From 471775d8b6a4bb90dd0570a4c834e9cddd5fefa3 Mon Sep 17 00:00:00 2001
From: Ayush Vatsa <ayuvatsa@amazon.com>
Date: Mon, 25 Dec 2023 14:46:05 +0530
Subject: [PATCH] Add support for --exclude-extension in pg_dump

When specified, extensions matching the given pattern are excluded
in dumps.
---
 doc/src/sgml/ref/pg_dump.sgml | 24 +++++++++++++++++++++++-
 src/bin/pg_dump/pg_dump.c     | 28 ++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index 0e5ba4f712..b3f3ff3188 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -256,6 +256,27 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--exclude-extension=<replaceable class="parameter">pattern</replaceable></option></term>
+      <listitem>
+       <para>
+        Do not dump any extensions matching <replaceable
+        class="parameter">pattern</replaceable>.  The pattern is
+        interpreted according to the same rules as for <option>-e</option>.
+        <option>--exclude-extension</option> can be given more than once to exclude extensions
+        matching any of several patterns.
+       </para>
+
+       <para>
+        When both <option>-e</option> and <option>--exclude-extension</option> are given, the behavior
+        is to dump just the extensions that match at least one <option>-e</option>
+        switch but no <option>--exclude-extension</option> switches.  If <option>--exclude-extension</option>
+        appears without <option>-e</option>, then extensions matching <option>--exclude-extension</option> are
+        excluded from what is otherwise a normal dump.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-E <replaceable class="parameter">encoding</replaceable></option></term>
       <term><option>--encoding=<replaceable class="parameter">encoding</replaceable></option></term>
@@ -1278,7 +1299,8 @@ PostgreSQL documentation
        </para>
        <para>
         This option has no effect
-        on <option>-N</option>/<option>--exclude-schema</option>,
+        on <option>--exclude-extension</option>,
+        <option>-N</option>/<option>--exclude-schema</option>,
         <option>-T</option>/<option>--exclude-table</option>,
         or <option>--exclude-table-data</option>.  An exclude pattern failing
         to match any objects is not considered an error.
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 8c0b5486b9..1185c74a54 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -136,6 +136,9 @@ static SimpleOidList foreign_servers_include_oids = {NULL, NULL};
 static SimpleStringList extension_include_patterns = {NULL, NULL};
 static SimpleOidList extension_include_oids = {NULL, NULL};
 
+static SimpleStringList extension_exclude_patterns = {NULL, NULL};
+static SimpleOidList extension_exclude_oids = {NULL, NULL};
+
 static const CatalogId nilCatalogId = {0, 0};
 
 /* override for standard extra_float_digits setting */
@@ -436,6 +439,7 @@ main(int argc, char **argv)
 		{"exclude-table-data-and-children", required_argument, NULL, 14},
 		{"sync-method", required_argument, NULL, 15},
 		{"filter", required_argument, NULL, 16},
+		{"exclude-extension", required_argument, NULL, 17},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -671,6 +675,11 @@ main(int argc, char **argv)
 				read_dump_filters(optarg, &dopt);
 				break;
 
+			case 17:			/* exclude extension(s) */
+				simple_string_list_append(&extension_exclude_patterns,
+										  optarg);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -889,6 +898,10 @@ main(int argc, char **argv)
 		if (extension_include_oids.head == NULL)
 			pg_fatal("no matching extensions were found");
 	}
+	expand_extension_name_patterns(fout, &extension_exclude_patterns,
+									&extension_exclude_oids,
+									false);
+	/* non-matching exclusion patterns aren't an error */
 
 	/*
 	 * Dumping LOs is the default for dumps where an inclusion switch is not
@@ -1094,6 +1107,7 @@ help(const char *progname)
 	printf(_("  -c, --clean                  clean (drop) database objects before recreating\n"));
 	printf(_("  -C, --create                 include commands to create database in dump\n"));
 	printf(_("  -e, --extension=PATTERN      dump the specified extension(s) only\n"));
+	printf(_("  --exclude-extension=PATTERN  do NOT dump the specified extension(s)\n"));
 	printf(_("  -E, --encoding=ENCODING      dump the data in encoding ENCODING\n"));
 	printf(_("  -n, --schema=PATTERN         dump the specified schema(s) only\n"));
 	printf(_("  -N, --exclude-schema=PATTERN do NOT dump the specified schema(s)\n"));
@@ -2025,6 +2039,11 @@ selectDumpableExtension(ExtensionInfo *extinfo, DumpOptions *dopt)
 			extinfo->dobj.dump = extinfo->dobj.dump_contains =
 				dopt->include_everything ?
 				DUMP_COMPONENT_ALL : DUMP_COMPONENT_NONE;
+
+		if (extension_exclude_oids.head != NULL && 
+				simple_oid_list_member(&extension_exclude_oids,
+									   extinfo->dobj.catId.oid))
+			extinfo->dobj.dump = extinfo->dobj.dump_contains = DUMP_COMPONENT_NONE;
 	}
 }
 
@@ -18149,6 +18168,15 @@ processExtensionTables(Archive *fout, ExtensionInfo extinfo[],
 			!simple_oid_list_member(&extension_include_oids,
 									curext->dobj.catId.oid))
 			continue;
+		
+		/*
+		 * Check if this extension is listed as to exclude in the dump.  If
+		 * yes, any table data associated with it is discarded.
+		 */
+		if (extension_exclude_oids.head != NULL &&
+			simple_oid_list_member(&extension_exclude_oids,
+									curext->dobj.catId.oid))
+			continue;
 
 		if (strlen(extconfig) != 0 || strlen(extcondition) != 0)
 		{
-- 
2.41.0