/*
* setPidIndex
* Set the hash table of Oids to scan.
*/
static void
setPidIndex(DynamicIndexScanState *node)
{
Assert(node->pidxIndex == NULL);
IndexScanState *indexState = (IndexScanState *)node;
EState *estate = indexState->ss.ps.state;
DynamicIndexScan *plan = (DynamicIndexScan *)indexState->ss.ps.plan;
Assert(estate->dynamicTableScanInfo != NULL);
/*
* Ensure that the dynahash exists even if the partition selector
* didn't choose any partition for current scan node [MPP-24169].
*/
InsertPidIntoDynamicTableScanInfo(plan->scan.partIndex, InvalidOid, InvalidPartitionSelectorId);
Assert(NULL != estate->dynamicTableScanInfo->pidIndexes);
Assert(estate->dynamicTableScanInfo->numScans >= plan->scan.partIndex);
node->pidxIndex = estate->dynamicTableScanInfo->pidIndexes[plan->scan.partIndex - 1];
Assert(node->pidxIndex != NULL);
if (optimizer_partition_selection_log)
{
LogSelectedPartitionOids(node->pidxIndex);
}
}
/*
* DynamicScan_CreateIterator
* Creates an iterator state (i.e., DynamicPartitionIterator)
* and saves it to the estate's DynamicTableScanInfo.
*/
static void
DynamicScan_CreateIterator(ScanState *scanState, Scan *scan)
{
EState *estate = scanState->ps.state;
Assert(NULL != estate);
DynamicTableScanInfo *partitionInfo = estate->dynamicTableScanInfo;
/*
* Ensure that the dynahash exists even if the partition selector
* didn't choose any partition for current scan node [MPP-24169].
*/
InsertPidIntoDynamicTableScanInfo(scan->partIndex, InvalidOid, InvalidPartitionSelectorId);
Assert(NULL != partitionInfo && NULL != partitionInfo->pidIndexes);
Assert(partitionInfo->numScans >= scan->partIndex);
Assert(NULL == partitionInfo->iterators[scan->partIndex - 1]);
DynamicPartitionIterator *iterator = palloc(sizeof(DynamicPartitionIterator));
iterator->curRelOid = InvalidOid;
iterator->partitionMemoryContext = AllocSetContextCreate(CurrentMemoryContext,
"DynamicTableScanPerPartition",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
iterator->partitionOids = partitionInfo->pidIndexes[scan->partIndex - 1];
Assert(iterator->partitionOids != NULL);
iterator->shouldCallHashSeqTerm = true;
HASH_SEQ_STATUS *partitionIterator = palloc(sizeof(HASH_SEQ_STATUS));
hash_seq_init(partitionIterator, iterator->partitionOids);
iterator->partitionIterator = partitionIterator;
partitionInfo->iterators[scan->partIndex - 1] = iterator;
}
/*
* gp_partition_propagation
* Insert a partition oid into its pid-index.
*/
Datum
gp_partition_propagation(PG_FUNCTION_ARGS)
{
int32 index = PG_GETARG_INT32(0);
Oid partOid = PG_GETARG_OID(1);
InsertPidIntoDynamicTableScanInfo(index, partOid, InvalidPartitionSelectorId);
PG_RETURN_VOID();
}
/* ----------------------------------------------------------------
* ExecPartitionSelector(node)
*
* Compute and propagate partition table Oids that will be
* used by Dynamic table scan. There are two ways of
* executing PartitionSelector.
*
* 1. Constant partition elimination
* Plan structure:
* Sequence
* |--PartitionSelector
* |--DynamicTableScan
* In this case, PartitionSelector evaluates constant partition
* constraints to compute and propagate partition table Oids.
* It only need to be called once.
*
* 2. Join partition elimination
* Plan structure:
* ...:
* |--DynamicTableScan
* |--...
* |--PartitionSelector
* |--...
* In this case, PartitionSelector is in the same slice as
* DynamicTableScan, DynamicIndexScan or DynamicBitmapHeapScan.
* It is executed for each tuple coming from its child node.
* It evaluates partition constraints with the input tuple and
* propagate matched partition table Oids.
*
*
* Instead of a Dynamic Table Scan, there can be other nodes that use
* a PartSelected qual to filter rows, based on which partitions are
* selected. Currently, ORCA uses Dynamic Table Scans, while plans
* produced by the non-ORCA planner use gating Result nodes with
* PartSelected quals, to exclude unwanted partitions.
*
* ----------------------------------------------------------------
*/
TupleTableSlot *
ExecPartitionSelector(PartitionSelectorState *node)
{
PartitionSelector *ps = (PartitionSelector *) node->ps.plan;
EState *estate = node->ps.state;
ExprContext *econtext = node->ps.ps_ExprContext;
TupleTableSlot *inputSlot = NULL;
TupleTableSlot *candidateOutputSlot = NULL;
if (ps->staticSelection)
{
/* propagate the part oids obtained via static partition selection */
partition_propagation(estate, ps->staticPartOids, ps->staticScanIds, ps->selectorId);
return NULL;
}
/* Retrieve PartitionNode and access method from root table.
* We cannot do it during node initialization as
* DynamicTableScanInfo is not properly initialized yet.
*/
if (NULL == node->rootPartitionNode)
{
Assert(NULL != estate->dynamicTableScanInfo);
getPartitionNodeAndAccessMethod
(
ps->relid,
estate->dynamicTableScanInfo->partsMetadata,
estate->es_query_cxt,
&node->rootPartitionNode,
&node->accessMethods
);
}
if (NULL != outerPlanState(node))
{
/* Join partition elimination */
/* get tuple from outer children */
PlanState *outerPlan = outerPlanState(node);
Assert(outerPlan);
inputSlot = ExecProcNode(outerPlan);
if (TupIsNull(inputSlot))
{
/* no more tuples from outerPlan */
/*
* Make sure we have an entry for this scan id in
* dynamicTableScanInfo. Normally, this would've been done the
* first time a partition is selected, but we must ensure that
* there is an entry even if no partitions were selected.
* (The traditional Postgres planner uses this method.)
*/
if (ps->partTabTargetlist)
InsertPidIntoDynamicTableScanInfo(estate, ps->scanId, InvalidOid, ps->selectorId);
else
LogPartitionSelection(estate, ps->selectorId);
return NULL;
}
}
/* partition elimination with the given input tuple */
ResetExprContext(econtext);
node->ps.ps_OuterTupleSlot = inputSlot;
econtext->ecxt_outertuple = inputSlot;
econtext->ecxt_scantuple = inputSlot;
if (NULL != inputSlot)
{
candidateOutputSlot = ExecProject(node->ps.ps_ProjInfo, NULL);
}
/*
* If we have a partitioning projection, project the input tuple
* into a tuple that looks like tuples from the partitioned table, and use
* selectPartitionMulti() to select the partitions. (The traditional
* Postgres planner uses this method.)
*/
if (ps->partTabTargetlist)
{
TupleTableSlot *slot;
List *oids;
ListCell *lc;
slot = ExecProject(node->partTabProj, NULL);
slot_getallattrs(slot);
oids = selectPartitionMulti(node->rootPartitionNode,
slot_get_values(slot),
slot_get_isnull(slot),
slot->tts_tupleDescriptor,
node->accessMethods);
foreach (lc, oids)
{
InsertPidIntoDynamicTableScanInfo(estate, ps->scanId, lfirst_oid(lc), ps->selectorId);
}