Count buffers dirtied due to hints in pgBufferUsage.shared_blks_dirtied.

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
index 9b0283fa518bdc1a28c30017143af01be1110eff..c60158d675f4cf16976fb3db1eac3545297c81fe 100644 (file)
--- 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;
                }