case it does not exist. */
 		schemaOid = get_namespace_oid(schemaName, true);
 
-		if (schemaOid == InvalidOid)
+		if (!OidIsValid(schemaOid))
 		{
 			CreateSchemaStmt *csstmt = makeNode(CreateSchemaStmt);
 
@@ -1375,16 +1360,17 @@ CreateExtension(CreateExtensionStmt *stmt)
 
 			/*
 			 * CreateSchemaCommand includes CommandCounterIncrement, so new
-			 * schema is now visible
+			 * schema is now visible.
 			 */
 			schemaOid = get_namespace_oid(schemaName, false);
 		}
 	}
-	else
+	else if (!OidIsValid(schemaOid))
 	{
 		/*
-		 * Else, use the current default creation namespace, which is the
-		 * first explicit entry in the search_path.
+		 * Neither user nor author of the extension specified schema, use the
+		 * current default creation namespace, which is the first explicit
+		 * entry in the search_path.
 		 */
 		List	   *search_path = fetch_search_path(false);
 
@@ -1429,10 +1415,62 @@ CreateExtension(CreateExtensionStmt *stmt)
 		 */
 		reqext = get_extension_oid(curreq, true);
 		if (!OidIsValid(reqext))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("required extension \"%s\" is not installed",
-							curreq)));
+		{
+			if (cascade)
+			{
+				CreateExtensionStmt *ces;
+				ListCell	   *lc;
+				ObjectAddress	addr;
+
+				/* Check extension name validity before trying to cascade */
+				check_valid_extension_name(curreq);
+
+				ereport(NOTICE,
+						(errmsg("installing required extension \"%s\"",
+								curreq)));
+
+				/* Check for cyclic dependency between extensions. */
+				foreach(lc, cascade_parents)
+				{
+					char	   *pname = (char *) lfirst(lc);
+
+					if (strcmp(pname, curreq) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_RECURSION),
+								 errmsg("cyclic dependency detected between extensions \"%s\" and \"%s\"",
+										curreq, stmt->extname)));
+				}
+
+				/* Create and execute new CREATE EXTENSION statement. */
+				ces = makeNode(CreateExtensionStmt);
+				ces->extname = curreq;
+
+				/*
+				 * Propagate the CASCADE option and add current extension
+				 * to the list for checking the cyclic dependencies.
+				 */
+				ces->options = list_make1(d_cascade);
+				cascade_parents = lappend(cascade_parents, stmt->extname);
+
+				/* Propagate the SCHEMA option if given. */
+				if (d_schema && d_schema->arg)
+					ces->options = lappend(ces->options, d_schema);
+
+				/* Create the required extension. */
+				addr = CreateExtensionInternal(ces, cascade_parents);
+				reqext = addr.objectId;
+
+				list_free(ces->options);
+				pfree(ces);
+			}
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("required extension \"%s\" is not installed",
+								curreq),
+						 errhint("Use CREATE EXTENSION CASCADE to install required extensions too.")));
+		}
+
 		reqschema = get_extension_schema(reqext);
 		requiredExtensions = lappend_oid(requiredExtensions, reqext);
 		requiredSchemas = lappend_oid(requiredSchemas, reqschema);
@@ -1474,6 +1512,52 @@ CreateExtension(CreateExtensionStmt *stmt)
 }
 
 /*
+ * CREATE EXTENSION
+ */
+ObjectAddress
+CreateExtension(CreateExtensionStmt *stmt)
+{
+	/* Check extension name validity before any filesystem access */
+	check_valid_extension_name(stmt->extname);
+
+	/*
+	 * Check for duplicate extension name.  The unique index on
+	 * pg_extension.extname would catch this anyway, and serves as a backstop
+	 * in case of race conditions; but this is a friendlier error message, and
+	 * besides we need a check to support IF NOT EXISTS.
+	 */
+	if (get_extension_oid(stmt->extname, true) != InvalidOid)
+	{
+		if (stmt->if_not_exists)
+		{
+			ereport(NOTICE,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("extension \"%s\" already exists, skipping",
+							stmt->extname)));
+			return InvalidObjectAddress;
+		}
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("extension \"%s\" already exists",
+							stmt->extname)));
+	}
+
+	/*
+	 * We use global variables to track the extension being created, so we can
+	 * create only one extension at the same time.
+	 */
+	if (creating_extension)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("nested CREATE EXTENSION is not supported")));
+
+
+	/* Finally create the extension. */
+	return CreateExtensionInternal(stmt, NIL);
+}
+
+/*
  * InsertExtensionTuple
  *
  * Insert the new pg_extension row, and create extension's dependency entries.
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index fb84937..417fb55 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3876,6 +3876,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("old_version", (Node *)makeString($2));
 				}
+			| CASCADE
+				{
+					$$ = makeDefElem("cascade", (Node *)makeInteger(TRUE));
+				}
 		;
 
 /*****************************************************************************
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 0cb3464..ab121f8 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2264,7 +2264,12 @@ psql_completion(const char *text, int start, int end)
 	/* CREATE EXTENSION <name> */
 	else if (pg_strcasecmp(prev3_wd, "CREATE") == 0 &&
 			 pg_strcasecmp(prev2_wd, "EXTENSION") == 0)
-		COMPLETE_WITH_CONST("WITH SCHEMA");
+	{
+		static const char *const list_CREATE_EXTENSION[] =
+		{"WITH SCHEMA", "CASCADE", NULL};
+
+		COMPLETE_WITH_LIST(list_CREATE_EXTENSION);
+	}
 
