/* ----------------------------------------------------------------
* ExecReScanCteScan
*
* Rescans the relation.
* ----------------------------------------------------------------
*/
void
ExecReScanCteScan(CteScanState *node)
{
Tuplestorestate *tuplestorestate = node->leader->cte_table;
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
ExecScanReScan(&node->ss);
if (node->leader == node)
{
/*
* The leader is responsible for clearing the tuplestore if a new scan
* of the underlying CTE is required.
*/
if (node->cteplanstate->chgParam != NULL)
{
tuplestore_clear(tuplestorestate);
node->eof_cte = false;
}
else
{
tuplestore_select_read_pointer(tuplestorestate, node->readptr);
tuplestore_rescan(tuplestorestate);
}
}
else
{
/* Not leader, so just rewind my own pointer */
tuplestore_select_read_pointer(tuplestorestate, node->readptr);
tuplestore_rescan(tuplestorestate);
}
}
/* ----------------------------------------------------------------
* ExecReScanCteScan
*
* Rescans the relation.
* ----------------------------------------------------------------
*/
void
ExecReScanCteScan(CteScanState *node)
{
Tuplestorestate *tuplestorestate = node->leader->cte_table;
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
ExecScanReScan(&node->ss);
/*
* Clear the tuplestore if a new scan of the underlying CTE is required.
* This implicitly resets all the tuplestore's read pointers. Note that
* multiple CTE nodes might redundantly clear the tuplestore; that's OK,
* and not unduly expensive. We'll stop taking this path as soon as
* somebody has attempted to read something from the underlying CTE
* (thereby causing its chgParam to be cleared).
*/
if (node->leader->cteplanstate->chgParam != NULL)
{
tuplestore_clear(tuplestorestate);
node->leader->eof_cte = false;
}
else
{
/*
* Else, just rewind my own pointer. Either the underlying CTE
* doesn't need a rescan (and we can re-read what's in the tuplestore
* now), or somebody else already took care of it.
*/
tuplestore_select_read_pointer(tuplestorestate, node->readptr);
tuplestore_rescan(tuplestorestate);
}
}
/* ----------------------------------------------------------------
* ExecReScanFunctionScan
*
* Rescans the relation.
* ----------------------------------------------------------------
*/
void
ExecReScanFunctionScan(FunctionScanState *node)
{
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
ExecScanReScan(&node->ss);
/*
* If we haven't materialized yet, just return.
*/
if (!node->tuplestorestate)
return;
/*
* Here we have a choice whether to drop the tuplestore (and recompute the
* function outputs) or just rescan it. We must recompute if the
* expression contains parameters, else we rescan. XXX maybe we should
* recompute if the function is volatile?
*/
if (node->ss.ps.chgParam != NULL)
{
tuplestore_end(node->tuplestorestate);
node->tuplestorestate = NULL;
}
else
tuplestore_rescan(node->tuplestorestate);
}
/* ----------------------------------------------------------------
* ExecMaterialReScan
*
* Rescans the materialized relation.
* ----------------------------------------------------------------
*/
void
ExecMaterialReScan(MaterialState *node, ExprContext *exprCtxt)
{
/*
* If we haven't materialized yet, just return. If outerplan' chgParam is
* not NULL then it will be re-scanned by ExecProcNode, else - no reason
* to re-scan it at all.
*/
if (!node->tuplestorestate)
return;
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
/*
* If subnode is to be rescanned then we forget previous stored results;
* we have to re-read the subplan and re-store.
*
* Otherwise we can just rewind and rescan the stored output. The state of
* the subnode does not change.
*/
if (((PlanState *) node)->lefttree->chgParam != NULL)
{
tuplestore_end((Tuplestorestate *) node->tuplestorestate);
node->tuplestorestate = NULL;
node->eof_underlying = false;
}
else
tuplestore_rescan((Tuplestorestate *) node->tuplestorestate);
}
/* ----------------------------------------------------------------
* ExecFunctionReScan
*
* Rescans the relation.
* ----------------------------------------------------------------
*/
void
ExecFunctionReScan(FunctionScanState *node, ExprContext *exprCtxt)
{
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
/*
* If we haven't materialized yet, just return.
