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authorPeter Geoghegan2023-01-24 23:15:33 +0000
committerPeter Geoghegan2023-01-24 23:15:33 +0000
commit8f8f11593258d04e9a58365865f7daf123e24bb1 (patch)
treedf2ba1b8e9ebf368cb26f058de7566cc8f1b00a4
parent1249371632db9d97786edfb3d58c3e89e75b9519 (diff)
Update more obsolete multixact.c comments.
Update some remaining comments in multixact.c that still described SLRU truncation as happening in the checkpointer, rather than during VACUUM. Follow-up to commit 5212d447. Shi yu, with tweaks by me. Author: Shi yu <[email protected]> Discussion: https://postgr.es/m/OSZPR01MB631066BF246F8F74E83222FCFDC69@OSZPR01MB6310.jpnprd01.prod.outlook.com
-rw-r--r--src/backend/access/transam/multixact.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index e75e1fdf74..fe6698d5ff 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -261,7 +261,7 @@ typedef struct MultiXactStateData
* we compute it (using nextMXact if none are valid). Each backend is
* required not to attempt to access any SLRU data for MultiXactIds older
* than its own OldestVisibleMXactId[] setting; this is necessary because
- * the checkpointer could truncate away such data at any instant.
+ * the relevant SLRU data can be concurrently truncated away.
*
* The oldest valid value among all of the OldestMemberMXactId[] and
* OldestVisibleMXactId[] entries is considered by vacuum as the earliest
@@ -669,8 +669,8 @@ MultiXactIdSetOldestMember(void)
*
* We set the OldestVisibleMXactId for a given transaction the first time
* it's going to inspect any MultiXactId. Once we have set this, we are
- * guaranteed that the checkpointer won't truncate off SLRU data for
- * MultiXactIds at or after our OldestVisibleMXactId.
+ * guaranteed that SLRU data for MultiXactIds >= our own OldestVisibleMXactId
+ * won't be truncated away.
*
* The value to set is the oldest of nextMXact and all the valid per-backend
* OldestMemberMXactId[] entries. Because of the locking we do, we can be