 	/* CREATE FOREIGN */
 	else if (pg_strcasecmp(prev2_wd, "CREATE") == 0 &&
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 9b96654..6167ec1 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -9,6 +9,7 @@ SUBDIRS = \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \
+		  test_extensions \
 		  test_parser \
 		  test_rls_hooks \
 		  test_shm_mq \
diff --git a/src/test/modules/test_extensions/.gitignore b/src/test/modules/test_extensions/.gitignore
new file mode 100644
index 0000000..5dcb3ff
--- /dev/null
+++ b/src/test/modules/test_extensions/.gitignore
@@ -0,0 +1,4 @@
+# Generated subdirectories
+/log/
+/results/
+/tmp_check/
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
new file mode 100644
index 0000000..6c50e6c
--- /dev/null
+++ b/src/test/modules/test_extensions/Makefile
@@ -0,0 +1,21 @@
+# src/test/modules/test_extensions/Makefile
+
+MODULE = test_extensions
+PGFILEDESC = "test_extensions - regression testing for EXTENSION support"
+
+EXTENSION = test_ext1 test_ext2 test_ext3 test_ext_cyclic1 test_ext_cyclic2
+DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
+	   test_ext_cyclic1--1.0.sql test_ext_cyclic2--1.0.sql
+
+REGRESS = test_extensions
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_extensions
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
new file mode 100644
index 0000000..b20321a
--- /dev/null
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -0,0 +1,31 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+ERROR:  required extension "test_ext2" is not installed
+HINT:  Use CREATE EXTENSION CASCADE to install required extensions too.
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+ERROR:  schema "test_ext1" does not exist
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  schema "test_ext" does not exist
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+NOTICE:  installing required extension "test_ext2"
+NOTICE:  installing required extension "test_ext3"
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid ORDER BY 1;
+  extname  |  nspname  | extversion | extrelocatable 
+-----------+-----------+------------+----------------
+ test_ext1 | test_ext1 | 1.0        | f
+ test_ext2 | test_ext  | 1.0        | t
+ test_ext3 | test_ext  | 1.0        | t
+(3 rows)
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+NOTICE:  installing required extension "test_ext_cyclic2"
+NOTICE:  installing required extension "test_ext_cyclic1"
+ERROR:  cyclic dependency detected between extensions "test_ext_cyclic1" and "test_ext_cyclic2"
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
new file mode 100644
index 0000000..04c110a
--- /dev/null
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -0,0 +1,18 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid ORDER BY 1;
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/test_ext1--1.0.sql b/src/test/modules/test_extensions/test_ext1--1.0.sql
new file mode 100644
index 0000000..9a4bb1b
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext1.control b/src/test/modules/test_extensions/test_ext1.control
new file mode 100644
index 0000000..ae50cd8
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1.control
@@ -0,0 +1,5 @@
+comment = 'Test extension 1'
+default_version = '1.0'
+schema = 'test_ext1'
+relocatable = false
+requires = 'test_ext2'
diff --git a/src/test/modules/test_extensions/test_ext2--1.0.sql b/src/test/modules/test_extensions/test_ext2--1.0.sql
new file mode 100644
index 0000000..0f6d4ec
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext2.control b/src/test/modules/test_extensions/test_ext2.control
new file mode 100644
index 0000000..788337e
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext3'
diff --git a/src/test/modules/test_extensions/test_ext3--1.0.sql b/src/test/modules/test_extensions/test_ext3--1.0.sql
new file mode 100644
index 0000000..7dec684
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext3--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext3" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext3.control b/src/test/modules/test_extensions/test_ext3.control
new file mode 100644
index 0000000..5f1afe7
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 3'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
new file mode 100644
index 0000000..81bdaf4
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1.control b/src/test/modules/test_extensions/test_ext_cyclic1.control
new file mode 100644
index 0000000..aaab403
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 1'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic2'
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
new file mode 100644
index 0000000..ae2b3e9
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2.control b/src/test/modules/test_extensions/test_ext_cyclic2.control
new file mode 100644
index 0000000..1e28f96
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic1'
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 3abbb4c..c122f02 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -41,7 +41,8 @@ my $contrib_extrasource = {
 	'seg'  => [ 'contrib/seg/segscan.l',   'contrib/seg/segparse.y' ], };
 my @contrib_excludes = (
 	'commit_ts',      'hstore_plperl', 'hstore_plpython', 'intagg',
-	'ltree_plpython', 'pgcrypto',      'sepgsql',         'brin');
+	'ltree_plpython', 'pgcrypto',      'sepgsql',         'brin',
+	'test_extensions');
 
 # Set of variables for frontend modules
 my $frontend_defines = { 'initdb' => 'FRONTEND' };
-- 
1.9.1

>From fa11dc75500eb91b68baeeb07a00a789ed0050b3 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Sat, 3 Oct 2015 17:01:32 +0200
Subject: [PATCH] Add CASCADE support for CREATE EXTENSION.

Without CASCADE, if an extension has an unfullfilled dependency on
another extension, CREATE EXTENSION ERRORs out with "required extension
... is not installed". That is annoying, especially when that dependency
is an implementation detail of the extension, rather than something the
extension's user can make sense of.

In addition to CASCADE this also includes a small set of regression
tests around CREATE EXTENSION.

Author: Petr Jelinek, editorialized by Michael Paquier, Andres Freund
Reviewed-By: Michael Paquier, Andres Freund, Jeff Janes,
Discussion: 557E0520.3040800@2ndquadrant.com
---
 contrib/hstore_plperl/expected/hstore_plperl.out   |   6 +-
 contrib/hstore_plperl/expected/hstore_plperlu.out  |   6 +-
 contrib/hstore_plperl/sql/hstore_plperl.sql        |   4 +-
 contrib/hstore_plperl/sql/hstore_plperlu.sql       |   4 +-
 .../hstore_plpython/expected/hstore_plpython.out   |   4 +-
 contrib/hstore_plpython/sql/hstore_plpython.sql    |   3 +-
 contrib/ltree_plpython/expected/ltree_plpython.out |   4 +-
 contrib/ltree_plpython/sql/ltree_plpython.sql      |   3 +-
 doc/src/sgml/ref/create_extension.sgml             |  42 ++++
 src/backend/commands/extension.c                   | 217 ++++++++++++++-------
 src/backend/parser/gram.y                          |   4 +
 src/bin/psql/tab-complete.c                        |   7 +-
 src/test/modules/Makefile                          |   1 +
 src/test/modules/test_extensions/.gitignore        |   4 +
 src/test/modules/test_extensions/Makefile          |  21 ++
 .../test_extensions/expected/test_extensions.out   |  30 +++
 .../test_extensions/sql/test_extensions.sql        |  18 ++
 .../modules/test_extensions/test_ext1--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext1.control |   5 +
 .../modules/test_extensions/test_ext2--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext2.control |   4 +
 .../modules/test_extensions/test_ext3--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext3.control |   3 +
 .../test_extensions/test_ext_cyclic1--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic1.control       |   4 +
 .../test_extensions/test_ext_cyclic2--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic2.control       |   4 +
 src/tools/msvc/Mkvcbuild.pm                        |   3 +-
 28 files changed, 327 insertions(+), 89 deletions(-)
 create mode 100644 src/test/modules/test_extensions/.gitignore
 create mode 100644 src/test/modules/test_extensions/Makefile
 create mode 100644 src/test/modules/test_extensions/expected/test_extensions.out
 create mode 100644 src/test/modules/test_extensions/sql/test_extensions.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1.control
 create mode 100644 src/test/modules/test_extensions/test_ext2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext2.control
 create mode 100644 src/test/modules/test_extensions/test_ext3--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext3.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2.control

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index cf384eb..25fc506 100644
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperl"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/expected/hstore_plperlu.out b/contrib/hstore_plperl/expected/hstore_plperlu.out
index c97fd3f..b09fb78 100644
--- a/contrib/hstore_plperl/expected/hstore_plperlu.out
+++ b/contrib/hstore_plperl/expected/hstore_plperlu.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperlu"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 0f70f14..9398aed 100644
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plperl/sql/hstore_plperlu.sql b/contrib/hstore_plperl/sql/hstore_plperlu.sql
index 3cfb2fd..8d8508c 100644
--- a/contrib/hstore_plperl/sql/hstore_plperlu.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperlu.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index 23091d3..b0025c0 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 -- test hstore -> python
 CREATE FUNCTION test1(val hstore) RETURNS int
 LANGUAGE plpythonu
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index 9ff2ebc..d55beda 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
 
 
 -- test hstore -> python
diff --git a/contrib/ltree_plpython/expected/ltree_plpython.out b/contrib/ltree_plpython/expected/ltree_plpython.out
index c6e8a7c..4779755 100644
--- a/contrib/ltree_plpython/expected/ltree_plpython.out
+++ b/contrib/ltree_plpython/expected/ltree_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 CREATE FUNCTION test1(val ltree) RETURNS int
 LANGUAGE plpythonu
 TRANSFORM FOR TYPE ltree
diff --git a/contrib/ltree_plpython/sql/ltree_plpython.sql b/contrib/ltree_plpython/sql/ltree_plpython.sql
index f08ff6a..210f542 100644
--- a/contrib/ltree_plpython/sql/ltree_plpython.sql
+++ b/contrib/ltree_plpython/sql/ltree_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
 
