*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.156 2003/09/25 06:57:56 petere Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.157 2003/10/01 21:30:52 tgl Exp $
*
*
* INTERFACE ROUTINES
* NB: do not call this directly unless you are prepared to deal with
* concurrent-update conditions. Use simple_heap_delete instead.
*
+ * relation - table to be modified
+ * tid - TID of tuple to be deleted
+ * ctid - output parameter, used only for failure case (see below)
+ * cid - delete command ID to use in verifying tuple visibility
+ * crosscheck - if not SnapshotAny, also check tuple against this
+ * wait - true if should wait for any conflicting update to commit/abort
+ *
* Normal, successful return value is HeapTupleMayBeUpdated, which
* actually means we did delete it. Failure return codes are
* HeapTupleSelfUpdated, HeapTupleUpdated, or HeapTupleBeingUpdated
- * (the last only possible if wait == false).
+ * (the last only possible if wait == false). On a failure return,
+ * *ctid is set to the ctid link of the target tuple (possibly a later
+ * version of the row).
*/
int
heap_delete(Relation relation, ItemPointer tid,
- ItemPointer ctid, CommandId cid, bool wait)
+ ItemPointer ctid, CommandId cid, Snapshot crosscheck, bool wait)
{
ItemId lp;
HeapTupleData tp;
tp.t_tableOid = relation->rd_id;
l1:
- result = HeapTupleSatisfiesUpdate(&tp, cid);
+ result = HeapTupleSatisfiesUpdate(tp.t_data, cid);
if (result == HeapTupleInvisible)
{
else
result = HeapTupleUpdated;
}
+
+ if (crosscheck != SnapshotAny && result == HeapTupleMayBeUpdated)
+ {
+ /* Perform additional check for serializable RI updates */
+ if (!HeapTupleSatisfiesSnapshot(tp.t_data, crosscheck))
+ result = HeapTupleUpdated;
+ }
+
if (result != HeapTupleMayBeUpdated)
{
Assert(result == HeapTupleSelfUpdated ||
result = heap_delete(relation, tid,
&ctid,
- GetCurrentCommandId(),
+ GetCurrentCommandId(), SnapshotAny,
true /* wait for commit */);
switch (result)
{
* NB: do not call this directly unless you are prepared to deal with
* concurrent-update conditions. Use simple_heap_update instead.
*
+ * relation - table to be modified
+ * otid - TID of old tuple to be replaced
+ * newtup - newly constructed tuple data to store
+ * ctid - output parameter, used only for failure case (see below)
+ * cid - update command ID to use in verifying old tuple visibility
+ * crosscheck - if not SnapshotAny, also check old tuple against this
+ * wait - true if should wait for any conflicting update to commit/abort
+ *
* Normal, successful return value is HeapTupleMayBeUpdated, which
* actually means we *did* update it. Failure return codes are
* HeapTupleSelfUpdated, HeapTupleUpdated, or HeapTupleBeingUpdated
- * (the last only possible if wait == false).
+ * (the last only possible if wait == false). On a failure return,
+ * *ctid is set to the ctid link of the old tuple (possibly a later
+ * version of the row).
+ * On success, newtup->t_self is set to the TID where the new tuple
+ * was inserted.
