From 9f04d5a97652f6b08747ccc9af3b079fe1221d4b Mon Sep 17 00:00:00 2001
From: Matthias van de Meent <boekewurm@gmail.com>
Date: Mon, 8 Feb 2021 17:36:00 +0100
Subject: [PATCH v2 4/5] Add a command column to the copy progress view

This allows filtering on COPY FROM / COPY TO for progress reporting, and makes
it possible to determine the further meaning of the columns involved.
---
 doc/src/sgml/monitoring.sgml         | 10 ++++++++++
 src/backend/catalog/system_views.sql |  3 +++
 src/backend/commands/copyfrom.c      |  1 +
 src/backend/commands/copyto.c        |  1 +
 src/include/commands/progress.h      |  5 +++++
 src/test/regress/expected/rules.out  |  5 +++++
 6 files changed, 25 insertions(+)

diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 940e9dcee4..ca84b53896 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -6544,6 +6544,16 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid,
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>command</structfield> <type>text</type>
+      </para>
+      <para>
+       The command that is running: <literal>COPY FROM</literal>, or
+       <literal>COPY TO</literal>.
+      </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>bytes_processed</structfield> <type>bigint</type>
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index e7e227792c..1082b7d253 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1129,6 +1129,9 @@ CREATE VIEW pg_stat_progress_copy AS
     SELECT
         S.pid AS pid, S.datid AS datid, D.datname AS datname,
         S.relid AS relid,
+        CASE S.param5 WHEN 1 THEN 'COPY FROM'
+                      WHEN 2 THEN 'COPY TO'
+                      END AS command,
         S.param1 AS bytes_processed,
         S.param2 AS bytes_total,
         S.param3 AS tuples_processed,
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
index fb3c7e2c0c..ce343dbf80 100644
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -1428,6 +1428,7 @@ BeginCopyFrom(ParseState *pstate,
 	/* initialize progress */
 	pgstat_progress_start_command(PROGRESS_COMMAND_COPY,
 								  cstate->rel ? RelationGetRelid(cstate->rel) : InvalidOid);
+	pgstat_progress_update_param(PROGRESS_COPY_COMMAND, PROGRESS_COPY_COMMAND_FROM);
 	cstate->bytes_processed = 0;
 
 	/* We keep those variables in cstate. */
diff --git a/src/backend/commands/copyto.c b/src/backend/commands/copyto.c
index 9ffe7a6ee3..534c091c75 100644
--- a/src/backend/commands/copyto.c
+++ b/src/backend/commands/copyto.c
@@ -772,6 +772,7 @@ BeginCopyTo(ParseState *pstate,
 	/* initialize progress */
 	pgstat_progress_start_command(PROGRESS_COMMAND_COPY,
 								  cstate->rel ? RelationGetRelid(cstate->rel) : InvalidOid);
+	pgstat_progress_update_param(PROGRESS_COPY_COMMAND, PROGRESS_COPY_COMMAND_TO);
 	cstate->bytes_processed = 0;
 
 	MemoryContextSwitchTo(oldcontext);
diff --git a/src/include/commands/progress.h b/src/include/commands/progress.h
index 8b2b188bd5..1c30d09abb 100644
--- a/src/include/commands/progress.h
+++ b/src/include/commands/progress.h
@@ -138,5 +138,10 @@
 #define PROGRESS_COPY_BYTES_TOTAL 1
 #define PROGRESS_COPY_TUPLES_PROCESSED 2
 #define PROGRESS_COPY_TUPLES_EXCLUDED 3
+#define PROGRESS_COPY_COMMAND 4
+
+/* Commands of PROGRESS_COPY_COMMAND */
+#define PROGRESS_COPY_COMMAND_FROM 1
+#define PROGRESS_COPY_COMMAND_TO 2
 
 #endif
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 970f6909c2..63b5e33083 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1948,6 +1948,11 @@ pg_stat_progress_copy| SELECT s.pid,
     s.datid,
     d.datname,
     s.relid,
+        CASE s.param5
+            WHEN 1 THEN 'COPY FROM'::text
+            WHEN 2 THEN 'COPY TO'::text
+            ELSE NULL::text
+        END AS command,
     s.param1 AS bytes_processed,
     s.param2 AS bytes_total,
     s.param3 AS tuples_processed,
-- 
2.20.1