Add support for more progress reporting in COPY

The command (TO or FROM), its type (file, pipe, program or callback),
and the number of tuples excluded by a WHERE clause in COPY FROM are
added to the progress reporting already available.

The column "lines_processed" is renamed to "tuples_processed" to
disambiguate the meaning of this column in the cases of CSV and BINARY
COPY and to be more consistent with the other catalog progress views.

Bump catalog version, again.

Author: Matthias van de Meent
Reviewed-by: Michael Paquier, Justin Pryzby, Bharath Rupireddy, Josef
Šimánek, Tomas Vondra
Discussion: https://postgr.es/m/CAEze2WiOcgdH4aQA8NtZq-4dgvnJzp8PohdeKchPkhMY-jWZXA@mail.gmail.com

doc/src/sgml/monitoring.sgml

@@ -6531,8 +6531,33 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid,
        <structfield>relid</structfield> <type>oid</type>
       </para>
       <para>
-       OID of the table on which the <command>COPY</command> command is executed.
+       OID of the table on which the <command>COPY</command> command is
-       It is set to 0 if copying from a <command>SELECT</command> query.
+       executed. It is set to <literal>0</literal> if copying from a
+       <command>SELECT</command> query.
+      </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>type</structfield> <type>text</type>
+      </para>
+      <para>
+       The io type that the data is read from or written to:
+       <literal>FILE</literal>, <literal>PROGRAM</literal>,
+       <literal>PIPE</literal> (for <command>COPY FROM STDIN</command> and
+       <command>COPY TO STDOUT</command>), or <literal>CALLBACK</literal>
+       (used for example during the initial table synchronization in
+       logical replication).
       </para></entry>
      </row>
 
@@ -6551,16 +6576,26 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid,
       </para>
       <para>
        Size of source file for <command>COPY FROM</command> command in bytes.
-       It is set to 0 if not available.
+       It is set to <literal>0</literal> if not available.
       </para></entry>
      </row>
 
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
-       <structfield>lines_processed</structfield> <type>bigint</type>
+       <structfield>tuples_processed</structfield> <type>bigint</type>
       </para>
       <para>
-       Number of lines already processed by <command>COPY</command> command.
+       Number of tuples already processed by <command>COPY</command> command.
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>tuples_excluded</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of tuples not processed because they were excluded by the
+       <command>WHERE</command> clause of the <command>COPY</command> command.
       </para></entry>
      </row>
     </tbody>

src/backend/catalog/system_views.sql

@@ -1129,9 +1129,18 @@ 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,
+        CASE S.param6 WHEN 1 THEN 'FILE'
+                      WHEN 2 THEN 'PROGRAM'
+                      WHEN 3 THEN 'PIPE'
+                      WHEN 4 THEN 'CALLBACK'
+                      END AS "type",
         S.param1 AS bytes_processed,
         S.param2 AS bytes_total,
-        S.param3 AS lines_processed
+        S.param3 AS tuples_processed,
+        S.param4 AS tuples_excluded
     FROM pg_stat_get_progress_info('COPY') AS S
         LEFT JOIN pg_database D ON S.datid = D.oid;
 

src/backend/commands/copyfrom.c

@@ -539,7 +539,8 @@ CopyFrom(CopyFromState cstate)
 	BulkInsertState bistate = NULL;
 	CopyInsertMethod insertMethod;
 	CopyMultiInsertInfo multiInsertInfo = {0};	/* pacify compiler */
-	uint64		processed = 0;
+	int64		processed = 0;
+	int64		excluded = 0;
 	bool		has_before_insert_row_trig;
 	bool		has_instead_insert_row_trig;
 	bool		leafpart_use_multi_insert = false;
@@ -869,8 +870,16 @@ CopyFrom(CopyFromState cstate)
 			econtext->ecxt_scantuple = myslot;
 			/* Skip items that don't match COPY's WHERE clause */
 			if (!ExecQual(cstate->qualexpr, econtext))
+			{
+				/*
+				 * Report that this tuple was filtered out by the WHERE
+				 * clause.
+				 */
+				pgstat_progress_update_param(PROGRESS_COPY_TUPLES_EXCLUDED,
+											 ++excluded);
 				continue;
 			}
+		}
 