*/
int
heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
- ItemPointer ctid, CommandId cid, bool wait)
+ ItemPointer ctid, CommandId cid, Snapshot crosscheck, bool wait)
{
ItemId lp;
HeapTupleData oldtup;
*/
l2:
- result = HeapTupleSatisfiesUpdate(&oldtup, cid);
+ result = HeapTupleSatisfiesUpdate(oldtup.t_data, cid);
if (result == HeapTupleInvisible)
{
else
result = HeapTupleUpdated;
}
+
+ if (crosscheck != SnapshotAny && result == HeapTupleMayBeUpdated)
+ {
+ /* Perform additional check for serializable RI updates */
+ if (!HeapTupleSatisfiesSnapshot(oldtup.t_data, crosscheck))
+ result = HeapTupleUpdated;
+ }
+
if (result != HeapTupleMayBeUpdated)
{
Assert(result == HeapTupleSelfUpdated ||
result = heap_update(relation, otid, tup,
&ctid,
- GetCurrentCommandId(),
+ GetCurrentCommandId(), SnapshotAny,
true /* wait for commit */);
switch (result)
{
tuple->t_len = ItemIdGetLength(lp);
l3:
- result = HeapTupleSatisfiesUpdate(tuple, cid);
+ result = HeapTupleSatisfiesUpdate(tuple->t_data, cid);
if (result == HeapTupleInvisible)
{
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/commands/async.c,v 1.100 2003/09/15 23:33:39 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/async.c,v 1.101 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
*/
result = heap_update(lRel, &lTuple->t_self, rTuple,
&ctid,
- GetCurrentCommandId(),
+ GetCurrentCommandId(), SnapshotAny,
false /* no wait for commit */);
switch (result)
{
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.219 2003/09/25 18:58:35 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.220 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* field of the QueryDesc is filled in to describe the tuples that will be
* returned, and the internal fields (estate and planstate) are set up.
*
- * If useSnapshotNow is true, run the query with SnapshotNow time qual rules
- * instead of the normal use of QuerySnapshot.
+ * If useCurrentSnapshot is true, run the query with the latest available
+ * snapshot, instead of the normal QuerySnapshot. Also, if it's an update
+ * or delete query, check that the rows to be updated or deleted would be
+ * visible to the normal QuerySnapshot. (This is a special-case behavior
+ * needed for referential integrity updates in serializable transactions.
+ * We must check all currently-committed rows, but we want to throw a
+ * can't-serialize error if any rows that would need updates would not be
+ * visible under the normal serializable snapshot.)
*
* If explainOnly is true, we are not actually intending to run the plan,
* only to set up for EXPLAIN; so skip unwanted side-effects.
* ----------------------------------------------------------------
*/
void
-ExecutorStart(QueryDesc *queryDesc, bool useSnapshotNow, bool explainOnly)
+ExecutorStart(QueryDesc *queryDesc, bool useCurrentSnapshot, bool explainOnly)
{
EState *estate;
MemoryContext oldcontext;
* the life of this query, even if it outlives the current command and
* current snapshot.
*/
- if (useSnapshotNow)
+ if (useCurrentSnapshot)
{
- estate->es_snapshot = SnapshotNow;
- estate->es_snapshot_cid = GetCurrentCommandId();
+ /* RI update/delete query --- must use an up-to-date snapshot */
+ estate->es_snapshot = CopyCurrentSnapshot();
+ /* crosscheck updates/deletes against transaction snapshot */
+ estate->es_crosscheck_snapshot = CopyQuerySnapshot();
}
else
{
+ /* normal query --- use query snapshot, no crosscheck */
estate->es_snapshot = CopyQuerySnapshot();
- estate->es_snapshot_cid = estate->es_snapshot->curcid;
+ estate->es_crosscheck_snapshot = SnapshotAny;
}
/*
tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
test = heap_mark4update(erm->relation, &tuple, &buffer,
- estate->es_snapshot_cid);
+ estate->es_snapshot->curcid);
ReleaseBuffer(buffer);
switch (test)
{
if (estate->es_into_relation_descriptor != NULL)
{
heap_insert(estate->es_into_relation_descriptor, tuple,
- estate->es_snapshot_cid);
+ estate->es_snapshot->curcid);
IncrAppended();
}
* insert the tuple
*/
