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Create a new HeapTupleSatisfiesVacuum() routine in tqual.c that embodies the

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validity checking rules for VACUUM.  Make some other rearrangements of the
VACUUM code to allow more code to be shared between full and lazy VACUUM.
Minor code cleanups and added comments for TransactionId manipulations.
This commit is contained in:
Tom Lane
2001-07-12 04:11:13 +00:00
parent eaafc9d66c
commit b9f3a929ee
14 changed files with 643 additions and 567 deletions
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27
src/backend/access/transam/varsup.c
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@@ -6,7 +6,7 @@
* Copyright (c) 2000, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.40 2001/05/25 15:45:32 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.41 2001/07/12 04:11:13 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -18,8 +18,7 @@
#include "storage/proc.h"
/* Number of XIDs and OIDs to prefetch (preallocate) per XLOG write */
#define VAR_XID_PREFETCH 1024
/* Number of OIDs to prefetch (preallocate) per XLOG write */
#define VAR_OID_PREFETCH 8192
/* Spinlocks for serializing generation of XIDs and OIDs, respectively */
@@ -29,10 +28,13 @@ SPINLOCK OidGenLockId;
/* pointer to "variable cache" in shared memory (set up by shmem.c) */
VariableCache ShmemVariableCache = NULL;
/*
* Allocate the next XID for my new transaction.
*/
void
GetNewTransactionId(TransactionId *xid)
{
/*
* During bootstrap initialization, we return the special bootstrap
* transaction id.
@@ -49,10 +51,22 @@ GetNewTransactionId(TransactionId *xid)
(ShmemVariableCache->nextXid)++;
SpinRelease(XidGenLockId);
/*
* Must set MyProc->xid before releasing XidGenLock. This ensures that
* when GetSnapshotData calls ReadNewTransactionId, all active XIDs
* before the returned value of nextXid are already present in the shared
* PROC array. Else we have a race condition.
*
* XXX by storing xid into MyProc without acquiring SInvalLock, we are
* relying on fetch/store of an xid to be atomic, else other backends
* might see a partially-set xid here. But holding both locks at once
* would be a nasty concurrency hit (and at this writing, could cause a
* deadlock against GetSnapshotData). So for now, assume atomicity.
*/
if (MyProc != (PROC *) NULL)
MyProc->xid = *xid;
SpinRelease(XidGenLockId);
}
/*
@@ -61,7 +75,6 @@ GetNewTransactionId(TransactionId *xid)
void
ReadNewTransactionId(TransactionId *xid)
{
/*
* During bootstrap initialization, we return the special bootstrap
* transaction id.