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Replace implementation of pg_log as a relation accessed through the

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buffer manager with 'pg_clog', a specialized access method modeled
on pg_xlog.  This simplifies startup (don't need to play games to
open pg_log; among other things, OverrideTransactionSystem goes away),
should improve performance a little, and opens the door to recycling
commit log space by removing no-longer-needed segments of the commit
log.  Actual recycling is not there yet, but I felt I should commit
this part separately since it'd still be useful if we chose not to
do transaction ID wraparound.
This commit is contained in:
Tom Lane
2001-08-25 18:52:43 +00:00
parent 4699d81dc9
commit 2589735da0
39 changed files with 1248 additions and 1128 deletions
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160
src/backend/access/transam/xact.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.108 2001/07/16 22:43:33 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.109 2001/08/25 18:52:41 tgl Exp $
*
* NOTES
* Transaction aborts can now occur two ways:
@ -228,22 +228,6 @@ int CommitSiblings = 5; /* number of concurrent xacts needed to
static void (*_RollbackFunc) (void *) = NULL;
static void *_RollbackData = NULL;
/* ----------------
* info returned when the system is disabled
*
* Apparently a lot of this code is inherited from other prototype systems.
*
* For DisabledStartTime, use a symbolic value to make the relationships clearer.
* The old value of 1073741823 corresponds to a date in y2004, which is coming closer
* every day. It appears that if we return a value guaranteed larger than
* any real time associated with a transaction then comparisons in other
* modules will still be correct. Let's use BIG_ABSTIME for this. tgl 2/14/97
* ----------------
*/
static CommandId DisabledCommandId = (CommandId) -1;
static AbsoluteTime DisabledStartTime = (AbsoluteTime) BIG_ABSTIME;
/* ----------------
* catalog creation transaction bootstrapping flag.
* This should be eliminated and added to the transaction
@ -309,8 +293,6 @@ IsTransactionState(void)
return true;
case TRANS_ABORT:
return true;
case TRANS_DISABLED:
return false;
}
/*
@ -339,44 +321,9 @@ IsAbortedTransactionBlockState(void)
return false;
}
/* --------------------------------
* OverrideTransactionSystem
*
* This is used to temporarily disable the transaction
* processing system in order to do initialization of
* the transaction system data structures and relations
* themselves.
* --------------------------------
*/
static int SavedTransactionState;
void
OverrideTransactionSystem(bool flag)
{
TransactionState s = CurrentTransactionState;
if (flag == true)
{
if (s->state == TRANS_DISABLED)
return;
SavedTransactionState = s->state;
s->state = TRANS_DISABLED;
}
else
{
if (s->state != TRANS_DISABLED)
return;
s->state = SavedTransactionState;
}
}
/* --------------------------------
* GetCurrentTransactionId
*
* This returns the id of the current transaction, or
* the id of the "disabled" transaction.
* --------------------------------
*/
TransactionId
@ -384,16 +331,6 @@ GetCurrentTransactionId(void)
{
TransactionState s = CurrentTransactionState;
/*
* if the transaction system is disabled, we return the special
* "disabled" transaction id.
*/
if (s->state == TRANS_DISABLED)
return DisabledTransactionId;
/*
* otherwise return the current transaction id.
*/
return s->transactionIdData;
}
@ -407,13 +344,6 @@ GetCurrentCommandId(void)
{
TransactionState s = CurrentTransactionState;
/*
* if the transaction system is disabled, we return the special
* "disabled" command id.
*/
if (s->state == TRANS_DISABLED)
return DisabledCommandId;
return s->commandId;
}
@ -422,13 +352,6 @@ GetScanCommandId(void)
{
TransactionState s = CurrentTransactionState;
/*
* if the transaction system is disabled, we return the special
* "disabled" command id.
*/
if (s->state == TRANS_DISABLED)
return DisabledCommandId;
return s->scanCommandId;
}
@ -442,13 +365,6 @@ GetCurrentTransactionStartTime(void)
{
TransactionState s = CurrentTransactionState;
/*
* if the transaction system is disabled, we return the special
* "disabled" starting time.
*/
if (s->state == TRANS_DISABLED)
return DisabledStartTime;
return s->startTime;
}
@ -523,16 +439,6 @@ SetScanCommandId(CommandId savedId)
CurrentTransactionStateData.scanCommandId = savedId;
}
/* ----------------------------------------------------------------
* initialization stuff
* ----------------------------------------------------------------
*/
void
InitializeTransactionSystem(void)
{
InitializeTransactionLog();
}
/* ----------------------------------------------------------------
* StartTransaction stuff
* ----------------------------------------------------------------
@ -617,15 +523,19 @@ AtStart_Memory(void)
* --------------------------------
*/
void
RecordTransactionCommit()
RecordTransactionCommit(void)
{
TransactionId xid;
bool leak;
xid = GetCurrentTransactionId();
leak = BufferPoolCheckLeak();
xid = GetCurrentTransactionId();
/*
* We needn't write anything in xlog or clog if the transaction was
* read-only, which we check by testing if it made any xlog entries.
