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Fix very old bug which made tuples changed/inserted by a commnd

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visible to command itself (so we had multiple update of updated tuples,
etc).
This commit is contained in:
Vadim B. Mikheev
1997-08-29 09:05:25 +00:00
parent e06099c607
commit 3152996ffb
3 changed files with 63 additions and 11 deletions
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42
src/backend/access/transam/xact.c
View File

@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.12 1997/08/19 21:30:19 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.13 1997/08/29 09:02:11 vadim Exp $
*
* NOTES
* Transaction aborts can now occur two ways:
@@ -377,6 +377,22 @@ GetCurrentCommandId()
return s->commandId;
}
CommandId
GetScanCommandId()
{
TransactionState s = CurrentTransactionState;
/* ----------------
* if the transaction system is disabled, we return
* the special "disabled" command id.
* ----------------
*/
if (s->state == TRANS_DISABLED)
return (CommandId) DisabledCommandId;
return s->scanCommandId;
}
/* --------------------------------
* GetCurrentTransactionStartTime
@@ -432,6 +448,18 @@ CommandIdIsCurrentCommandId(CommandId cid)
(cid == s->commandId) ? true : false;
}
bool
CommandIdGEScanCommandId(CommandId cid)
{
TransactionState s = CurrentTransactionState;
if (AMI_OVERRIDE)
return false;
return
(cid >= s->scanCommandId) ? true : false;
}
/* --------------------------------
* ClearCommandIdCounterOverflowFlag
@@ -458,11 +486,22 @@ CommandCounterIncrement()
elog(WARN, "You may only have 65535 commands per transaction");
}
CurrentTransactionStateData.scanCommandId =
CurrentTransactionStateData.commandId;
/* make cache changes visible to me */
AtCommit_Cache();
AtStart_Cache();
}
void
SetScanCommandId (CommandId savedId)
{
CurrentTransactionStateData.scanCommandId = savedId;
}
/* ----------------------------------------------------------------
* initialization stuff
* ----------------------------------------------------------------
@@ -757,6 +796,7 @@ StartTransaction()
* ----------------
*/
s->commandId = FirstCommandId;
s->scanCommandId = FirstCommandId;
s->startTime = GetCurrentAbsoluteTime();
/* ----------------

24
src/backend/utils/time/tqual.c
View File

@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/time/tqual.c,v 1.3 1997/08/19 21:36:12 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/time/tqual.c,v 1.4 1997/08/29 09:04:54 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@@ -580,6 +580,13 @@ HeapTupleSatisfiesItself(HeapTuple tuple)
* (Xmax is not committed && the row was deleted by another transaction
* Xmax != my-transaction)))) that has not been committed
*
* XXX
* CommandId stuff didn't work properly if one used SQL-functions in
* UPDATE/INSERT(fromSELECT)/DELETE scans: SQL-funcs call
* CommandCounterIncrement and made tuples changed/inserted by
* current command visible to command itself (so we had multiple
* update of updated tuples, etc). - vadim 08/29/97
*
* mao says 17 march 1993: the tests in this routine are correct;
* if you think they're not, you're wrong, and you should think
* about it again. i know, it happened to me. we don't need to
@@ -615,13 +622,13 @@ HeapTupleSatisfiesNow(HeapTuple tuple)
if (!AbsoluteTimeIsBackwardCompatiblyValid(tuple->t_tmin)) {
if (TransactionIdIsCurrentTransactionId((TransactionId)tuple->t_xmin)
&& CommandIdIsCurrentCommandId(tuple->t_cmin)) {
&& CommandIdGEScanCommandId(tuple->t_cmin)) {
return (false);
}
if (TransactionIdIsCurrentTransactionId((TransactionId)tuple->t_xmin)
&& !CommandIdIsCurrentCommandId(tuple->t_cmin)) {
&& !CommandIdGEScanCommandId(tuple->t_cmin)) {
if (!TransactionIdIsValid((TransactionId)tuple->t_xmax)) {
return (true);
@@ -629,7 +636,7 @@ HeapTupleSatisfiesNow(HeapTuple tuple)
Assert(TransactionIdIsCurrentTransactionId((TransactionId)tuple->t_xmax));
if (CommandIdIsCurrentCommandId(tuple->t_cmax)) {
if (CommandIdGEScanCommandId(tuple->t_cmax)) {
return (true);
}
}
@@ -813,13 +820,13 @@ HeapTupleSatisfiesUpperUnboundedInternalTimeQual(HeapTuple tuple,
if (!AbsoluteTimeIsBackwardCompatiblyValid(tuple->t_tmin)) {
if (TransactionIdIsCurrentTransactionId((TransactionId)tuple->t_xmin) &&
CommandIdIsCurrentCommandId(tuple->t_cmin)) {
CommandIdGEScanCommandId(tuple->t_cmin)) {
return (false);
}
if (TransactionIdIsCurrentTransactionId((TransactionId)tuple->t_xmin) &&
!CommandIdIsCurrentCommandId(tuple->t_cmin)) {
!CommandIdGEScanCommandId(tuple->t_cmin)) {
if (!TransactionIdIsValid((TransactionId)tuple->t_xmax)) {
return (true);
@@ -827,7 +834,7 @@ HeapTupleSatisfiesUpperUnboundedInternalTimeQual(HeapTuple tuple,
Assert(TransactionIdIsCurrentTransactionId((TransactionId)tuple->t_xmax));
return ((bool) !CommandIdIsCurrentCommandId(tuple->t_cmax));
return ((bool) !CommandIdGEScanCommandId(tuple->t_cmax));
}
if (!TransactionIdDidCommit((TransactionId)tuple->t_xmin)) {
@@ -849,7 +856,8 @@ HeapTupleSatisfiesUpperUnboundedInternalTimeQual(HeapTuple tuple,
}
if (TransactionIdIsCurrentTransactionId((TransactionId)tuple->t_xmax)) {
return (CommandIdIsCurrentCommandId(tuple->t_cmin));
return (CommandIdGEScanCommandId(tuple->t_cmin));
/* it looks like error ^^^^ */
}
if (!TransactionIdDidCommit((TransactionId)tuple->t_xmax)) {