Fix incremental and archive backup removal on delete command

Michael Paquier · Michael Paquier · commit 342496e331ea · 2014-01-17T22:02:27.000+09:00
The previous algorithm was smart enough to remove full backups older
than the given number of generations, but not enough to remove
incremental and archive backups. This resulted in keeping in the backup
list a set of incremental and archive backups older than the latest
full backup allowed. As it is useless to keep them, the deletion
algorithm is made smarter to take that into account and remove all of
them cleanly only when necessary.
diff --git a/delete.c b/delete.c
@@ -80,7 +80,6 @@ pgBackupDelete(int keep_generations, int keep_days)
 	int		backup_num;
 	time_t	days_threshold = current.start_time - (keep_days * 60 * 60 * 24);
 
-
 	if (verbose)
 	{
 		char generations_str[100];
@@ -116,20 +115,21 @@ pgBackupDelete(int keep_generations, int keep_days)
 	backup_num = 0;
 	for (i = 0; i < parray_num(backup_list); i++)
 	{
-		pgBackup *backup = (pgBackup *)parray_get(backup_list, i);
+		pgBackup   *backup = (pgBackup *) parray_get(backup_list, i);
+		int			backup_num_evaluate = backup_num;
 
 		elog(LOG, "%s() %lu", __FUNCTION__, backup->start_time);
 
 		/*
 		 * When a validate full backup was found, we can delete the
-		 * backup that is older than it.
+		 * backup that is older than it using the number of generations.
 		 */
-		if (backup->backup_mode >= BACKUP_MODE_FULL &&
+		if (backup->backup_mode == BACKUP_MODE_FULL &&
 			backup->status == BACKUP_STATUS_OK)
 			backup_num++;
 
 		/* Evaluate if this backup is eligible for removal */
-		if (backup_num <= keep_generations &&
+		if (backup_num_evaluate + 1 <= keep_generations &&
 			keep_generations != KEEP_INFINITE)
 		{
 			/* Do not include the latest full backup in this count */