*/
if (MyLastRecPtr.xrecoff != 0)
{
XLogRecData rdata;
@ -673,6 +583,7 @@ RecordTransactionCommit()
/* Break the chain of back-links in the XLOG records I output */
MyLastRecPtr.xrecoff = 0;
/* Mark the transaction committed in clog */
TransactionIdCommit(xid);
END_CRIT_SECTION();
@ -765,7 +676,10 @@ RecordTransactionAbort(void)
TransactionId xid = GetCurrentTransactionId();
/*
* Double check here is to catch case that we aborted partway through
* We needn't write anything in xlog or clog if the transaction was
* read-only, which we check by testing if it made any xlog entries.
*
* Extra check here is to catch case that we aborted partway through
* RecordTransactionCommit ...
*/
if (MyLastRecPtr.xrecoff != 0 && !TransactionIdDidCommit(xid))
@ -782,8 +696,17 @@ RecordTransactionAbort(void)
START_CRIT_SECTION();
/*
* SHOULD SAVE ARRAY OF RELFILENODE-s TO DROP
*/
recptr = XLogInsert(RM_XACT_ID, XLOG_XACT_ABORT, &rdata);
/*
* There's no need for XLogFlush here, since the default assumption
* would be that we aborted, anyway.
*/
/* Mark the transaction aborted in clog */
TransactionIdAbort(xid);
END_CRIT_SECTION();
@ -913,7 +836,7 @@ StartTransaction(void)
* fix to a communications problem, and we keep having to deal with it
* here. We should fix the comm channel code. mao 080891
*/
if (s->state == TRANS_DISABLED || s->state == TRANS_INPROGRESS)
if (s->state == TRANS_INPROGRESS)
return;
/*
@ -927,7 +850,7 @@ StartTransaction(void)
/*
* generate a new transaction id
*/
GetNewTransactionId(&(s->transactionIdData));
s->transactionIdData = GetNewTransactionId();
XactLockTableInsert(s->transactionIdData);
@ -984,11 +907,8 @@ CommitTransaction(void)
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
return;
if (s->state != TRANS_INPROGRESS)
elog(NOTICE, "CommitTransaction and not in in-progress state ");
elog(NOTICE, "CommitTransaction and not in in-progress state");
/*
* Tell the trigger manager that this transaction is about to be
@ -1109,12 +1029,6 @@ AbortTransaction(void)
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
{
RESUME_INTERRUPTS();
return;
}
if (s->state != TRANS_INPROGRESS)
elog(NOTICE, "AbortTransaction and not in in-progress state");
@ -1138,7 +1052,7 @@ AbortTransaction(void)
CloseSequences();
AtEOXact_portals();
/* Advertise the fact that we aborted in pg_log. */
/* Advertise the fact that we aborted in pg_clog. */
RecordTransactionAbort();
/*
@ -1191,9 +1105,6 @@ CleanupTransaction(void)
{
TransactionState s = CurrentTransactionState;
if (s->state == TRANS_DISABLED)
return;
/*
* State should still be TRANS_ABORT from AbortTransaction().
*/
@ -1464,9 +1375,6 @@ BeginTransactionBlock(void)
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
return;
if (s->blockState != TBLOCK_DEFAULT)
elog(NOTICE, "BEGIN: already a transaction in progress");
@ -1498,9 +1406,6 @@ EndTransactionBlock(void)
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
return;
if (s->blockState == TBLOCK_INPROGRESS)
{
@ -1552,9 +1457,6 @@ AbortTransactionBlock(void)
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
return;
if (s->blockState == TBLOCK_INPROGRESS)
{
@ -1591,12 +1493,6 @@ UserAbortTransactionBlock(void)
{
TransactionState s = CurrentTransactionState;
/*
* check the current transaction state
*/
if (s->state == TRANS_DISABLED)
return;
/*
* if the transaction has already been automatically aborted with an
* error, and the user subsequently types 'abort', allow it. (the
@ -1665,7 +1561,6 @@ AbortOutOfAnyTransaction(void)
CleanupTransaction();
break;
case TRANS_DEFAULT:
case TRANS_DISABLED:
/* Not in a transaction, do nothing */
break;
}
@ -1700,7 +1595,10 @@ xact_redo(XLogRecPtr lsn, XLogRecord *record)
/* SHOULD REMOVE FILES OF ALL DROPPED RELATIONS */
}
else if (info == XLOG_XACT_ABORT)
{
TransactionIdAbort(record->xl_xid);
/* SHOULD REMOVE FILES OF ALL FAILED-TO-BE-CREATED RELATIONS */
}
else
elog(STOP, "xact_redo: unknown op code %u", info);
}