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Change overly strict Assert in TransactionGroupUpdateXidStatus.

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This Assert thought that an overflowed transaction can never get registered
for the group update.  But that is not true, because even when the number
of children for a transaction got reduced, the overflow flag is not
changed.  And, for group update, we only care about the current number of
children for a transaction that is being committed.

Based on comments by Andres Freund, remove a redundant Assert in
TransactionIdSetPageStatus as we already had a static Assert for the same
condition a few lines earlier.

Reported-by: Vignesh C
Author: Dilip Kumar
Reviewed-by: Amit Kapila
Backpatch-through: 11
Discussion: https://postgr.es/m/CAFiTN-s5=uJw-Z6JC9gcqtBSjXsrHnU63PXBrA=pnBjqnkm5UA@mail.gmail.com
This commit is contained in:
Amit Kapila 2019-12-12 11:51:30 +05:30
parent 2cf51809b1
commit fc68a10b57
1 changed files with 3 additions and 10 deletions
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13
src/backend/access/transam/clog.c
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@ -299,13 +299,6 @@ TransactionIdSetPageStatus(TransactionId xid, int nsubxids,
memcmp(subxids, MyProc->subxids.xids,
nsubxids * sizeof(TransactionId)) == 0)
{
/*
* We don't try to do group update optimization if a process has
* overflowed the subxids array in its PGPROC, since in that case we
* don't have a complete list of XIDs for it.
*/
Assert(THRESHOLD_SUBTRANS_CLOG_OPT <= PGPROC_MAX_CACHED_SUBXIDS);
/*
* If we can immediately acquire CLogControlLock, we update the status
* of our own XID and release the lock. If not, try use group XID
@ -520,10 +513,10 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status,
PGXACT *pgxact = &ProcGlobal->allPgXact[nextidx];
/*
* Overflowed transactions should not use group XID status update
* mechanism.
* Transactions with more than THRESHOLD_SUBTRANS_CLOG_OPT sub-XIDs
* should not use group XID status update mechanism.
*/
Assert(!pgxact->overflowed);
Assert(pgxact->nxids <= THRESHOLD_SUBTRANS_CLOG_OPT);
TransactionIdSetPageStatusInternal(proc->clogGroupMemberXid,
pgxact->nxids,