/* ----------------------------------------------------------------
* ExecInitSubqueryScan
* ----------------------------------------------------------------
*/
SubqueryScanState *
ExecInitSubqueryScan(SubqueryScan *node, EState *estate)
{
SubqueryScanState *subquerystate;
RangeTblEntry *rte;
EState *sp_estate;
MemoryContext oldcontext;
/*
* SubqueryScan should not have any "normal" children.
*/
Assert(outerPlan(node) == NULL);
Assert(innerPlan(node) == NULL);
/*
* create state structure
*/
subquerystate = makeNode(SubqueryScanState);
subquerystate->ss.ps.plan = (Plan *) node;
subquerystate->ss.ps.state = estate;
/*
* Miscellaneous initialization
*
* create expression context for node
*/
ExecAssignExprContext(estate, &subquerystate->ss.ps);
/*
* initialize child expressions
*/
subquerystate->ss.ps.targetlist = (List *)
ExecInitExpr((Expr *) node->scan.plan.targetlist,
(PlanState *) subquerystate);
subquerystate->ss.ps.qual = (List *)
ExecInitExpr((Expr *) node->scan.plan.qual,
(PlanState *) subquerystate);
#define SUBQUERYSCAN_NSLOTS 2
/*
* tuple table initialization
*/
ExecInitResultTupleSlot(estate, &subquerystate->ss.ps);
ExecInitScanTupleSlot(estate, &subquerystate->ss);
/*
* initialize subquery
*
* This should agree with ExecInitSubPlan
*/
rte = rt_fetch(node->scan.scanrelid, estate->es_range_table);
Assert(rte->rtekind == RTE_SUBQUERY);
/*
* Do access checking on the rangetable entries in the subquery.
*/
ExecCheckRTPerms(rte->subquery->rtable);
/*
* The subquery needs its own EState because it has its own rangetable. It
* shares our Param ID space, however. XXX if rangetable access were done
* differently, the subquery could share our EState, which would eliminate
* some thrashing about in this module...
*/
sp_estate = CreateExecutorState();
subquerystate->sss_SubEState = sp_estate;
oldcontext = MemoryContextSwitchTo(sp_estate->es_query_cxt);
sp_estate->es_range_table = rte->subquery->rtable;
sp_estate->es_param_list_info = estate->es_param_list_info;
sp_estate->es_param_exec_vals = estate->es_param_exec_vals;
sp_estate->es_tupleTable =
ExecCreateTupleTable(ExecCountSlotsNode(node->subplan) + 10);
sp_estate->es_snapshot = estate->es_snapshot;
sp_estate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
sp_estate->es_instrument = estate->es_instrument;
/*
* Start up the subplan (this is a very cut-down form of InitPlan())
*/
subquerystate->subplan = ExecInitNode(node->subplan, sp_estate);
MemoryContextSwitchTo(oldcontext);
subquerystate->ss.ps.ps_TupFromTlist = false;
/*
* Initialize scan tuple type (needed by ExecAssignScanProjectionInfo)
*/
ExecAssignScanType(&subquerystate->ss,
ExecGetResultType(subquerystate->subplan),
false);
/*
* Initialize result tuple type and projection info.
*/
ExecAssignResultTypeFromTL(&subquerystate->ss.ps);
ExecAssignScanProjectionInfo(&subquerystate->ss);
return subquerystate;
}
/*
* IndexBuildHeapScan - scan the heap relation to find tuples to be indexed
*
* This is called back from an access-method-specific index build procedure
* after the AM has done whatever setup it needs. The parent heap relation
* is scanned to find tuples that should be entered into the index. Each
* such tuple is passed to the AM's callback routine, which does the right
* things to add it to the new index. After we return, the AM's index
* build procedure does whatever cleanup is needed; in particular, it should
* close the heap and index relations.
*
* The total count of heap tuples is returned. This is for updating pg_class
* statistics. (It's annoying not to be able to do that here, but we can't
* do it until after the relation is closed.) Note that the index AM itself
* must keep track of the number of index tuples; we don't do so here because
* the AM might reject some of the tuples for its own reasons, such as being
* unable to store NULLs.
*/
double
IndexBuildHeapScan(Relation heapRelation,
Relation indexRelation,
IndexInfo *indexInfo,
IndexBuildCallback callback,
void *callback_state)
{
HeapScanDesc scan;
HeapTuple heapTuple;
TupleDesc heapDescriptor;
Datum attdata[INDEX_MAX_KEYS];
char nulls[INDEX_MAX_KEYS];
double reltuples;
List *predicate;
TupleTable tupleTable;
TupleTableSlot *slot;
EState *estate;
ExprContext *econtext;
Snapshot snapshot;
TransactionId OldestXmin;
/*
* sanity checks
*/
Assert(OidIsValid(indexRelation->rd_rel->relam));
heapDescriptor = RelationGetDescr(heapRelation);
/*
* Need an EState for evaluation of index expressions and
* partial-index predicates.
*/
estate = CreateExecutorState();
econtext = GetPerTupleExprContext(estate);
/*
* If this is a predicate (partial) index, we will need to evaluate
* the predicate using ExecQual, which requires the current tuple to
* be in a slot of a TupleTable. Likewise if there are any
* expressions.