 
 CREATE FUNCTION test1(val ltree) RETURNS int
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index a1e7e4f8..d4cc310 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -25,6 +25,7 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
     [ WITH ] [ SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
              [ VERSION <replaceable class="parameter">version</replaceable> ]
              [ FROM <replaceable class="parameter">old_version</replaceable> ]
+             [ CASCADE ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -95,6 +96,35 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         schema either, the current default object creation schema is used.
        </para>
        <para>
+        If the extension specifies <literal>schema</> in its control file,
+        the schema cannot be overriden with <literal>SCHEMA</> clause.
+        The <literal>SCHEMA</> clause in this case works as follows:
+        <itemizedlist>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> matches
+           the schema in control file, it will be used normally as there is no
+           conflict.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If the <literal>CASCADE</> clause is given, the
+           <replaceable class="parameter">schema_name</replaceable> will only
+           be used for the missing required extensions which do not specify
+           <literal>schema</> in their control files.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> is not
+           the same as the one in extension's control file and the
+           <literal>CASCADE</> clause is not given, error will be thrown.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+       <para>
         Remember that the extension itself is not considered to be within any
         schema: extensions have unqualified names that must be unique
         database-wide.  But objects belonging to the extension can be within
@@ -139,6 +169,18 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry>
+      <term><literal>CASCADE</></term>
+      <listitem>
+       <para>
+        Try to install extension including the required dependencies
+        recursively. The <literal>SCHEMA</> option will be propagated
+        to the required extensions.  Other options are not recursively
+        applied when using this clause.
+       </para>
+      </listitem>
+     </varlistentry>
   </variablelist>
  </refsect1>
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 6b92bdc..67b16a7 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -43,11 +43,13 @@
 #include "catalog/pg_type.h"
 #include "commands/alter.h"
 #include "commands/comment.h"
+#include "commands/defrem.h"
 #include "commands/extension.h"
 #include "commands/schemacmds.h"
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "storage/fd.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -1165,18 +1167,25 @@ find_update_path(List *evi_list,
 }
 
 /*
- * CREATE EXTENSION
+ * CREATE EXTENSION worker
+ *
+ * When CASCADE is specified CreateExtensionInternal() recurses if required
+ * extensions need to be installed. To sanely handle cyclic dependencies
+ * cascade_parent contains the dependency chain leading to the current
+ * invocation; thus allowing to error out if there's a cyclic dependency.
  */
-ObjectAddress
-CreateExtension(CreateExtensionStmt *stmt)
+static ObjectAddress
+CreateExtensionInternal(CreateExtensionStmt *stmt, List *parents)
 {
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
 	DefElem    *d_old_version = NULL;
-	char	   *schemaName;
-	Oid			schemaOid;
+	DefElem    *d_cascade = NULL;
+	char	   *schemaName = NULL;
+	Oid			schemaOid = InvalidOid;
 	char	   *versionName;
 	char	   *oldVersionName;
+	bool		cascade = false;
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
@@ -1187,41 +1196,6 @@ CreateExtension(CreateExtensionStmt *stmt)
 	ListCell   *lc;
 	ObjectAddress address;
 
-	/* Check extension name validity before any filesystem access */
-	check_valid_extension_name(stmt->extname);
-
-	/*
-	 * Check for duplicate extension name.  The unique index on
-	 * pg_extension.extname would catch this anyway, and serves as a backstop
-	 * in case of race conditions; but this is a friendlier error message, and
-	 * besides we need a check to support IF NOT EXISTS.
-	 */
-	if (get_extension_oid(stmt->extname, true) != InvalidOid)
-	{
-		if (stmt->if_not_exists)
-		{
-			ereport(NOTICE,
-					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("extension \"%s\" already exists, skipping",
-							stmt->extname)));
-			return InvalidObjectAddress;
-		}
-		else
-			ereport(ERROR,
-					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("extension \"%s\" already exists",
-							stmt->extname)));
-	}
-
-	/*
-	 * We use global variables to track the extension being created, so we can
-	 * create only one extension at the same time.
-	 */
-	if (creating_extension)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("nested CREATE EXTENSION is not supported")));
-
 	/*
 	 * Read the primary control file.  Note we assume that it does not contain
 	 * any non-ASCII data, so there is no need to worry about encoding at this
@@ -1260,6 +1234,15 @@ CreateExtension(CreateExtensionStmt *stmt)
 						 errmsg("conflicting or redundant options")));
 			d_old_version = defel;
 		}
+		else if (strcmp(defel->defname, "cascade") == 0)
+		{
+			if (d_cascade)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_cascade = defel;
+			cascade = defGetBoolean(d_cascade);
+		}
 		else
 			elog(ERROR, "unrecognized option: %s", defel->defname);
 	}
@@ -1337,33 +1320,37 @@ CreateExtension(CreateExtensionStmt *stmt)
 	{
 		/*
 		 * User given schema, CREATE EXTENSION ... WITH SCHEMA ...
-		 *
-		 * It's an error to give a schema different from control->schema if
-		 * control->schema is specified.
 		 */
 		schemaName = strVal(d_schema->arg);
 
-		if (control->schema != NULL &&
-			strcmp(control->schema, schemaName) != 0)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				errmsg("extension \"%s\" must be installed in schema \"%s\"",
-					   control->name,
-					   control->schema)));
-
-		/* If the user is giving us the schema name, it must exist already */
+		/* If the user is giving us the schema name, it must exist already. */
 		schemaOid = get_namespace_oid(schemaName, false);
 	}
-	else if (control->schema != NULL)
+
+	if (control->schema != NULL)
 	{
 		/*
 		 * The extension is not relocatable and the author gave us a schema
-		 * for it.  We create the schema here if it does not already exist.
+		 * for it.
+		 *
+		 * Unless CASCADE parameter was given, it's an error to give a schema
+		 * different from control->schema if control->schema is specified.
 		 */
+		if (schemaName && strcmp(control->schema, schemaName) != 0 &&
+			!cascade)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("extension \"%s\" must be installed in schema \"%s\"",
+					   control->name,
+					   control->schema)));
+
+		/* Always use the schema from control file for current extension. */
 		schemaName = control->schema;
+
+		/* Find or create the schema in case it does not exist. */
 		schemaOid = get_namespace_oid(schemaName, true);
 
-		if (schemaOid == InvalidOid)
+		if (!OidIsValid(schemaOid))
 		{
 			CreateSchemaStmt *csstmt = makeNode(CreateSchemaStmt);
 
@@ -1375,16 +1362,17 @@ CreateExtension(CreateExtensionStmt *stmt)
 
 			/*
 			 * CreateSchemaCommand includes CommandCounterIncrement, so new
-			 * schema is now visible
+			 * schema is now visible.
 			 */
 			schemaOid = get_namespace_oid(schemaName, false);
 		}
 	}
-	else
+	else if (!OidIsValid(schemaOid))
 	{
 		/*
-		 * Else, use the current default creation namespace, which is the
-		 * first explicit entry in the search_path.
+		 * Neither user nor author of the extension specified schema, use the
+		 * current default creation namespace, which is the first explicit
+		 * entry in the search_path.
 		 */
 		List	   *search_path = fetch_search_path(false);
 
@@ -1423,16 +1411,65 @@ CreateExtension(CreateExtensionStmt *stmt)
 		Oid			reqext;
 		Oid			reqschema;
 
