diff options
Diffstat (limited to 'src/backend/storage/ipc/sinval.c')
| -rw-r--r-- | src/backend/storage/ipc/sinval.c | 42 |
1 files changed, 27 insertions, 15 deletions
diff --git a/src/backend/storage/ipc/sinval.c b/src/backend/storage/ipc/sinval.c index 985577c4a6c..1d43b1ead44 100644 --- a/src/backend/storage/ipc/sinval.c +++ b/src/backend/storage/ipc/sinval.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinval.c,v 1.39 2001/08/25 18:52:42 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinval.c,v 1.40 2001/08/26 16:56:00 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -20,6 +20,8 @@ #include "storage/sinval.h" #include "storage/sinvaladt.h" #include "utils/tqual.h" +#include "miscadmin.h" + SPINLOCK SInvalLock = (SPINLOCK) NULL; @@ -210,17 +212,23 @@ TransactionIdIsInProgress(TransactionId xid) } /* - * GetXmaxRecent -- returns oldest transaction that was running - * when all current transaction were started. - * It's used by vacuum to decide what deleted - * tuples must be preserved in a table. + * GetOldestXmin -- returns oldest transaction that was running + * when any current transaction was started. + * + * If allDbs is TRUE then all backends are considered; if allDbs is FALSE + * then only backends running in my own database are considered. * - * Note: we include all currently running xids in the set of considered xids. + * This is used by VACUUM to decide which deleted tuples must be preserved + * in a table. allDbs = TRUE is needed for shared relations, but allDbs = + * FALSE is sufficient for non-shared relations, since only backends in my + * own database could ever see the tuples in them. + * + * Note: we include the currently running xids in the set of considered xids. * This ensures that if a just-started xact has not yet set its snapshot, * when it does set the snapshot it cannot set xmin less than what we compute. */ -void -GetXmaxRecent(TransactionId *XmaxRecent) +TransactionId +GetOldestXmin(bool allDbs) { SISeg *segP = shmInvalBuffer; ProcState *stateP = segP->procState; @@ -238,24 +246,28 @@ GetXmaxRecent(TransactionId *XmaxRecent) if (pOffset != INVALID_OFFSET) { PROC *proc = (PROC *) MAKE_PTR(pOffset); - /* Fetch xid just once - see GetNewTransactionId */ - TransactionId xid = proc->xid; - if (TransactionIdIsNormal(xid)) + if (allDbs || proc->databaseId == MyDatabaseId) { - if (TransactionIdPrecedes(xid, result)) - result = xid; - xid = proc->xmin; + /* Fetch xid just once - see GetNewTransactionId */ + TransactionId xid = proc->xid; + if (TransactionIdIsNormal(xid)) + { if (TransactionIdPrecedes(xid, result)) result = xid; + xid = proc->xmin; + if (TransactionIdIsNormal(xid)) + if (TransactionIdPrecedes(xid, result)) + result = xid; + } } } } SpinRelease(SInvalLock); - *XmaxRecent = result; + return result; } /*---------- |