 		/* Determine the partition to insert the tuple into */
 		if (proute)
@@ -1107,7 +1116,8 @@ CopyFrom(CopyFromState cstate)
 			 * for counting tuples inserted by an INSERT command.  Update
 			 * progress of the COPY command as well.
 			 */
-			pgstat_progress_update_param(PROGRESS_COPY_LINES_PROCESSED, ++processed);
+			pgstat_progress_update_param(PROGRESS_COPY_TUPLES_PROCESSED,
+										 ++processed);
 		}
 	}
 
@@ -1193,6 +1203,16 @@ BeginCopyFrom(ParseState *pstate,
 	ExprState **defexprs;
 	MemoryContext oldcontext;
 	bool		volatile_defexprs;
+	const int	progress_cols[] = {
+		PROGRESS_COPY_COMMAND,
+		PROGRESS_COPY_TYPE,
+		PROGRESS_COPY_BYTES_TOTAL
+	};
+	int64		progress_vals[] = {
+		PROGRESS_COPY_COMMAND_FROM,
+		0,
+		0
+	};
 
 	/* Allocate workspace and zero all fields */
 	cstate = (CopyFromStateData *) palloc0(sizeof(CopyFromStateData));
@@ -1430,11 +1450,13 @@ BeginCopyFrom(ParseState *pstate,
 
 	if (data_source_cb)
 	{
+		progress_vals[1] = PROGRESS_COPY_TYPE_CALLBACK;
 		cstate->copy_src = COPY_CALLBACK;
 		cstate->data_source_cb = data_source_cb;
 	}
 	else if (pipe)
 	{
+		progress_vals[1] = PROGRESS_COPY_TYPE_PIPE;
 		Assert(!is_program);	/* the grammar does not allow this */
 		if (whereToSendOutput == DestRemote)
 			ReceiveCopyBegin(cstate);
@@ -1447,6 +1469,7 @@ BeginCopyFrom(ParseState *pstate,
 
 		if (cstate->is_program)
 		{
+			progress_vals[1] = PROGRESS_COPY_TYPE_PROGRAM;
 			cstate->copy_file = OpenPipeStream(cstate->filename, PG_BINARY_R);
 			if (cstate->copy_file == NULL)
 				ereport(ERROR,
@@ -1458,6 +1481,7 @@ BeginCopyFrom(ParseState *pstate,
 		{
 			struct stat st;
 
+			progress_vals[1] = PROGRESS_COPY_TYPE_FILE;
 			cstate->copy_file = AllocateFile(cstate->filename, PG_BINARY_R);
 			if (cstate->copy_file == NULL)
 			{
@@ -1484,10 +1508,12 @@ BeginCopyFrom(ParseState *pstate,
 						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
 						 errmsg("\"%s\" is a directory", cstate->filename)));
 
-			pgstat_progress_update_param(PROGRESS_COPY_BYTES_TOTAL, st.st_size);
+			progress_vals[2] = st.st_size;
 		}
 	}
 
+	pgstat_progress_update_multi_param(3, progress_cols, progress_vals);
+
 	if (cstate->opts.binary)
 	{
 		/* Read and verify binary header */

src/backend/commands/copyto.c

@@ -353,6 +353,14 @@ BeginCopyTo(ParseState *pstate,
 	TupleDesc	tupDesc;
 	int			num_phys_attrs;
 	MemoryContext oldcontext;
+	const int	progress_cols[] = {
+		PROGRESS_COPY_COMMAND,
+		PROGRESS_COPY_TYPE
+	};
+	int64		progress_vals[] = {
+		PROGRESS_COPY_COMMAND_TO,
+		0
+	};
 
 	if (rel != NULL && rel->rd_rel->relkind != RELKIND_RELATION)
 	{
@@ -659,6 +667,8 @@ BeginCopyTo(ParseState *pstate,
 
 	if (pipe)
 	{
+		progress_vals[1] = PROGRESS_COPY_TYPE_PIPE;
+
 		Assert(!is_program);	/* the grammar does not allow this */
 		if (whereToSendOutput != DestRemote)
 			cstate->copy_file = stdout;
@@ -670,6 +680,7 @@ BeginCopyTo(ParseState *pstate,
 
 		if (is_program)
 		{
+			progress_vals[1] = PROGRESS_COPY_TYPE_PROGRAM;
 			cstate->copy_file = OpenPipeStream(cstate->filename, PG_BINARY_W);
 			if (cstate->copy_file == NULL)
 				ereport(ERROR,
@@ -682,6 +693,8 @@ BeginCopyTo(ParseState *pstate,
 			mode_t		oumask; /* Pre-existing umask value */
 			struct stat st;
 