*/
if (!node->tuplestorestate)
return;
/*
* Here we have a choice whether to drop the tuplestore (and recompute the
* function outputs) or just rescan it. This should depend on whether the
* function expression contains parameters and/or is marked volatile.
* FIXME soon.
*/
if (node->ss.ps.chgParam != NULL)
{
tuplestore_end(node->tuplestorestate);
node->tuplestorestate = NULL;
}
else
tuplestore_rescan(node->tuplestorestate);
}
/* ----------------------------------------------------------------
* ExecWorkTableScanReScan
*
* Rescans the relation.
* ----------------------------------------------------------------
*/
void
ExecWorkTableScanReScan(WorkTableScanState *node, ExprContext *exprCtxt)
{
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
/* node->ss.ps.ps_TupFromTlist = false; */
/* No need (or way) to rescan if ExecWorkTableScan not called yet */
if (node->rustate)
tuplestore_rescan(node->rustate->working_table);
}
/* ----------------------------------------------------------------
* ExecReScanWorkTableScan
*
* Rescans the relation.
* ----------------------------------------------------------------
*/
void
ExecReScanWorkTableScan(WorkTableScanState *node)
{
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
ExecScanReScan(&node->ss);
/* No need (or way) to rescan if ExecWorkTableScan not called yet */
if (node->rustate)
tuplestore_rescan(node->rustate->working_table);
}
/* ----------------------------------------------------------------
* ExecReScanMaterial
*
* Rescans the materialized relation.
* ----------------------------------------------------------------
*/
void
ExecReScanMaterial(MaterialState *node)
{
PlanState *outerPlan = outerPlanState(node);
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
if (node->eflags != 0)
{
/*
* If we haven't materialized yet, just return. If outerplan's
* chgParam is not NULL then it will be re-scanned by ExecProcNode,
* else no reason to re-scan it at all.
*/
if (!node->tuplestorestate)
return;
/*
* If subnode is to be rescanned then we forget previous stored
* results; we have to re-read the subplan and re-store. Also, if we
* told tuplestore it needn't support rescan, we lose and must
* re-read. (This last should not happen in common cases; else our
* caller lied by not passing EXEC_FLAG_REWIND to us.)
*
* Otherwise we can just rewind and rescan the stored output. The
* state of the subnode does not change.
*/
if (outerPlan->chgParam != NULL ||
(node->eflags & EXEC_FLAG_REWIND) == 0)
{
tuplestore_end(node->tuplestorestate);
node->tuplestorestate = NULL;
if (outerPlan->chgParam == NULL)
ExecReScan(outerPlan);
node->eof_underlying = false;
}
else
tuplestore_rescan(node->tuplestorestate);
}
else
{
/* In this case we are just passing on the subquery's output */
/*
* if chgParam of subnode is not null then plan will be re-scanned by
* first ExecProcNode.
*/
if (outerPlan->chgParam == NULL)
ExecReScan(outerPlan);
node->eof_underlying = false;
}
}
/* ----------------------------------------------------------------
* ExecMaterialReScan
*
* Rescans the materialized relation.
* ----------------------------------------------------------------
*/
void
ExecMaterialReScan(MaterialState *node, ExprContext *exprCtxt)
{
ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
if (node->randomAccess)
{
/*
* If we haven't materialized yet, just return. If outerplan' chgParam
* is not NULL then it will be re-scanned by ExecProcNode, else - no
* reason to re-scan it at all.
*/
if (!node->tuplestorestate)
return;
/*
* If subnode is to be rescanned then we forget previous stored
* results; we have to re-read the subplan and re-store.
*
* Otherwise we can just rewind and rescan the stored output. The
* state of the subnode does not change.
*/
if (((PlanState *) node)->lefttree->chgParam != NULL)
{
tuplestore_end((Tuplestorestate *) node->tuplestorestate);
node->tuplestorestate = NULL;
node->eof_underlying = false;
}
else
tuplestore_rescan((Tuplestorestate *) node->tuplestorestate);
}
else
{
/* In this case we are just passing on the subquery's output */
/*
* if chgParam of subnode is not null then plan will be re-scanned by
* first ExecProcNode.