-		/*
-		 * We intentionally don't use get_extension_oid's default error
-		 * message here, because it would be confusing in this context.
-		 */
 		reqext = get_extension_oid(curreq, true);
 		if (!OidIsValid(reqext))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("required extension \"%s\" is not installed",
-							curreq)));
+		{
+			if (cascade)
+			{
+				CreateExtensionStmt *ces;
+				ListCell   *lc;
+				ObjectAddress addr;
+				List *cascade_parents;
+
+				/* Check extension name validity before trying to cascade */
+				check_valid_extension_name(curreq);
+
+				/* Check for cyclic dependency between extensions. */
+				foreach(lc, parents)
+				{
+					char	   *pname = (char *) lfirst(lc);
+
+					if (strcmp(pname, curreq) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_RECURSION),
+								 errmsg("cyclic dependency detected between extensions \"%s\" and \"%s\"",
+										curreq, stmt->extname)));
+				}
+
+				ereport(NOTICE,
+						(errmsg("installing required extension \"%s\"",
+								curreq)));
+
+				/* Create and execute new CREATE EXTENSION statement. */
+				ces = makeNode(CreateExtensionStmt);
+				ces->extname = curreq;
+
+				/* Propagate the CASCADE option */
+				ces->options = list_make1(d_cascade);
+
+				/* Propagate the SCHEMA option if given. */
+				if (d_schema && d_schema->arg)
+					ces->options = lappend(ces->options, d_schema);
+
+				/*
+				 * Pass the current list of parents + the current extension to
+				 * the "child" CreateExtensionInternal().
+				 */
+				cascade_parents =
+					lappend(list_copy(parents), stmt->extname);
+
+				/* Create the required extension. */
+				addr = CreateExtensionInternal(ces, cascade_parents);
+				reqext = addr.objectId;
+			}
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("required extension \"%s\" is not installed",
+								curreq),
+						 errhint("Use CREATE EXTENSION CASCADE to install required extensions too.")));
+		}
+
 		reqschema = get_extension_schema(reqext);
 		requiredExtensions = lappend_oid(requiredExtensions, reqext);
 		requiredSchemas = lappend_oid(requiredSchemas, reqschema);
@@ -1474,6 +1511,52 @@ CreateExtension(CreateExtensionStmt *stmt)
 }
 
 /*
+ * CREATE EXTENSION
+ */
+ObjectAddress
+CreateExtension(CreateExtensionStmt *stmt)
+{
+	/* Check extension name validity before any filesystem access */
+	check_valid_extension_name(stmt->extname);
+
+	/*
+	 * Check for duplicate extension name.  The unique index on
+	 * pg_extension.extname would catch this anyway, and serves as a backstop
+	 * in case of race conditions; but this is a friendlier error message, and
+	 * besides we need a check to support IF NOT EXISTS.
+	 */
+	if (get_extension_oid(stmt->extname, true) != InvalidOid)
+	{
+		if (stmt->if_not_exists)
+		{
+			ereport(NOTICE,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("extension \"%s\" already exists, skipping",
+							stmt->extname)));
+			return InvalidObjectAddress;
+		}
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("extension \"%s\" already exists",
+							stmt->extname)));
+	}
+
+	/*
+	 * We use global variables to track the extension being created, so we can
+	 * create only one extension at the same time.
+	 */
+	if (creating_extension)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("nested CREATE EXTENSION is not supported")));
+
+
+	/* Finally create the extension. */
+	return CreateExtensionInternal(stmt, NIL);
+}
+
+/*
  * InsertExtensionTuple
  *
  * Insert the new pg_extension row, and create extension's dependency entries.
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index fb84937..417fb55b 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3876,6 +3876,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("old_version", (Node *)makeString($2));
 				}
+			| CASCADE
+				{
+					$$ = makeDefElem("cascade", (Node *)makeInteger(TRUE));
+				}
 		;
 
 /*****************************************************************************
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 4294ffd..1619de5 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2264,7 +2264,12 @@ psql_completion(const char *text, int start, int end)
 	/* CREATE EXTENSION <name> */
 	else if (pg_strcasecmp(prev3_wd, "CREATE") == 0 &&
 			 pg_strcasecmp(prev2_wd, "EXTENSION") == 0)
-		COMPLETE_WITH_CONST("WITH SCHEMA");
+	{
+		static const char *const list_CREATE_EXTENSION[] =
+		{"WITH SCHEMA", "CASCADE", NULL};
+
+		COMPLETE_WITH_LIST(list_CREATE_EXTENSION);
+	}
 
 	/* CREATE FOREIGN */
 	else if (pg_strcasecmp(prev2_wd, "CREATE") == 0 &&
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 9b96654..6167ec1 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -9,6 +9,7 @@ SUBDIRS = \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \
+		  test_extensions \
 		  test_parser \
 		  test_rls_hooks \
 		  test_shm_mq \
diff --git a/src/test/modules/test_extensions/.gitignore b/src/test/modules/test_extensions/.gitignore
new file mode 100644
index 0000000..5dcb3ff
--- /dev/null
+++ b/src/test/modules/test_extensions/.gitignore
@@ -0,0 +1,4 @@
+# Generated subdirectories
+/log/
+/results/
+/tmp_check/
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
new file mode 100644
index 0000000..6c50e6c
--- /dev/null
+++ b/src/test/modules/test_extensions/Makefile
@@ -0,0 +1,21 @@
+# src/test/modules/test_extensions/Makefile
+
+MODULE = test_extensions
+PGFILEDESC = "test_extensions - regression testing for EXTENSION support"
+
+EXTENSION = test_ext1 test_ext2 test_ext3 test_ext_cyclic1 test_ext_cyclic2
+DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
+	   test_ext_cyclic1--1.0.sql test_ext_cyclic2--1.0.sql
+
+REGRESS = test_extensions
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_extensions
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
new file mode 100644
index 0000000..d95e7e0
--- /dev/null
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -0,0 +1,30 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+ERROR:  required extension "test_ext2" is not installed
+HINT:  Use CREATE EXTENSION CASCADE to install required extensions too.
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+ERROR:  schema "test_ext1" does not exist
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  schema "test_ext" does not exist
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+NOTICE:  installing required extension "test_ext2"
+NOTICE:  installing required extension "test_ext3"
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid ORDER BY 1;
+  extname  |  nspname  | extversion | extrelocatable 
+-----------+-----------+------------+----------------
+ test_ext1 | test_ext1 | 1.0        | f
+ test_ext2 | test_ext  | 1.0        | t
+ test_ext3 | test_ext  | 1.0        | t
+(3 rows)
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+NOTICE:  installing required extension "test_ext_cyclic2"
+ERROR:  cyclic dependency detected between extensions "test_ext_cyclic1" and "test_ext_cyclic2"
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
new file mode 100644
index 0000000..04c110a
--- /dev/null
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -0,0 +1,18 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid ORDER BY 1;
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+
+DROP EXTENSION test_ext1;
+DROP EXTENSION test_ext2;
+DROP EXTENSION test_ext3;
+DROP SCHEMA test_ext;
diff --git a/src/test/modules/test_extensions/test_ext1--1.0.sql b/src/test/modules/test_extensions/test_ext1--1.0.sql
new file mode 100644
index 0000000..9a4bb1b
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext1.control b/src/test/modules/test_extensions/test_ext1.control
new file mode 100644
index 0000000..ae50cd8
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1.control
@@ -0,0 +1,5 @@
+comment = 'Test extension 1'
+default_version = '1.0'
+schema = 'test_ext1'
+relocatable = false
+requires = 'test_ext2'
diff --git a/src/test/modules/test_extensions/test_ext2--1.0.sql b/src/test/modules/test_extensions/test_ext2--1.0.sql
new file mode 100644
index 0000000..0f6d4ec
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext2.control b/src/test/modules/test_extensions/test_ext2.control
new file mode 100644
index 0000000..788337e
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext3'
diff --git a/src/test/modules/test_extensions/test_ext3--1.0.sql b/src/test/modules/test_extensions/test_ext3--1.0.sql
new file mode 100644
index 0000000..7dec684
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext3--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext3" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext3.control b/src/test/modules/test_extensions/test_ext3.control
new file mode 100644
index 0000000..5f1afe7
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 3'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
new file mode 100644
index 0000000..81bdaf4
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1.control b/src/test/modules/test_extensions/test_ext_cyclic1.control
new file mode 100644
index 0000000..aaab403
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 1'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic2'
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
new file mode 100644
index 0000000..ae2b3e9
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2.control b/src/test/modules/test_extensions/test_ext_cyclic2.control
new file mode 100644
index 0000000..1e28f96
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic1'
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 3abbb4c..c122f02 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -41,7 +41,8 @@ my $contrib_extrasource = {
 	'seg'  => [ 'contrib/seg/segscan.l',   'contrib/seg/segparse.y' ], };
 my @contrib_excludes = (
 	'commit_ts',      'hstore_plperl', 'hstore_plpython', 'intagg',
-	'ltree_plpython', 'pgcrypto',      'sepgsql',         'brin');
+	'ltree_plpython', 'pgcrypto',      'sepgsql',         'brin',
+	'test_extensions');
 