+			progress_vals[1] = PROGRESS_COPY_TYPE_FILE;
+
 			/*
 			 * Prevent write to relative path ... too easy to shoot oneself in
 			 * the foot by overwriting a database file ...
@@ -731,6 +744,8 @@ BeginCopyTo(ParseState *pstate,
 	/* initialize progress */
 	pgstat_progress_start_command(PROGRESS_COMMAND_COPY,
 								  cstate->rel ? RelationGetRelid(cstate->rel) : InvalidOid);
+	pgstat_progress_update_multi_param(2, progress_cols, progress_vals);
+
 	cstate->bytes_processed = 0;
 
 	MemoryContextSwitchTo(oldcontext);
@@ -881,8 +896,12 @@ DoCopyTo(CopyToState cstate)
 			/* Format and send the data */
 			CopyOneRowTo(cstate, slot);
 
-			/* Increment amount of processed tuples and update the progress */
+			/*
-			pgstat_progress_update_param(PROGRESS_COPY_LINES_PROCESSED, ++processed);
+			 * Increment the number of processed tuples, and report the
+			 * progress.
+			 */
+			pgstat_progress_update_param(PROGRESS_COPY_TUPLES_PROCESSED,
+										 ++processed);
 		}
 
 		ExecDropSingleTupleTableSlot(slot);
@@ -1251,8 +1270,9 @@ copy_dest_receive(TupleTableSlot *slot, DestReceiver *self)
 	/* Send the data */
 	CopyOneRowTo(cstate, slot);
 
-	/* Increment amount of processed tuples and update the progress */
+	/* Increment the number of processed tuples, and report the progress */
-	pgstat_progress_update_param(PROGRESS_COPY_LINES_PROCESSED, ++myState->processed);
+	pgstat_progress_update_param(PROGRESS_COPY_TUPLES_PROCESSED,
+								 ++myState->processed);
 
 	return true;
 }

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202103091
+#define CATALOG_VERSION_NO	202103092
 
 #endif

src/include/commands/progress.h

@@ -133,9 +133,22 @@
 #define PROGRESS_BASEBACKUP_PHASE_WAIT_WAL_ARCHIVE		4
 #define PROGRESS_BASEBACKUP_PHASE_TRANSFER_WAL			5
 
-/* Commands of PROGRESS_COPY */
+/* Progress parameters for PROGRESS_COPY */
 #define PROGRESS_COPY_BYTES_PROCESSED 0
 #define PROGRESS_COPY_BYTES_TOTAL 1
-#define PROGRESS_COPY_LINES_PROCESSED 2
+#define PROGRESS_COPY_TUPLES_PROCESSED 2
+#define PROGRESS_COPY_TUPLES_EXCLUDED 3
+#define PROGRESS_COPY_COMMAND 4
+#define PROGRESS_COPY_TYPE 5
+
+/* Commands of COPY (as advertised via PROGRESS_COPY_COMMAND) */
+#define PROGRESS_COPY_COMMAND_FROM 1
+#define PROGRESS_COPY_COMMAND_TO 2
+
+/* Types of COPY commands (as advertised via PROGRESS_COPY_TYPE) */
+#define PROGRESS_COPY_TYPE_FILE 1
+#define PROGRESS_COPY_TYPE_PROGRAM 2
+#define PROGRESS_COPY_TYPE_PIPE 3
+#define PROGRESS_COPY_TYPE_CALLBACK 4
 
 #endif

src/test/regress/expected/rules.out

@@ -1950,9 +1950,22 @@ 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,
+        CASE s.param6
+            WHEN 1 THEN 'FILE'::text
+            WHEN 2 THEN 'PROGRAM'::text
+            WHEN 3 THEN 'PIPE'::text
+            WHEN 4 THEN 'CALLBACK'::text
+            ELSE NULL::text
+        END AS type,
     s.param1 AS bytes_processed,
     s.param2 AS bytes_total,
-    s.param3 AS lines_processed
+    s.param3 AS tuples_processed,
+    s.param4 AS tuples_excluded
    FROM (pg_stat_get_progress_info('COPY'::text) s(pid, datid, relid, param1, param2, param3, param4, param5, param6, param7, param8, param9, param10, param11, param12, param13, param14, param15, param16, param17, param18, param19, param20)
      LEFT JOIN pg_database d ON ((s.datid = d.oid)));
 pg_stat_progress_create_index| SELECT s.pid,