*/
if (((PlanState *) node)->lefttree->chgParam == NULL)
ExecReScan(((PlanState *) node)->lefttree, exprCtxt);
node->eof_underlying = false;
}
}
extern TuplestoreScanState *
ExecInitTuplestoreScan(TuplestoreScan *node, EState *estate, int eflags)
{
TuplestoreScanState *tss = makeNode(TuplestoreScanState);
tss->ss.ps.plan = (Plan *) node;
tss->ss.ps.state = estate;
tss->ss.ps.ps_ExprContext = CreateExprContext(estate);
ExecInitResultTupleSlot(estate, &tss->ss.ps);
ExecInitScanTupleSlot(estate, &tss->ss);
ExecSetSlotDescriptor(tss->ss.ss_ScanTupleSlot, node->desc);
ExecSetSlotDescriptor(tss->ss.ps.ps_ResultTupleSlot, node->desc);
tss->ss.ps.targetlist = node->scan.plan.targetlist;
tuplestore_rescan(node->store);
return tss;
}
/* ----------------------------------------------------------------
* ExecInitCteScan
* ----------------------------------------------------------------
*/
CteScanState *
ExecInitCteScan(CteScan *node, EState *estate, int eflags)
{
CteScanState *scanstate;
ParamExecData *prmdata;
/* check for unsupported flags */
Assert(!(eflags & EXEC_FLAG_MARK));
/*
* For the moment we have to force the tuplestore to allow REWIND, because
* we might be asked to rescan the CTE even though upper levels didn't
* tell us to be prepared to do it efficiently. Annoying, since this
* prevents truncation of the tuplestore. XXX FIXME
*
* Note: if we are in an EPQ recheck plan tree, it's likely that no access
* to the tuplestore is needed at all, making this even more annoying.
* It's not worth improving that as long as all the read pointers would
* have REWIND anyway, but if we ever improve this logic then that aspect
* should be considered too.
*/
eflags |= EXEC_FLAG_REWIND;
/*
* CteScan should not have any children.
*/
Assert(outerPlan(node) == NULL);
Assert(innerPlan(node) == NULL);
/*
* create new CteScanState for node
*/
scanstate = makeNode(CteScanState);
scanstate->ss.ps.plan = (Plan *) node;
scanstate->ss.ps.state = estate;
scanstate->eflags = eflags;
scanstate->cte_table = NULL;
scanstate->eof_cte = false;
/*
* Find the already-initialized plan for the CTE query.
*/
scanstate->cteplanstate = (PlanState *) list_nth(estate->es_subplanstates,
node->ctePlanId - 1);
/*
* The Param slot associated with the CTE query is used to hold a pointer
* to the CteState of the first CteScan node that initializes for this
* CTE. This node will be the one that holds the shared state for all the
* CTEs, particularly the shared tuplestore.
*/
prmdata = &(estate->es_param_exec_vals[node->cteParam]);
Assert(prmdata->execPlan == NULL);
Assert(!prmdata->isnull);
scanstate->leader = (CteScanState *) DatumGetPointer(prmdata->value);
if (scanstate->leader == NULL)
{
/* I am the leader */
prmdata->value = PointerGetDatum(scanstate);
scanstate->leader = scanstate;
scanstate->cte_table = tuplestore_begin_heap(true, false, work_mem);
tuplestore_set_eflags(scanstate->cte_table, scanstate->eflags);
scanstate->readptr = 0;
}
else
{
/* Not the leader */
Assert(IsA(scanstate->leader, CteScanState));
/* Create my own read pointer, and ensure it is at start */
scanstate->readptr =
tuplestore_alloc_read_pointer(scanstate->leader->cte_table,
scanstate->eflags);
tuplestore_select_read_pointer(scanstate->leader->cte_table,
scanstate->readptr);
tuplestore_rescan(scanstate->leader->cte_table);
}
/*
* Miscellaneous initialization
*
* create expression context for node
*/
ExecAssignExprContext(estate, &scanstate->ss.ps);
/*
* initialize child expressions
*/
scanstate->ss.ps.targetlist = (List *)
ExecInitExpr((Expr *) node->scan.plan.targetlist,
(PlanState *) scanstate);
scanstate->ss.ps.qual = (List *)
ExecInitExpr((Expr *) node->scan.plan.qual,
(PlanState *) scanstate);
/*
* tuple table initialization
*/
ExecInitResultTupleSlot(estate, &scanstate->ss.ps);
ExecInitScanTupleSlot(estate, &scanstate->ss);
/*
* The scan tuple type (ie, the rowtype we expect to find in the work
* table) is the same as the result rowtype of the CTE query.