 # Set of variables for frontend modules
 my $frontend_defines = { 'initdb' => 'FRONTEND' };
-- 
2.6.0.rc3

>From 54ce5b981e6d0009572562a989a287371a8c7146 Mon Sep 17 00:00:00 2001
From: Petr Jelinek <pjmodos@pjmodos.net>
Date: Sat, 3 Oct 2015 17:48:13 +0200
Subject: [PATCH] Add CASCADE support for CREATE EXTENSION.

Without CASCADE, if an extension has an unfullfilled dependency on
another extension, CREATE EXTENSION ERRORs out with "required extension
... is not installed". That is annoying, especially when that dependency
is an implementation detail of the extension, rather than something the
extension's user can make sense of.

In addition to CASCADE this also includes a small set of regression
tests around CREATE EXTENSION.

Author: Petr Jelinek, editorialized by Michael Paquier, Andres Freund
Reviewed-By: Michael Paquier, Andres Freund, Jeff Janes
Discussion: 557E0520.3040800@2ndquadrant.com
---
 contrib/hstore_plperl/expected/hstore_plperl.out   |   6 +-
 contrib/hstore_plperl/expected/hstore_plperlu.out  |   6 +-
 contrib/hstore_plperl/sql/hstore_plperl.sql        |   4 +-
 contrib/hstore_plperl/sql/hstore_plperlu.sql       |   4 +-
 .../hstore_plpython/expected/hstore_plpython.out   |   4 +-
 contrib/hstore_plpython/sql/hstore_plpython.sql    |   3 +-
 contrib/ltree_plpython/expected/ltree_plpython.out |   4 +-
 contrib/ltree_plpython/sql/ltree_plpython.sql      |   3 +-
 doc/src/sgml/ref/create_extension.sgml             |  42 ++++
 src/backend/commands/extension.c                   | 217 ++++++++++++++-------
 src/backend/parser/gram.y                          |   4 +
 src/bin/psql/tab-complete.c                        |   7 +-
 src/test/modules/Makefile                          |   1 +
 src/test/modules/test_extensions/.gitignore        |   4 +
 src/test/modules/test_extensions/Makefile          |  23 +++
 .../test_extensions/expected/test_extensions.out   |  37 ++++
 .../test_extensions/sql/test_extensions.sql        |  15 ++
 .../modules/test_extensions/test_ext1--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext1.control |   5 +
 .../modules/test_extensions/test_ext2--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext2.control |   4 +
 .../modules/test_extensions/test_ext3--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext3.control |   3 +
 .../modules/test_extensions/test_ext4--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext4.control |   4 +
 .../modules/test_extensions/test_ext5--1.0.sql     |   3 +
 src/test/modules/test_extensions/test_ext5.control |   3 +
 .../test_extensions/test_ext_cyclic1--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic1.control       |   4 +
 .../test_extensions/test_ext_cyclic2--1.0.sql      |   3 +
 .../test_extensions/test_ext_cyclic2.control       |   4 +
 src/tools/msvc/Mkvcbuild.pm                        |   3 +-
 32 files changed, 346 insertions(+), 89 deletions(-)
 create mode 100644 src/test/modules/test_extensions/.gitignore
 create mode 100644 src/test/modules/test_extensions/Makefile
 create mode 100644 src/test/modules/test_extensions/expected/test_extensions.out
 create mode 100644 src/test/modules/test_extensions/sql/test_extensions.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext1.control
 create mode 100644 src/test/modules/test_extensions/test_ext2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext2.control
 create mode 100644 src/test/modules/test_extensions/test_ext3--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext3.control
 create mode 100644 src/test/modules/test_extensions/test_ext4--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext4.control
 create mode 100644 src/test/modules/test_extensions/test_ext5--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext5.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic1.control
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
 create mode 100644 src/test/modules/test_extensions/test_ext_cyclic2.control

diff --git a/contrib/hstore_plperl/expected/hstore_plperl.out b/contrib/hstore_plperl/expected/hstore_plperl.out
index cf384eb..25fc506 100644
--- a/contrib/hstore_plperl/expected/hstore_plperl.out
+++ b/contrib/hstore_plperl/expected/hstore_plperl.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperl"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/expected/hstore_plperlu.out b/contrib/hstore_plperl/expected/hstore_plperlu.out
index c97fd3f..b09fb78 100644
--- a/contrib/hstore_plperl/expected/hstore_plperlu.out
+++ b/contrib/hstore_plperl/expected/hstore_plperlu.out
@@ -1,6 +1,6 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
+NOTICE:  installing required extension "hstore"
+NOTICE:  installing required extension "plperlu"
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
        group_name, transform_type
diff --git a/contrib/hstore_plperl/sql/hstore_plperl.sql b/contrib/hstore_plperl/sql/hstore_plperl.sql
index 0f70f14..9398aed 100644
--- a/contrib/hstore_plperl/sql/hstore_plperl.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperl.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperl;
-CREATE EXTENSION hstore_plperl;
+CREATE EXTENSION hstore_plperl CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plperl/sql/hstore_plperlu.sql b/contrib/hstore_plperl/sql/hstore_plperlu.sql
index 3cfb2fd..8d8508c 100644
--- a/contrib/hstore_plperl/sql/hstore_plperlu.sql
+++ b/contrib/hstore_plperl/sql/hstore_plperlu.sql
@@ -1,6 +1,4 @@
-CREATE EXTENSION hstore;
-CREATE EXTENSION plperlu;
-CREATE EXTENSION hstore_plperlu;
+CREATE EXTENSION hstore_plperlu CASCADE;
 
 SELECT transforms.udt_schema, transforms.udt_name,
        routine_schema, routine_name,
diff --git a/contrib/hstore_plpython/expected/hstore_plpython.out b/contrib/hstore_plpython/expected/hstore_plpython.out
index 23091d3..b0025c0 100644
--- a/contrib/hstore_plpython/expected/hstore_plpython.out
+++ b/contrib/hstore_plpython/expected/hstore_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 -- test hstore -> python
 CREATE FUNCTION test1(val hstore) RETURNS int
 LANGUAGE plpythonu
diff --git a/contrib/hstore_plpython/sql/hstore_plpython.sql b/contrib/hstore_plpython/sql/hstore_plpython.sql
index 9ff2ebc..d55beda 100644
--- a/contrib/hstore_plpython/sql/hstore_plpython.sql
+++ b/contrib/hstore_plpython/sql/hstore_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION hstore_plpython2u;
+CREATE EXTENSION hstore_plpython2u CASCADE;
 