newId = heap_insert(resultRelationDesc, tuple,
- estate->es_snapshot_cid);
+ estate->es_snapshot->curcid);
IncrAppended();
(estate->es_processed)++;
bool dodelete;
dodelete = ExecBRDeleteTriggers(estate, resultRelInfo, tupleid,
- estate->es_snapshot_cid);
+ estate->es_snapshot->curcid);
if (!dodelete) /* "do nothing" */
return;
ldelete:;
result = heap_delete(resultRelationDesc, tupleid,
&ctid,
- estate->es_snapshot_cid,
+ estate->es_snapshot->curcid,
+ estate->es_crosscheck_snapshot,
true /* wait for commit */);
switch (result)
{
newtuple = ExecBRUpdateTriggers(estate, resultRelInfo,
tupleid, tuple,
- estate->es_snapshot_cid);
+ estate->es_snapshot->curcid);
if (newtuple == NULL) /* "do nothing" */
return;
*/
result = heap_update(resultRelationDesc, tupleid, tuple,
&ctid,
- estate->es_snapshot_cid,
+ estate->es_snapshot->curcid,
+ estate->es_crosscheck_snapshot,
true /* wait for commit */);
switch (result)
{
*/
epqstate->es_direction = ForwardScanDirection;
epqstate->es_snapshot = estate->es_snapshot;
- epqstate->es_snapshot_cid = estate->es_snapshot_cid;
+ epqstate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
epqstate->es_range_table = estate->es_range_table;
epqstate->es_result_relations = estate->es_result_relations;
epqstate->es_num_result_relations = estate->es_num_result_relations;
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.105 2003/09/25 18:58:35 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.106 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
*/
estate->es_direction = ForwardScanDirection;
estate->es_snapshot = SnapshotNow;
- estate->es_snapshot_cid = FirstCommandId;
+ estate->es_crosscheck_snapshot = SnapshotAny; /* means no crosscheck */
estate->es_range_table = NIL;
estate->es_result_relations = NULL;
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.57 2003/09/25 18:58:35 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.58 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
sp_estate->es_tupleTable =
ExecCreateTupleTable(ExecCountSlotsNode(subplan->plan) + 10);
sp_estate->es_snapshot = estate->es_snapshot;
- sp_estate->es_snapshot_cid = estate->es_snapshot_cid;
+ sp_estate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
sp_estate->es_instrument = estate->es_instrument;
/*
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/executor/nodeSubqueryscan.c,v 1.21 2003/09/25 18:58:35 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/executor/nodeSubqueryscan.c,v 1.22 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
sp_estate->es_tupleTable =
ExecCreateTupleTable(ExecCountSlotsNode(node->subplan) + 10);
sp_estate->es_snapshot = estate->es_snapshot;
- sp_estate->es_snapshot_cid = estate->es_snapshot_cid;
+ sp_estate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
sp_estate->es_instrument = estate->es_instrument;
/*
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/executor/spi.c,v 1.106 2003/09/25 18:58:35 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/executor/spi.c,v 1.107 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
static int _SPI_execute(const char *src, int tcount, _SPI_plan *plan);
static int _SPI_pquery(QueryDesc *queryDesc, bool runit,
- bool useSnapshotNow, int tcount);
+ bool useCurrentSnapshot, int tcount);
static int _SPI_execute_plan(_SPI_plan *plan,
Datum *Values, const char *Nulls,
- bool useSnapshotNow, int tcount);
+ bool useCurrentSnapshot, int tcount);
static void _SPI_cursor_operation(Portal portal, bool forward, int count,
DestReceiver *dest);
}
/*
- * SPI_execp_now -- identical to SPI_execp, except that we use SnapshotNow
- * instead of the normal QuerySnapshot. This is currently not documented
- * in spi.sgml because it is only intended for use by RI triggers.
+ * SPI_execp_current -- identical to SPI_execp, except that we expose the
+ * Executor option to use a current snapshot instead of the normal
+ * QuerySnapshot. This is currently not documented in spi.sgml because
+ * it is only intended for use by RI triggers.
