diff options
| -rw-r--r-- | src/backend/storage/ipc/procarray.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index bf2f4dbed2d..908f62d37e2 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -799,10 +799,21 @@ ProcArrayApplyRecoveryInfo(RunningTransactions running) qsort(xids, nxids, sizeof(TransactionId), xidComparator); /* - * Add the sorted snapshot into KnownAssignedXids + * Add the sorted snapshot into KnownAssignedXids. The running-xacts + * snapshot may include duplicated xids because of prepared + * transactions, so ignore them. */ for (i = 0; i < nxids; i++) + { + if (i > 0 && TransactionIdEquals(xids[i - 1], xids[i])) + { + elog(DEBUG1, + "found duplicated transaction %u for KnownAssignedXids insertion", + xids[i]); + continue; + } KnownAssignedXidsAdd(xids[i], xids[i], true); + } KnownAssignedXidsDisplay(trace_recovery(DEBUG3)); } @@ -1898,7 +1909,8 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc) * GetRunningTransactionData -- returns information about running transactions. * * Similar to GetSnapshotData but returns more information. We include - * all PGXACTs with an assigned TransactionId, even VACUUM processes. + * all PGXACTs with an assigned TransactionId, even VACUUM processes and + * prepared transactions. * * We acquire XidGenLock and ProcArrayLock, but the caller is responsible for * releasing them. Acquiring XidGenLock ensures that no new XIDs enter the proc @@ -1912,6 +1924,11 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc) * This is never executed during recovery so there is no need to look at * KnownAssignedXids. * + * Dummy PGXACTs from prepared transaction are included, meaning that this + * may return entries with duplicated TransactionId values coming from + * transaction finishing to prepare. Nothing is done about duplicated + * entries here to not hold on ProcArrayLock more than necessary. + * * We don't worry about updating other counters, we want to keep this as * simple as possible and leave GetSnapshotData() as the primary code for * that bookkeeping. |