 
 -- test hstore -> python
diff --git a/contrib/ltree_plpython/expected/ltree_plpython.out b/contrib/ltree_plpython/expected/ltree_plpython.out
index c6e8a7c..4779755 100644
--- a/contrib/ltree_plpython/expected/ltree_plpython.out
+++ b/contrib/ltree_plpython/expected/ltree_plpython.out
@@ -1,5 +1,5 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
+NOTICE:  installing required extension "plpython2u"
 CREATE FUNCTION test1(val ltree) RETURNS int
 LANGUAGE plpythonu
 TRANSFORM FOR TYPE ltree
diff --git a/contrib/ltree_plpython/sql/ltree_plpython.sql b/contrib/ltree_plpython/sql/ltree_plpython.sql
index f08ff6a..210f542 100644
--- a/contrib/ltree_plpython/sql/ltree_plpython.sql
+++ b/contrib/ltree_plpython/sql/ltree_plpython.sql
@@ -1,5 +1,4 @@
-CREATE EXTENSION plpython2u;
-CREATE EXTENSION ltree_plpython2u;
+CREATE EXTENSION ltree_plpython2u CASCADE;
 
 
 CREATE FUNCTION test1(val ltree) RETURNS int
diff --git a/doc/src/sgml/ref/create_extension.sgml b/doc/src/sgml/ref/create_extension.sgml
index a1e7e4f8..d4cc310 100644
--- a/doc/src/sgml/ref/create_extension.sgml
+++ b/doc/src/sgml/ref/create_extension.sgml
@@ -25,6 +25,7 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
     [ WITH ] [ SCHEMA <replaceable class="parameter">schema_name</replaceable> ]
              [ VERSION <replaceable class="parameter">version</replaceable> ]
              [ FROM <replaceable class="parameter">old_version</replaceable> ]
+             [ CASCADE ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -95,6 +96,35 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
         schema either, the current default object creation schema is used.
        </para>
        <para>
+        If the extension specifies <literal>schema</> in its control file,
+        the schema cannot be overriden with <literal>SCHEMA</> clause.
+        The <literal>SCHEMA</> clause in this case works as follows:
+        <itemizedlist>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> matches
+           the schema in control file, it will be used normally as there is no
+           conflict.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If the <literal>CASCADE</> clause is given, the
+           <replaceable class="parameter">schema_name</replaceable> will only
+           be used for the missing required extensions which do not specify
+           <literal>schema</> in their control files.
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If <replaceable class="parameter">schema_name</replaceable> is not
+           the same as the one in extension's control file and the
+           <literal>CASCADE</> clause is not given, error will be thrown.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+       <para>
         Remember that the extension itself is not considered to be within any
         schema: extensions have unqualified names that must be unique
         database-wide.  But objects belonging to the extension can be within
@@ -139,6 +169,18 @@ CREATE EXTENSION [ IF NOT EXISTS ] <replaceable class="parameter">extension_name
        </para>
       </listitem>
      </varlistentry>
+
+     <varlistentry>
+      <term><literal>CASCADE</></term>
+      <listitem>
+       <para>
+        Try to install extension including the required dependencies
+        recursively. The <literal>SCHEMA</> option will be propagated
+        to the required extensions.  Other options are not recursively
+        applied when using this clause.
+       </para>
+      </listitem>
+     </varlistentry>
   </variablelist>
  </refsect1>
 
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 6b92bdc..67b16a7 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -43,11 +43,13 @@
 #include "catalog/pg_type.h"
 #include "commands/alter.h"
 #include "commands/comment.h"
+#include "commands/defrem.h"
 #include "commands/extension.h"
 #include "commands/schemacmds.h"
 #include "funcapi.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/makefuncs.h"
 #include "storage/fd.h"
 #include "tcop/utility.h"
 #include "utils/builtins.h"
@@ -1165,18 +1167,25 @@ find_update_path(List *evi_list,
 }
 
 /*
- * CREATE EXTENSION
+ * CREATE EXTENSION worker
+ *
+ * When CASCADE is specified CreateExtensionInternal() recurses if required
+ * extensions need to be installed. To sanely handle cyclic dependencies
+ * cascade_parent contains the dependency chain leading to the current
+ * invocation; thus allowing to error out if there's a cyclic dependency.
  */
-ObjectAddress
-CreateExtension(CreateExtensionStmt *stmt)
+static ObjectAddress
+CreateExtensionInternal(CreateExtensionStmt *stmt, List *parents)
 {
 	DefElem    *d_schema = NULL;
 	DefElem    *d_new_version = NULL;
 	DefElem    *d_old_version = NULL;
-	char	   *schemaName;
-	Oid			schemaOid;
+	DefElem    *d_cascade = NULL;
+	char	   *schemaName = NULL;
+	Oid			schemaOid = InvalidOid;
 	char	   *versionName;
 	char	   *oldVersionName;
+	bool		cascade = false;
 	Oid			extowner = GetUserId();
 	ExtensionControlFile *pcontrol;
 	ExtensionControlFile *control;
@@ -1187,41 +1196,6 @@ CreateExtension(CreateExtensionStmt *stmt)
 	ListCell   *lc;
 	ObjectAddress address;
 
-	/* Check extension name validity before any filesystem access */
-	check_valid_extension_name(stmt->extname);
-
-	/*
-	 * Check for duplicate extension name.  The unique index on
-	 * pg_extension.extname would catch this anyway, and serves as a backstop
-	 * in case of race conditions; but this is a friendlier error message, and
-	 * besides we need a check to support IF NOT EXISTS.
-	 */
-	if (get_extension_oid(stmt->extname, true) != InvalidOid)
-	{
-		if (stmt->if_not_exists)
-		{
-			ereport(NOTICE,
-					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("extension \"%s\" already exists, skipping",
-							stmt->extname)));
-			return InvalidObjectAddress;
-		}
-		else
-			ereport(ERROR,
-					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("extension \"%s\" already exists",
-							stmt->extname)));
-	}
-
-	/*
-	 * We use global variables to track the extension being created, so we can
-	 * create only one extension at the same time.
-	 */
-	if (creating_extension)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("nested CREATE EXTENSION is not supported")));
-
 	/*
 	 * Read the primary control file.  Note we assume that it does not contain
 	 * any non-ASCII data, so there is no need to worry about encoding at this
@@ -1260,6 +1234,15 @@ CreateExtension(CreateExtensionStmt *stmt)
 						 errmsg("conflicting or redundant options")));
 			d_old_version = defel;
 		}
+		else if (strcmp(defel->defname, "cascade") == 0)
+		{
+			if (d_cascade)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+			d_cascade = defel;
+			cascade = defGetBoolean(d_cascade);
+		}
 		else
 			elog(ERROR, "unrecognized option: %s", defel->defname);
 	}
@@ -1337,33 +1320,37 @@ CreateExtension(CreateExtensionStmt *stmt)
 	{
 		/*
 		 * User given schema, CREATE EXTENSION ... WITH SCHEMA ...
-		 *
-		 * It's an error to give a schema different from control->schema if
-		 * control->schema is specified.
 		 */
 		schemaName = strVal(d_schema->arg);
 