*/
int
-SPI_execp_now(void *plan, Datum *Values, const char *Nulls, int tcount)
+SPI_execp_current(void *plan, Datum *Values, const char *Nulls,
+ bool useCurrentSnapshot, int tcount)
{
int res;
if (res < 0)
return res;
- res = _SPI_execute_plan((_SPI_plan *) plan, Values, Nulls, true, tcount);
+ res = _SPI_execute_plan((_SPI_plan *) plan, Values, Nulls,
+ useCurrentSnapshot, tcount);
_SPI_end_call(true);
return res;
static int
_SPI_execute_plan(_SPI_plan *plan, Datum *Values, const char *Nulls,
- bool useSnapshotNow, int tcount)
+ bool useCurrentSnapshot, int tcount)
{
List *query_list_list = plan->qtlist;
List *plan_list = plan->ptlist;
{
qdesc = CreateQueryDesc(queryTree, planTree, dest,
paramLI, false);
- res = _SPI_pquery(qdesc, true, useSnapshotNow,
+ res = _SPI_pquery(qdesc, true, useCurrentSnapshot,
queryTree->canSetTag ? tcount : 0);
if (res < 0)
return res;
}
static int
-_SPI_pquery(QueryDesc *queryDesc, bool runit, bool useSnapshotNow, int tcount)
+_SPI_pquery(QueryDesc *queryDesc, bool runit,
+ bool useCurrentSnapshot, int tcount)
{
int operation = queryDesc->operation;
int res;
ResetUsage();
#endif
- ExecutorStart(queryDesc, useSnapshotNow, false);
+ ExecutorStart(queryDesc, useCurrentSnapshot, false);
ExecutorRun(queryDesc, ForwardScanDirection, (long) tcount);
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinval.c,v 1.60 2003/09/24 18:54:01 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinval.c,v 1.61 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* lastBackend would be sufficient. But it seems better to do the
* malloc while not holding the lock, so we can't look at lastBackend.
*
- * if (snapshot->xip != NULL) no need to free and reallocate xip;
- *
- * We can reuse the old xip array, because MaxBackends does not change at
- * runtime.
+ * This does open a possibility for avoiding repeated malloc/free:
+ * since MaxBackends does not change at runtime, we can simply reuse
+ * the previous xip array if any. (This relies on the fact that all
+ * calls pass static SnapshotData structs.)
*/
if (snapshot->xip == NULL)
{
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
*
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.60 2003/09/29 00:05:25 petere Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/ri_triggers.c,v 1.61 2003/10/01 21:30:52 tgl Exp $
*
* ----------
*/
static bool ri_PerformCheck(RI_QueryKey *qkey, void *qplan,
Relation fk_rel, Relation pk_rel,
HeapTuple old_tuple, HeapTuple new_tuple,
+ bool detectNewRows,
int expect_OK, const char *constrname);
static void ri_ExtractValues(RI_QueryKey *qkey, int key_idx,
Relation rel, HeapTuple tuple,
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
NULL, NULL,
+ false,
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
NULL, new_row,
+ false,
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
result = ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
+ true, /* treat like update */
SPI_OK_SELECT, NULL);
if (SPI_finish() != SPI_OK_FINISH)
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
+ true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
+ true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
+ true, /* must detect new rows */
SPI_OK_DELETE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, new_row,
+ true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
+ true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
+ true, /* must detect new rows */
SPI_OK_SELECT,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
+ true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
+ true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
+ true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(&qkey, qplan,
fk_rel, pk_rel,
old_row, NULL,
+ true, /* must detect new rows */
SPI_OK_UPDATE,
tgargs[RI_CONSTRAINT_NAME_ARGNO]);
ri_PerformCheck(RI_QueryKey *qkey, void *qplan,
Relation fk_rel, Relation pk_rel,
HeapTuple old_tuple, HeapTuple new_tuple,
+ bool detectNewRows,
int expect_OK, const char *constrname)
{
Relation query_rel,
source_rel;
int key_idx;
+ bool useCurrentSnapshot;
int limit;
int spi_result;
AclId save_uid;
vals, nulls);
}
- /* Switch to proper UID to perform check as */
- save_uid = GetUserId();
- SetUserId(RelationGetForm(query_rel)->relowner);
+ /*
+ * In READ COMMITTED mode, we just need to make sure the regular query
+ * snapshot is up-to-date, and we will see all rows that could be
+ * interesting. In SERIALIZABLE mode, we can't update the regular query
+ * snapshot. If the caller passes detectNewRows == false then it's okay
+ * to do the query with the transaction snapshot; otherwise we tell the
+ * executor to force a current snapshot (and error out if it finds any
+ * rows under current snapshot that wouldn't be visible per the
+ * transaction snapshot).