*/
ExecAssignScanType(&scanstate->ss,
ExecGetResultType(scanstate->cteplanstate));
/*
* Initialize result tuple type and projection info.
*/
ExecAssignResultTypeFromTL(&scanstate->ss.ps);
ExecAssignScanProjectionInfo(&scanstate->ss);
return scanstate;
}
/*
* PersistHoldablePortal
*
* Prepare the specified Portal for access outside of the current
* transaction. When this function returns, all future accesses to the
* portal must be done via the Tuplestore (not by invoking the
* executor).
*/
void
PersistHoldablePortal(Portal portal)
{
QueryDesc *queryDesc = PortalGetQueryDesc(portal);
Portal saveActivePortal;
ResourceOwner saveResourceOwner;
MemoryContext savePortalContext;
MemoryContext oldcxt;
/*
* If we're preserving a holdable portal, we had better be inside the
* transaction that originally created it.
*/
Assert(portal->createSubid != InvalidSubTransactionId);
Assert(queryDesc != NULL);
/*
* Caller must have created the tuplestore already.
*/
Assert(portal->holdContext != NULL);
Assert(portal->holdStore != NULL);
/*
* Before closing down the executor, we must copy the tupdesc into
* long-term memory, since it was created in executor memory.
*/
oldcxt = MemoryContextSwitchTo(portal->holdContext);
portal->tupDesc = CreateTupleDescCopy(portal->tupDesc);
MemoryContextSwitchTo(oldcxt);
/*
* Check for improper portal use, and mark portal active.
*/
if (portal->status != PORTAL_READY)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("portal \"%s\" cannot be run", portal->name)));
portal->status = PORTAL_ACTIVE;
/*
* Set up global portal context pointers.
*/
saveActivePortal = ActivePortal;
saveResourceOwner = CurrentResourceOwner;
savePortalContext = PortalContext;
PG_TRY();
{
ActivePortal = portal;
CurrentResourceOwner = portal->resowner;
PortalContext = PortalGetHeapMemory(portal);
MemoryContextSwitchTo(PortalContext);
PushActiveSnapshot(queryDesc->snapshot);
/*
* Rewind the executor: we need to store the entire result set in the
* tuplestore, so that subsequent backward FETCHs can be processed.
*/
ExecutorRewind(queryDesc);
/*
* Change the destination to output to the tuplestore. Note we tell
* the tuplestore receiver to detoast all data passed through it.
*/
queryDesc->dest = CreateDestReceiver(DestTuplestore);
SetTuplestoreDestReceiverParams(queryDesc->dest,
portal->holdStore,
portal->holdContext,
true);
/* Fetch the result set into the tuplestore */
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
(*queryDesc->dest->rDestroy) (queryDesc->dest);
queryDesc->dest = NULL;
/*
* Now shut down the inner executor.
*/
portal->queryDesc = NULL; /* prevent double shutdown */
/* we do not need AfterTriggerEndQuery() here */
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
/*
* Set the position in the result set: ideally, this could be
* implemented by just skipping straight to the tuple # that we need
* to be at, but the tuplestore API doesn't support that. So we start
* at the beginning of the tuplestore and iterate through it until we
* reach where we need to be. FIXME someday? (Fortunately, the
* typical case is that we're supposed to be at or near the start of
* the result set, so this isn't as bad as it sounds.)