-		if (control->schema != NULL &&
-			strcmp(control->schema, schemaName) != 0)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				errmsg("extension \"%s\" must be installed in schema \"%s\"",
-					   control->name,
-					   control->schema)));
-
-		/* If the user is giving us the schema name, it must exist already */
+		/* If the user is giving us the schema name, it must exist already. */
 		schemaOid = get_namespace_oid(schemaName, false);
 	}
-	else if (control->schema != NULL)
+
+	if (control->schema != NULL)
 	{
 		/*
 		 * The extension is not relocatable and the author gave us a schema
-		 * for it.  We create the schema here if it does not already exist.
+		 * for it.
+		 *
+		 * Unless CASCADE parameter was given, it's an error to give a schema
+		 * different from control->schema if control->schema is specified.
 		 */
+		if (schemaName && strcmp(control->schema, schemaName) != 0 &&
+			!cascade)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("extension \"%s\" must be installed in schema \"%s\"",
+					   control->name,
+					   control->schema)));
+
+		/* Always use the schema from control file for current extension. */
 		schemaName = control->schema;
+
+		/* Find or create the schema in case it does not exist. */
 		schemaOid = get_namespace_oid(schemaName, true);
 
-		if (schemaOid == InvalidOid)
+		if (!OidIsValid(schemaOid))
 		{
 			CreateSchemaStmt *csstmt = makeNode(CreateSchemaStmt);
 
@@ -1375,16 +1362,17 @@ CreateExtension(CreateExtensionStmt *stmt)
 
 			/*
 			 * CreateSchemaCommand includes CommandCounterIncrement, so new
-			 * schema is now visible
+			 * schema is now visible.
 			 */
 			schemaOid = get_namespace_oid(schemaName, false);
 		}
 	}
-	else
+	else if (!OidIsValid(schemaOid))
 	{
 		/*
-		 * Else, use the current default creation namespace, which is the
-		 * first explicit entry in the search_path.
+		 * Neither user nor author of the extension specified schema, use the
+		 * current default creation namespace, which is the first explicit
+		 * entry in the search_path.
 		 */
 		List	   *search_path = fetch_search_path(false);
 
@@ -1423,16 +1411,65 @@ CreateExtension(CreateExtensionStmt *stmt)
 		Oid			reqext;
 		Oid			reqschema;
 
-		/*
-		 * We intentionally don't use get_extension_oid's default error
-		 * message here, because it would be confusing in this context.
-		 */
 		reqext = get_extension_oid(curreq, true);
 		if (!OidIsValid(reqext))
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("required extension \"%s\" is not installed",
-							curreq)));
+		{
+			if (cascade)
+			{
+				CreateExtensionStmt *ces;
+				ListCell   *lc;
+				ObjectAddress addr;
+				List *cascade_parents;
+
+				/* Check extension name validity before trying to cascade */
+				check_valid_extension_name(curreq);
+
+				/* Check for cyclic dependency between extensions. */
+				foreach(lc, parents)
+				{
+					char	   *pname = (char *) lfirst(lc);
+
+					if (strcmp(pname, curreq) == 0)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_RECURSION),
+								 errmsg("cyclic dependency detected between extensions \"%s\" and \"%s\"",
+										curreq, stmt->extname)));
+				}
+
+				ereport(NOTICE,
+						(errmsg("installing required extension \"%s\"",
+								curreq)));
+
+				/* Create and execute new CREATE EXTENSION statement. */
+				ces = makeNode(CreateExtensionStmt);
+				ces->extname = curreq;
+
+				/* Propagate the CASCADE option */
+				ces->options = list_make1(d_cascade);
+
+				/* Propagate the SCHEMA option if given. */
+				if (d_schema && d_schema->arg)
+					ces->options = lappend(ces->options, d_schema);
+
+				/*
+				 * Pass the current list of parents + the current extension to
+				 * the "child" CreateExtensionInternal().
+				 */
+				cascade_parents =
+					lappend(list_copy(parents), stmt->extname);
+
+				/* Create the required extension. */
+				addr = CreateExtensionInternal(ces, cascade_parents);
+				reqext = addr.objectId;
+			}
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("required extension \"%s\" is not installed",
+								curreq),
+						 errhint("Use CREATE EXTENSION CASCADE to install required extensions too.")));
+		}
+
 		reqschema = get_extension_schema(reqext);
 		requiredExtensions = lappend_oid(requiredExtensions, reqext);
 		requiredSchemas = lappend_oid(requiredSchemas, reqschema);
@@ -1474,6 +1511,52 @@ CreateExtension(CreateExtensionStmt *stmt)
 }
 
 /*
+ * CREATE EXTENSION
+ */
+ObjectAddress
+CreateExtension(CreateExtensionStmt *stmt)
+{
+	/* Check extension name validity before any filesystem access */
+	check_valid_extension_name(stmt->extname);
+
+	/*
+	 * Check for duplicate extension name.  The unique index on
+	 * pg_extension.extname would catch this anyway, and serves as a backstop
+	 * in case of race conditions; but this is a friendlier error message, and
+	 * besides we need a check to support IF NOT EXISTS.
+	 */
+	if (get_extension_oid(stmt->extname, true) != InvalidOid)
+	{
+		if (stmt->if_not_exists)
+		{
+			ereport(NOTICE,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("extension \"%s\" already exists, skipping",
+							stmt->extname)));
+			return InvalidObjectAddress;
+		}
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_DUPLICATE_OBJECT),
+					 errmsg("extension \"%s\" already exists",
+							stmt->extname)));
+	}
+
+	/*
+	 * We use global variables to track the extension being created, so we can
+	 * create only one extension at the same time.
+	 */
+	if (creating_extension)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("nested CREATE EXTENSION is not supported")));
+
+
+	/* Finally create the extension. */
+	return CreateExtensionInternal(stmt, NIL);
+}
+
+/*
  * InsertExtensionTuple
  *
  * Insert the new pg_extension row, and create extension's dependency entries.
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index fb84937..417fb55 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -3876,6 +3876,10 @@ create_extension_opt_item:
 				{
 					$$ = makeDefElem("old_version", (Node *)makeString($2));
 				}
+			| CASCADE
+				{
+					$$ = makeDefElem("cascade", (Node *)makeInteger(TRUE));
+				}
 		;
 
 /*****************************************************************************
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 4294ffd..1619de5 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2264,7 +2264,12 @@ psql_completion(const char *text, int start, int end)
 	/* CREATE EXTENSION <name> */
 	else if (pg_strcasecmp(prev3_wd, "CREATE") == 0 &&
 			 pg_strcasecmp(prev2_wd, "EXTENSION") == 0)
-		COMPLETE_WITH_CONST("WITH SCHEMA");
+	{
+		static const char *const list_CREATE_EXTENSION[] =
+		{"WITH SCHEMA", "CASCADE", NULL};
+
+		COMPLETE_WITH_LIST(list_CREATE_EXTENSION);
+	}
 