*/
if (indexInfo->ii_Predicate != NIL || indexInfo->ii_Expressions != NIL)
{
tupleTable = ExecCreateTupleTable(1);
slot = ExecAllocTableSlot(tupleTable);
ExecSetSlotDescriptor(slot, heapDescriptor, false);
/* Arrange for econtext's scan tuple to be the tuple under test */
econtext->ecxt_scantuple = slot;
/* Set up execution state for predicate. */
predicate = (List *)
ExecPrepareExpr((Expr *) indexInfo->ii_Predicate,
estate);
}
else
{
tupleTable = NULL;
slot = NULL;
predicate = NIL;
}
/*
* Ok, begin our scan of the base relation. We use SnapshotAny
* because we must retrieve all tuples and do our own time qual
* checks.
*/
if (IsBootstrapProcessingMode())
{
snapshot = SnapshotNow;
OldestXmin = InvalidTransactionId;
}
else
{
snapshot = SnapshotAny;
OldestXmin = GetOldestXmin(heapRelation->rd_rel->relisshared);
}
scan = heap_beginscan(heapRelation, /* relation */
snapshot, /* seeself */
0, /* number of keys */
(ScanKey) NULL); /* scan key */
reltuples = 0;
/*
* Scan all tuples in the base relation.
*/
while ((heapTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
bool tupleIsAlive;
CHECK_FOR_INTERRUPTS();
if (snapshot == SnapshotAny)
{
/* do our own time qual check */
bool indexIt;
uint16 sv_infomask;
/*
* HeapTupleSatisfiesVacuum may update tuple's hint status
* bits. We could possibly get away with not locking the
* buffer here, since caller should hold ShareLock on the
* relation, but let's be conservative about it.
*/
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
sv_infomask = heapTuple->t_data->t_infomask;
switch (HeapTupleSatisfiesVacuum(heapTuple->t_data, OldestXmin))
{
case HEAPTUPLE_DEAD:
indexIt = false;
tupleIsAlive = false;
break;
case HEAPTUPLE_LIVE:
indexIt = true;
tupleIsAlive = true;
break;
case HEAPTUPLE_RECENTLY_DEAD:
/*
* If tuple is recently deleted then we must index it
* anyway to keep VACUUM from complaining.
*/
indexIt = true;
tupleIsAlive = false;
break;
case HEAPTUPLE_INSERT_IN_PROGRESS:
/*
* Since caller should hold ShareLock or better, we
* should not see any tuples inserted by open
* transactions --- unless it's our own transaction.
* (Consider INSERT followed by CREATE INDEX within a
* transaction.) An exception occurs when reindexing
* a system catalog, because we often release lock on
* system catalogs before committing.
*/
if (!TransactionIdIsCurrentTransactionId(
HeapTupleHeaderGetXmin(heapTuple->t_data))
&& !IsSystemRelation(heapRelation))
elog(ERROR, "concurrent insert in progress");
indexIt = true;
tupleIsAlive = true;
break;
case HEAPTUPLE_DELETE_IN_PROGRESS:
/*
* Since caller should hold ShareLock or better, we
* should not see any tuples deleted by open
* transactions --- unless it's our own transaction.
* (Consider DELETE followed by CREATE INDEX within a
* transaction.) An exception occurs when reindexing
* a system catalog, because we often release lock on
* system catalogs before committing.
*/
if (!TransactionIdIsCurrentTransactionId(
HeapTupleHeaderGetXmax(heapTuple->t_data))
&& !IsSystemRelation(heapRelation))
elog(ERROR, "concurrent delete in progress");
indexIt = true;
tupleIsAlive = false;
break;
default:
elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
indexIt = tupleIsAlive = false; /* keep compiler quiet */
break;
}
/* check for hint-bit update by HeapTupleSatisfiesVacuum */
if (sv_infomask != heapTuple->t_data->t_infomask)
SetBufferCommitInfoNeedsSave(scan->rs_cbuf);
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
if (!indexIt)
continue;
}
else
{
/* heap_getnext did the time qual check */
tupleIsAlive = true;
}
reltuples += 1;
MemoryContextReset(econtext->ecxt_per_tuple_memory);
/* Set up for predicate or expression evaluation */
if (slot)
ExecStoreTuple(heapTuple, slot, InvalidBuffer, false);
/*
* In a partial index, discard tuples that don't satisfy the
* predicate. We can also discard recently-dead tuples, since
* VACUUM doesn't complain about tuple count mismatch for partial
* indexes.
*/
if (predicate != NIL)
{
if (!tupleIsAlive)
continue;
if (!ExecQual(predicate, econtext, false))
continue;
}
/*
* For the current heap tuple, extract all the attributes we use
* in this index, and note which are null. This also performs
* evaluation of any expressions needed.
*/
FormIndexDatum(indexInfo,
heapTuple,
heapDescriptor,
estate,
attdata,
nulls);
/*
* You'd think we should go ahead and build the index tuple here,
* but some index AMs want to do further processing on the data
* first. So pass the attdata and nulls arrays, instead.
*/
/* Call the AM's callback routine to process the tuple */
callback(indexRelation, heapTuple, attdata, nulls, tupleIsAlive,
callback_state);
}
heap_endscan(scan);
if (tupleTable)
ExecDropTupleTable(tupleTable, true);
FreeExecutorState(estate);
/* These may have been pointing to the now-gone estate */
indexInfo->ii_ExpressionsState = NIL;
indexInfo->ii_PredicateState = NIL;
return reltuples;
}
