Remove unnecessary segment number calculation after wal_removed invalidation of replication slots
Hi,
It looks like there's an unnecessary segment number calculation after
InvalidateObsoleteReplicationSlots in CreateCheckPoint and
CreateRestartPoint. Since none of RedoRecPtr, _logSegNo and
wal_segment_size are changed by the slot invalidation code [1]Assertions like the following won't fail with make check-world proving InvalidateObsoleteReplicationSlots doesn't change them at all., the
recalculation of
_logSegNo with XLByteToSeg seems unnecessary.
I've attached a patch to fix this.
[1]: Assertions like the following won't fail with make check-world proving InvalidateObsoleteReplicationSlots doesn't change them at all.
proving InvalidateObsoleteReplicationSlots doesn't change them at all.
XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
KeepLogSeg(recptr, &_logSegNo);
+ _logSegNo_saved = _logSegNo;
+ RedoRecPtr_saved = RedoRecPtr;
if (InvalidateObsoleteReplicationSlots(RS_INVAL_WAL_REMOVED,
_logSegNo, InvalidOid,
InvalidTransactionId))
{
+ Assert(_logSegNo_saved == _logSegNo);
+ Assert(RedoRecPtr_saved == RedoRecPtr);--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
Attachments:
v1-0001-Remove-unnecessary-seg-no-calculation-after-check.patchapplication/octet-stream; name=v1-0001-Remove-unnecessary-seg-no-calculation-after-check.patchDownload
From 47d0300bb595ba36d29df2f7cc11880a184228f6 Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: Sat, 13 Apr 2024 08:30:59 +0000
Subject: [PATCH v1] Remove unnecessary seg no calculation after check for slot
invalidation.
---
src/backend/access/transam/xlog.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 34a2c71812..66f491a08a 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7248,7 +7248,6 @@ CreateCheckPoint(int flags)
* Some slots have been invalidated; recalculate the old-segment
* horizon, starting again from RedoRecPtr.
*/
- XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
KeepLogSeg(recptr, &_logSegNo);
}
_logSegNo--;
@@ -7700,7 +7699,6 @@ CreateRestartPoint(int flags)
* Some slots have been invalidated; recalculate the old-segment
* horizon, starting again from RedoRecPtr.
*/
- XLByteToSeg(RedoRecPtr, _logSegNo, wal_segment_size);
KeepLogSeg(endptr, &_logSegNo);
}
_logSegNo--;
--
2.34.1