 	/* CREATE FOREIGN */
 	else if (pg_strcasecmp(prev2_wd, "CREATE") == 0 &&
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index 9b96654..6167ec1 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -9,6 +9,7 @@ SUBDIRS = \
 		  commit_ts \
 		  dummy_seclabel \
 		  test_ddl_deparse \
+		  test_extensions \
 		  test_parser \
 		  test_rls_hooks \
 		  test_shm_mq \
diff --git a/src/test/modules/test_extensions/.gitignore b/src/test/modules/test_extensions/.gitignore
new file mode 100644
index 0000000..5dcb3ff
--- /dev/null
+++ b/src/test/modules/test_extensions/.gitignore
@@ -0,0 +1,4 @@
+# Generated subdirectories
+/log/
+/results/
+/tmp_check/
diff --git a/src/test/modules/test_extensions/Makefile b/src/test/modules/test_extensions/Makefile
new file mode 100644
index 0000000..5691357
--- /dev/null
+++ b/src/test/modules/test_extensions/Makefile
@@ -0,0 +1,23 @@
+# src/test/modules/test_extensions/Makefile
+
+MODULE = test_extensions
+PGFILEDESC = "test_extensions - regression testing for EXTENSION support"
+
+EXTENSION = test_ext1 test_ext2 test_ext3 test_ext4 test_ext5 \
+			test_ext_cyclic1 test_ext_cyclic2
+DATA = test_ext1--1.0.sql test_ext2--1.0.sql test_ext3--1.0.sql \
+	   test_ext4--1.0.sql test_ext5--1.0.sql test_ext_cyclic1--1.0.sql \
+	   test_ext_cyclic2--1.0.sql
+
+REGRESS = test_extensions
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/test_extensions
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/test_extensions/expected/test_extensions.out b/src/test/modules/test_extensions/expected/test_extensions.out
new file mode 100644
index 0000000..a57bb4b
--- /dev/null
+++ b/src/test/modules/test_extensions/expected/test_extensions.out
@@ -0,0 +1,37 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+ERROR:  required extension "test_ext2" is not installed
+HINT:  Use CREATE EXTENSION CASCADE to install required extensions too.
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+ERROR:  schema "test_ext1" does not exist
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  schema "test_ext" does not exist
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+ERROR:  extension "test_ext1" must be installed in schema "test_ext1"
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+NOTICE:  installing required extension "test_ext2"
+NOTICE:  installing required extension "test_ext3"
+NOTICE:  installing required extension "test_ext5"
+NOTICE:  installing required extension "test_ext4"
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid ORDER BY 1;
+  extname  |  nspname  | extversion | extrelocatable 
+-----------+-----------+------------+----------------
+ test_ext1 | test_ext1 | 1.0        | f
+ test_ext2 | test_ext  | 1.0        | t
+ test_ext3 | test_ext  | 1.0        | t
+ test_ext4 | test_ext  | 1.0        | t
+ test_ext5 | test_ext  | 1.0        | t
+(5 rows)
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+NOTICE:  installing required extension "test_ext_cyclic2"
+ERROR:  cyclic dependency detected between extensions "test_ext_cyclic1" and "test_ext_cyclic2"
+DROP SCHEMA test_ext CASCADE;
+NOTICE:  drop cascades to 5 other objects
+DETAIL:  drop cascades to extension test_ext3
+drop cascades to extension test_ext5
+drop cascades to extension test_ext2
+drop cascades to extension test_ext4
+drop cascades to extension test_ext1
diff --git a/src/test/modules/test_extensions/sql/test_extensions.sql b/src/test/modules/test_extensions/sql/test_extensions.sql
new file mode 100644
index 0000000..9076c02
--- /dev/null
+++ b/src/test/modules/test_extensions/sql/test_extensions.sql
@@ -0,0 +1,15 @@
+-- test some errors
+CREATE EXTENSION test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext1;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+CREATE SCHEMA test_ext;
+CREATE EXTENSION test_ext1 SCHEMA test_ext;
+
+-- finally success
+CREATE EXTENSION test_ext1 SCHEMA test_ext CASCADE;
+
+SELECT extname, nspname, extversion, extrelocatable FROM pg_extension e, pg_namespace n WHERE extname LIKE 'test_ext%' AND e.extnamespace = n.oid ORDER BY 1;
+
+CREATE EXTENSION test_ext_cyclic1 CASCADE;
+
+DROP SCHEMA test_ext CASCADE;
diff --git a/src/test/modules/test_extensions/test_ext1--1.0.sql b/src/test/modules/test_extensions/test_ext1--1.0.sql
new file mode 100644
index 0000000..9a4bb1b
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext1.control b/src/test/modules/test_extensions/test_ext1.control
new file mode 100644
index 0000000..9c069df
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext1.control
@@ -0,0 +1,5 @@
+comment = 'Test extension 1'
+default_version = '1.0'
+schema = 'test_ext1'
+relocatable = false
+requires = 'test_ext2,test_ext4'
diff --git a/src/test/modules/test_extensions/test_ext2--1.0.sql b/src/test/modules/test_extensions/test_ext2--1.0.sql
new file mode 100644
index 0000000..0f6d4ec
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext2.control b/src/test/modules/test_extensions/test_ext2.control
new file mode 100644
index 0000000..946b7d5
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext3,test_ext5'
diff --git a/src/test/modules/test_extensions/test_ext3--1.0.sql b/src/test/modules/test_extensions/test_ext3--1.0.sql
new file mode 100644
index 0000000..7dec684
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext3--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext3" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext3.control b/src/test/modules/test_extensions/test_ext3.control
new file mode 100644
index 0000000..5f1afe7
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext3.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 3'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext4--1.0.sql b/src/test/modules/test_extensions/test_ext4--1.0.sql
new file mode 100644
index 0000000..19f051f
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext4--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext4--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext4" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext4.control b/src/test/modules/test_extensions/test_ext4.control
new file mode 100644
index 0000000..fc62591
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext4.control
@@ -0,0 +1,4 @@
+comment = 'Test extension 4'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext5'
diff --git a/src/test/modules/test_extensions/test_ext5--1.0.sql b/src/test/modules/test_extensions/test_ext5--1.0.sql
new file mode 100644
index 0000000..baf6ef8
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext5--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext5--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext5" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext5.control b/src/test/modules/test_extensions/test_ext5.control
new file mode 100644
index 0000000..51bc57e
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext5.control
@@ -0,0 +1,3 @@
+comment = 'Test extension 5'
+default_version = '1.0'
+relocatable = true
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
new file mode 100644
index 0000000..81bdaf4
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic1--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic1" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic1.control b/src/test/modules/test_extensions/test_ext_cyclic1.control
new file mode 100644
index 0000000..aaab403
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic1.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 1'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic2'
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
new file mode 100644
index 0000000..ae2b3e9
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql
@@ -0,0 +1,3 @@
+/* src/test/modules/test_extensions/test_ext_cyclic2--1.0.sql */
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION test_ext_cyclic2" to load this file. \quit
diff --git a/src/test/modules/test_extensions/test_ext_cyclic2.control b/src/test/modules/test_extensions/test_ext_cyclic2.control
new file mode 100644
index 0000000..1e28f96
--- /dev/null
+++ b/src/test/modules/test_extensions/test_ext_cyclic2.control
@@ -0,0 +1,4 @@
+comment = 'Test extension cyclic 2'
+default_version = '1.0'
+relocatable = true
+requires = 'test_ext_cyclic1'
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index 3abbb4c..c122f02 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -41,7 +41,8 @@ my $contrib_extrasource = {
 	'seg'  => [ 'contrib/seg/segscan.l',   'contrib/seg/segparse.y' ], };
 my @contrib_excludes = (
 	'commit_ts',      'hstore_plperl', 'hstore_plpython', 'intagg',
-	'ltree_plpython', 'pgcrypto',      'sepgsql',         'brin');
+	'ltree_plpython', 'pgcrypto',      'sepgsql',         'brin',
+	'test_extensions');
 
 # Set of variables for frontend modules
 my $frontend_defines = { 'initdb' => 'FRONTEND' };
-- 
1.9.1