*/
MemoryContextSwitchTo(portal->holdContext);
if (portal->atEnd)
{
/* we can handle this case even if posOverflow */
while (tuplestore_advance(portal->holdStore, true))
/* continue */ ;
}
else
{
long store_pos;
if (portal->posOverflow) /* oops, cannot trust portalPos */
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not reposition held cursor")));
tuplestore_rescan(portal->holdStore);
for (store_pos = 0; store_pos < portal->portalPos; store_pos++)
{
if (!tuplestore_advance(portal->holdStore, true))
elog(ERROR, "unexpected end of tuple stream");
}
}
}
PG_CATCH();
{
/* Uncaught error while executing portal: mark it dead */
portal->status = PORTAL_FAILED;
/* Restore global vars and propagate error */
ActivePortal = saveActivePortal;
CurrentResourceOwner = saveResourceOwner;
PortalContext = savePortalContext;
PG_RE_THROW();
}
PG_END_TRY();
MemoryContextSwitchTo(oldcxt);
/* Mark portal not active */
portal->status = PORTAL_READY;
ActivePortal = saveActivePortal;
CurrentResourceOwner = saveResourceOwner;
PortalContext = savePortalContext;
PopActiveSnapshot();
/*
* We can now release any subsidiary memory of the portal's heap context;
* we'll never use it again. The executor already dropped its context,
* but this will clean up anything that glommed onto the portal's heap via
* PortalContext.
*/
MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
}
/*
* PersistHoldablePortal
*
* Prepare the specified Portal for access outside of the current
* transaction. When this function returns, all future accesses to the
* portal must be done via the Tuplestore (not by invoking the
* executor).
*/
void
PersistHoldablePortal(Portal portal)
{
QueryDesc *queryDesc = PortalGetQueryDesc(portal);
Portal saveActivePortal;
ResourceOwner saveResourceOwner;
MemoryContext savePortalContext;
MemoryContext oldcxt;
/*
* If we're preserving a holdable portal, we had better be inside the
* transaction that originally created it.
*/
Assert(portal->createSubid != InvalidSubTransactionId);
Assert(queryDesc != NULL);
/*
* Caller must have created the tuplestore already ... but not a snapshot.
*/
Assert(portal->holdContext != NULL);
Assert(portal->holdStore != NULL);
Assert(portal->holdSnapshot == NULL);
/*
* Before closing down the executor, we must copy the tupdesc into
* long-term memory, since it was created in executor memory.
*/
oldcxt = MemoryContextSwitchTo(portal->holdContext);
portal->tupDesc = CreateTupleDescCopy(portal->tupDesc);
MemoryContextSwitchTo(oldcxt);
/*
* Check for improper portal use, and mark portal active.
*/
MarkPortalActive(portal);
/*
* Set up global portal context pointers.
*/
saveActivePortal = ActivePortal;
saveResourceOwner = CurrentResourceOwner;
savePortalContext = PortalContext;
PG_TRY();
{
ActivePortal = portal;
if (portal->resowner)
CurrentResourceOwner = portal->resowner;
PortalContext = PortalGetHeapMemory(portal);
MemoryContextSwitchTo(PortalContext);
PushActiveSnapshot(queryDesc->snapshot);
/*
* Rewind the executor: we need to store the entire result set in the
* tuplestore, so that subsequent backward FETCHs can be processed.
*/
ExecutorRewind(queryDesc);
/*
* Change the destination to output to the tuplestore. Note we tell
* the tuplestore receiver to detoast all data passed through it; this
* makes it safe to not keep a snapshot associated with the data.
*/
queryDesc->dest = CreateDestReceiver(DestTuplestore);
SetTuplestoreDestReceiverParams(queryDesc->dest,
portal->holdStore,
portal->holdContext,
true);
/* Fetch the result set into the tuplestore */
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
(*queryDesc->dest->rDestroy) (queryDesc->dest);
queryDesc->dest = NULL;
/*
* Now shut down the inner executor.
*/
portal->queryDesc = NULL; /* prevent double shutdown */
ExecutorFinish(queryDesc);
ExecutorEnd(queryDesc);
FreeQueryDesc(queryDesc);
/*
* Set the position in the result set.
*/
MemoryContextSwitchTo(portal->holdContext);
if (portal->atEnd)
{
/*
* Just force the tuplestore forward to its end. The size of the
* skip request here is arbitrary.
