diff options
Diffstat (limited to 'src/backend/access/transam/xlog.c')
| -rw-r--r-- | src/backend/access/transam/xlog.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 975eac0c22b..25809961028 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -7903,6 +7903,7 @@ CreateCheckPoint(int flags) uint32 freespace; XLogRecPtr PriorRedoPtr; XLogRecPtr curInsert; + XLogRecPtr prevPtr; VirtualTransactionId *vxids; int nvxids; @@ -7988,6 +7989,7 @@ CreateCheckPoint(int flags) */ WALInsertLockAcquireExclusive(); curInsert = XLogBytePosToRecPtr(Insert->CurrBytePos); + prevPtr = XLogBytePosToRecPtr(Insert->PrevBytePos); /* * If this isn't a shutdown or forced checkpoint, and we have not inserted @@ -7999,17 +8001,17 @@ CreateCheckPoint(int flags) * (Perhaps it'd make even more sense to checkpoint only when the previous * checkpoint record is in a different xlog page?) * - * We have to make two tests to determine that nothing has happened since - * the start of the last checkpoint: current insertion point must match - * the end of the last checkpoint record, and its redo pointer must point - * to itself. + * If the previous checkpoint crossed a WAL segment, however, we create + * the checkpoint anyway, to have the latest checkpoint fully contained in + * the new segment. This is for a little bit of extra robustness: it's + * better if you don't need to keep two WAL segments around to recover the + * checkpoint. */ if ((flags & (CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_END_OF_RECOVERY | CHECKPOINT_FORCE)) == 0) { - if (curInsert == ControlFile->checkPoint + - MAXALIGN(SizeOfXLogRecord + sizeof(CheckPoint)) && - ControlFile->checkPoint == ControlFile->checkPointCopy.redo) + if (prevPtr == ControlFile->checkPointCopy.redo && + prevPtr / XLOG_SEG_SIZE == curInsert / XLOG_SEG_SIZE) { WALInsertLockRelease(); LWLockRelease(CheckpointLock); |