Count buffers dirtied due to hints in pgBufferUsage.shared_blks_dirtied.

robertmhaas · robertmhaas · commit 6a63dda4c2a0 · 2014-03-31T13:29:54.000-04:00
Previously, such buffers weren't counted, with the possible result that
EXPLAIN (BUFFERS) and pg_stat_statements would understate the true
number of blocks dirtied by an SQL statement.

Back-patch to 9.2, where this counter was introduced.

Amit Kapila
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
@@ -2474,6 +2474,7 @@ SetBufferCommitInfoNeedsSave(Buffer buffer)
 		{
 			/* Do vacuum cost accounting */
 			VacuumPageDirty++;
+			pgBufferUsage.shared_blks_dirtied++;
 			if (VacuumCostActive)
 				VacuumCostBalance += VacuumCostPageDirty;
 		}

Original file line number	Diff line number	Diff line change
`@@ -2474,6 +2474,7 @@ SetBufferCommitInfoNeedsSave(Buffer buffer)`
`2474`	`2474`	`{`
`2475`	`2475`	`/* Do vacuum cost accounting */`
`2476`	`2476`	`VacuumPageDirty++;`
	`2477`	`+ pgBufferUsage.shared_blks_dirtied++;`
`2477`	`2478`	`if (VacuumCostActive)`
`2478`	`2479`	`VacuumCostBalance += VacuumCostPageDirty;`
`2479`	`2480`	`}`