Report NULL as total backup size if it's not estimated.

Previously 0 was reported in pg_stat_progress_basebackup.total_backup
if the total backup size was not estimated. Per discussion, our consensus
is that NULL is better choise as the value in total_backup in that case.
So this commit makes pg_stat_progress_basebackup view report NULL
in total_backup column if the estimation is disabled.

Bump catversion.

Author: Fujii Masao
Reviewed-by: Amit Langote, Magnus Hagander, Alvaro Herrera
Discussion: https://postgr.es/m/CABUevExnhOD89zBDuPvfAAh243RzNpwCPEWNLtMYpKHMB8gbAQ@mail.gmail.com

1 files changed, 17 insertions, 2 deletions

diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c
index 806d013108d..a2e28b064cd 100644
--- a/src/backend/replication/basebackup.c
+++ b/src/backend/replication/basebackup.c
@@ -123,7 +123,10 @@ static long long int total_checksum_failures;
 /* Do not verify checksums. */
 static bool noverify_checksums = false;
 
-/* Total amount of backup data that will be streamed */
+/*
+ * Total amount of backup data that will be streamed.
+ * -1 means that the size is not estimated.
+ */
 static int64 backup_total = 0;
 
 /* Amount of backup data already streamed */
@@ -258,6 +261,18 @@ perform_base_backup(basebackup_options *opt)
 	backup_streamed = 0;
 	pgstat_progress_start_command(PROGRESS_COMMAND_BASEBACKUP, InvalidOid);
 
+	/*
+	 * If the estimation of the total backup size is disabled, make the
+	 * backup_total column in the view return NULL by setting the parameter to
+	 * -1.
+	 */
+	if (!opt->progress)
+	{
+		backup_total = -1;
+		pgstat_progress_update_param(PROGRESS_BASEBACKUP_BACKUP_TOTAL,
+									 backup_total);
+	}
+
 	datadirpathlen = strlen(DataDir);
 
 	backup_started_in_recovery = RecoveryInProgress();
@@ -1842,7 +1857,7 @@ update_basebackup_progress(int64 delta)
 	 * will always be wrong if WAL is included), but that's better than having
 	 * the done column be bigger than the total.
 	 */
-	if (backup_total > 0 && backup_streamed > backup_total)
+	if (backup_total > -1 && backup_streamed > backup_total)
 	{
 		backup_total = backup_streamed;
 		val[nparam++] = backup_total;