*/
while (tuplestore_skiptuples(portal->holdStore, 1000000, true))
/* continue */ ;
}
else
{
tuplestore_rescan(portal->holdStore);
if (!tuplestore_skiptuples(portal->holdStore,
portal->portalPos,
true))
elog(ERROR, "unexpected end of tuple stream");
}
}
PG_CATCH();
{
/* Uncaught error while executing portal: mark it dead */
MarkPortalFailed(portal);
/* Restore global vars and propagate error */
ActivePortal = saveActivePortal;
CurrentResourceOwner = saveResourceOwner;
PortalContext = savePortalContext;
PG_RE_THROW();
}
PG_END_TRY();
MemoryContextSwitchTo(oldcxt);
/* Mark portal not active */
portal->status = PORTAL_READY;
ActivePortal = saveActivePortal;
CurrentResourceOwner = saveResourceOwner;
PortalContext = savePortalContext;
PopActiveSnapshot();
/*
* We can now release any subsidiary memory of the portal's heap context;
* we'll never use it again. The executor already dropped its context,
* but this will clean up anything that glommed onto the portal's heap via
* PortalContext.
*/
MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
}
/*
* PersistHoldablePortal
*
* Prepare the specified Portal for access outside of the current
* transaction. When this function returns, all future accesses to the
* portal must be done via the Tuplestore (not by invoking the
* executor).
*/
void
PersistHoldablePortal(Portal portal)
{
QueryDesc *queryDesc = PortalGetQueryDesc(portal);
MemoryContext savePortalContext;
MemoryContext saveQueryContext;
MemoryContext oldcxt;
/*
* If we're preserving a holdable portal, we had better be inside the
* transaction that originally created it.
*/
Assert(portal->createXact == GetCurrentTransactionId());
Assert(queryDesc != NULL);
Assert(portal->portalReady);
Assert(!portal->portalDone);
/*
* Caller must have created the tuplestore already.
*/
Assert(portal->holdContext != NULL);
Assert(portal->holdStore != NULL);
/*
* Before closing down the executor, we must copy the tupdesc into
* long-term memory, since it was created in executor memory.
*/
oldcxt = MemoryContextSwitchTo(portal->holdContext);
portal->tupDesc = CreateTupleDescCopy(portal->tupDesc);
MemoryContextSwitchTo(oldcxt);
/*
* Check for improper portal use, and mark portal active.
*/
if (portal->portalActive)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_IN_USE),
errmsg("portal \"%s\" already active", portal->name)));
portal->portalActive = true;
/*
* Set global portal context pointers.
*/
savePortalContext = PortalContext;
PortalContext = PortalGetHeapMemory(portal);
saveQueryContext = QueryContext;
QueryContext = portal->queryContext;
MemoryContextSwitchTo(PortalContext);
/*
* Rewind the executor: we need to store the entire result set in the
* tuplestore, so that subsequent backward FETCHs can be processed.
*/
ExecutorRewind(queryDesc);
/* Change the destination to output to the tuplestore */
queryDesc->dest = CreateDestReceiver(Tuplestore, portal);
/* Fetch the result set into the tuplestore */
ExecutorRun(queryDesc, ForwardScanDirection, 0L);
(*queryDesc->dest->rDestroy) (queryDesc->dest);
queryDesc->dest = NULL;
/*
* Now shut down the inner executor.
*/
portal->queryDesc = NULL; /* prevent double shutdown */
ExecutorEnd(queryDesc);
/* Mark portal not active */
portal->portalActive = false;
PortalContext = savePortalContext;
QueryContext = saveQueryContext;
/*
* Reset the position in the result set: ideally, this could be
* implemented by just skipping straight to the tuple # that we need
* to be at, but the tuplestore API doesn't support that. So we start
* at the beginning of the tuplestore and iterate through it until we
* reach where we need to be. FIXME someday?
*/
MemoryContextSwitchTo(portal->holdContext);
if (!portal->atEnd)
{
long store_pos;
if (portal->posOverflow) /* oops, cannot trust portalPos */
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not reposition held cursor")));
tuplestore_rescan(portal->holdStore);
for (store_pos = 0; store_pos < portal->portalPos; store_pos++)
{
HeapTuple tup;
bool should_free;
tup = tuplestore_gettuple(portal->holdStore, true,
&should_free);
if (tup == NULL)
elog(ERROR, "unexpected end of tuple stream");
if (should_free)
pfree(tup);
}
}
MemoryContextSwitchTo(oldcxt);
/*
* We can now release any subsidiary memory of the portal's heap
* context; we'll never use it again. The executor already dropped
* its context, but this will clean up anything that glommed onto the
* portal's heap via PortalContext.
*/
MemoryContextDeleteChildren(PortalGetHeapMemory(portal));
}