+ */
+ if (XactIsoLevel == XACT_SERIALIZABLE)
+ {
+ useCurrentSnapshot = detectNewRows;
+ }
+ else
+ {
+ SetQuerySnapshot();
+ useCurrentSnapshot = false;
+ }
/*
* If this is a select query (e.g., for a 'no action' or 'restrict'
*/
limit = (expect_OK == SPI_OK_SELECT) ? 1 : 0;
- /*
- * Run the plan, using SnapshotNow time qual rules so that we can see
- * all committed tuples, even those committed after our own transaction
- * or query started.
- */
- spi_result = SPI_execp_now(qplan, vals, nulls, limit);
+ /* Switch to proper UID to perform check as */
+ save_uid = GetUserId();
+ SetUserId(RelationGetForm(query_rel)->relowner);
+
+ /* Finally we can run the query. */
+ spi_result = SPI_execp_current(qplan, vals, nulls,
+ useCurrentSnapshot, limit);
/* Restore UID */
SetUserId(save_uid);
/* Check result */
if (spi_result < 0)
- elog(ERROR, "SPI_execp_now returned %d", spi_result);
+ elog(ERROR, "SPI_execp_current returned %d", spi_result);
if (expect_OK >= 0 && spi_result != expect_OK)
ri_ReportViolation(qkey, constrname ? constrname : "",
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/time/tqual.c,v 1.69 2003/09/25 18:58:35 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/time/tqual.c,v 1.70 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "storage/sinval.h"
#include "utils/tqual.h"
-
-static SnapshotData SnapshotDirtyData;
-Snapshot SnapshotDirty = &SnapshotDirtyData;
-
+/*
+ * The SnapshotData structs are static to simplify memory allocation
+ * (see the hack in GetSnapshotData to avoid repeated malloc/free).
+ */
static SnapshotData QuerySnapshotData;
static SnapshotData SerializableSnapshotData;
+static SnapshotData CurrentSnapshotData;
+static SnapshotData SnapshotDirtyData;
+
+/* Externally visible pointers to valid snapshots: */
Snapshot QuerySnapshot = NULL;
Snapshot SerializableSnapshot = NULL;
+Snapshot SnapshotDirty = &SnapshotDirtyData;
/* These are updated by GetSnapshotData: */
TransactionId RecentXmin = InvalidTransactionId;
* CurrentCommandId.
*/
int
-HeapTupleSatisfiesUpdate(HeapTuple htuple, CommandId curcid)
+HeapTupleSatisfiesUpdate(HeapTupleHeader tuple, CommandId curcid)
{
- HeapTupleHeader tuple = htuple->t_data;
-
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return snapshot;
}
+/*
+ * CopyCurrentSnapshot
+ * Make a snapshot that is up-to-date as of the current instant,
+ * and return a copy.
+ *
+ * The copy is palloc'd in the current memory context.
+ */
+Snapshot
+CopyCurrentSnapshot(void)
+{
+ Snapshot currentSnapshot;
+ Snapshot snapshot;
+
+ if (QuerySnapshot == NULL) /* should not be first call in xact */
+ elog(ERROR, "no snapshot has been set");
+
+ /* Update the static struct */
+ currentSnapshot = GetSnapshotData(&CurrentSnapshotData, false);
+ currentSnapshot->curcid = GetCurrentCommandId();
+
+ /* Make a copy */
+ snapshot = (Snapshot) palloc(sizeof(SnapshotData));
+ memcpy(snapshot, currentSnapshot, sizeof(SnapshotData));
+ if (snapshot->xcnt > 0)
+ {
+ snapshot->xip = (TransactionId *)
+ palloc(snapshot->xcnt * sizeof(TransactionId));
+ memcpy(snapshot->xip, currentSnapshot->xip,
+ snapshot->xcnt * sizeof(TransactionId));
+ }
+ else
+ snapshot->xip = NULL;
+
+ return snapshot;
+}
+
/*
* FreeXactSnapshot
* Free snapshot(s) at end of transaction.
