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Do not wait running-xacts recprd from primary of checkoint doesn't contain oldestActiveXid

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Konstantin Knizhnik
2024-07-24 15:33:18 +03:00
parent bb2a3f9b02
commit 6e6b33cbfd
1 changed files with 31 additions and 16 deletions
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47
pgxn/neon/neon.c
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@@ -366,23 +366,38 @@ RestoreRunningXactsFromClog(CheckPoint *checkpoint, TransactionId **xids, int *n
if (!TransactionIdIsValid(checkpoint->oldestActiveXid))
{
elog(LOG, "cannot restore running-xacts from CLOG because oldestActiveXid is not set");
goto fail;
}
if (running_xacts_overflow_policy == OP_WAIT)
goto fail;
/*
* We will scan the CLOG starting from the oldest active XID.
*
* In some corner cases, the oldestActiveXid from the last checkpoint
* might already have been truncated from the CLOG. That is,
* oldestActiveXid might be older than oldestXid. That's possible because
* oldestActiveXid is only updated at checkpoints. After the last
* checkpoint, the oldest transaction might have committed, and the CLOG
* might also have been already truncated. So if oldestActiveXid is older
* than oldestXid, start at oldestXid instead. (Otherwise we'd try to
* access CLOG segments that have already been truncated away.)
*/
from = TransactionIdPrecedes(checkpoint->oldestXid, checkpoint->oldestActiveXid)
? checkpoint->oldestActiveXid : checkpoint->oldestXid;
if (TransactionIdIsValid(checkpoint->oldestXid))
{
/* Scan from the beginning of CLOG */
from = checkpoint->oldestXid;
}
else
{
/* Assume that there are no active transactions except prepared */
PrescanPreparedTransactions(xids, nxids);
return true;
}
}
else
{
/*
* We will scan the CLOG starting from the oldest active XID.
*
* In some corner cases, the oldestActiveXid from the last checkpoint
* might already have been truncated from the CLOG. That is,
* oldestActiveXid might be older than oldestXid. That's possible because
* oldestActiveXid is only updated at checkpoints. After the last
* checkpoint, the oldest transaction might have committed, and the CLOG
* might also have been already truncated. So if oldestActiveXid is older
* than oldestXid, start at oldestXid instead. (Otherwise we'd try to
* access CLOG segments that have already been truncated away.)
*/
from = TransactionIdPrecedes(checkpoint->oldestXid, checkpoint->oldestActiveXid)
? checkpoint->oldestActiveXid : checkpoint->oldestXid;
}
till = XidFromFullTransactionId(checkpoint->nextXid);
/*