FreeXactSnapshot(void)
{
/*
- * We do not free(QuerySnapshot->xip); or
- * free(SerializableSnapshot->xip); they will be reused soon
+ * We do not free the xip arrays for the snapshot structs;
+ * they will be reused soon. So this is now just a state
+ * change to prevent outside callers from accessing the snapshots.
*/
QuerySnapshot = NULL;
SerializableSnapshot = NULL;
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: heapam.h,v 1.84 2003/09/15 23:33:43 tgl Exp $
+ * $Id: heapam.h,v 1.85 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
extern Oid heap_insert(Relation relation, HeapTuple tup, CommandId cid);
extern int heap_delete(Relation relation, ItemPointer tid, ItemPointer ctid,
- CommandId cid, bool wait);
+ CommandId cid, Snapshot crosscheck, bool wait);
extern int heap_update(Relation relation, ItemPointer otid, HeapTuple tup,
- ItemPointer ctid, CommandId cid, bool wait);
+ ItemPointer ctid, CommandId cid, Snapshot crosscheck, bool wait);
extern int heap_mark4update(Relation relation, HeapTuple tup,
Buffer *userbuf, CommandId cid);
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: executor.h,v 1.101 2003/09/25 18:58:35 tgl Exp $
+ * $Id: executor.h,v 1.102 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
/*
* prototypes from functions in execMain.c
*/
-extern void ExecutorStart(QueryDesc *queryDesc, bool useSnapshotNow,
+extern void ExecutorStart(QueryDesc *queryDesc, bool useCurrentSnapshot,
bool explainOnly);
extern TupleTableSlot *ExecutorRun(QueryDesc *queryDesc,
ScanDirection direction, long count);
*
* spi.h
*
- * $Id: spi.h,v 1.38 2003/09/25 18:58:36 tgl Exp $
+ * $Id: spi.h,v 1.39 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
extern int SPI_exec(const char *src, int tcount);
extern int SPI_execp(void *plan, Datum *values, const char *Nulls,
int tcount);
-extern int SPI_execp_now(void *plan, Datum *values, const char *Nulls,
- int tcount);
+extern int SPI_execp_current(void *plan, Datum *values, const char *Nulls,
+ bool useCurrentSnapshot, int tcount);
extern void *SPI_prepare(const char *src, int nargs, Oid *argtypes);
extern void *SPI_saveplan(void *plan);
extern int SPI_freeplan(void *plan);
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: execnodes.h,v 1.106 2003/09/25 18:58:36 tgl Exp $
+ * $Id: execnodes.h,v 1.107 2003/10/01 21:30:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
/* Basic state for all query types: */
ScanDirection es_direction; /* current scan direction */
Snapshot es_snapshot; /* time qual to use */
- CommandId es_snapshot_cid; /* CommandId component of time qual */
+ Snapshot es_crosscheck_snapshot; /* crosscheck time qual for RI */
List *es_range_table; /* List of RangeTableEntrys */
/* Info about target table for insert/update/delete queries: */
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: tqual.h,v 1.47 2003/09/25 18:58:36 tgl Exp $
+ * $Id: tqual.h,v 1.48 2003/10/01 21:30:53 tgl Exp $
*
*-------------------------------------------------------------------------
*/
extern bool HeapTupleSatisfiesToast(HeapTupleHeader tuple);
extern bool HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple,
Snapshot snapshot);
-extern int HeapTupleSatisfiesUpdate(HeapTuple tuple,
+extern int HeapTupleSatisfiesUpdate(HeapTupleHeader tuple,
CommandId curcid);
extern HTSV_Result HeapTupleSatisfiesVacuum(HeapTupleHeader tuple,
TransactionId OldestXmin);
extern Snapshot GetSnapshotData(Snapshot snapshot, bool serializable);
extern void SetQuerySnapshot(void);
extern Snapshot CopyQuerySnapshot(void);
+extern Snapshot CopyCurrentSnapshot(void);
extern void FreeXactSnapshot(void);
#endif /* TQUAL_H */
projects / postgresql.git / commitdiff