Function ExecCreatePartitionPruneState

src/backend/executor/execPartition.c:1764–1973

* ExecCreatePartitionPruneState * Build the data structure required for calling * ExecFindInitialMatchingSubPlans and ExecFindMatchingSubPlans. * * 'planstate' is the parent plan node's execution state. * * 'partitionpruneinfo' is a PartitionPruneInfo as generated by * make_partition_pruneinfo. Here we build a PartitionPruneState containing a * PartitionPruningData for each partitioning

 * provided in each PartitionedRelPruneInfo.
 */
PartitionPruneState *
ExecCreatePartitionPruneState(PlanState *planstate,
							  PartitionPruneInfo *partitionpruneinfo)
{
	EState	   *estate = planstate->state;
	PartitionPruneState *prunestate;
	int			n_part_hierarchies;
	ListCell   *lc;
	int			i;

	/* For data reading, executor always omits detached partitions */
	if (estate->es_partition_directory == NULL)
		estate->es_partition_directory =
			CreatePartitionDirectory(estate->es_query_cxt, false);

	n_part_hierarchies = list_length(partitionpruneinfo->prune_infos);
	Assert(n_part_hierarchies > 0);

	/*
	 * Allocate the data structure
	 */
	prunestate = (PartitionPruneState *)
		palloc(offsetof(PartitionPruneState, partprunedata) +
			   sizeof(PartitionPruningData *) * n_part_hierarchies);

	prunestate->execparamids = NULL;
	/* other_subplans can change at runtime, so we need our own copy */
	prunestate->other_subplans = bms_copy(partitionpruneinfo->other_subplans);
	prunestate->do_initial_prune = false;	/* may be set below */
	prunestate->do_exec_prune = false;	/* may be set below */
	prunestate->num_partprunedata = n_part_hierarchies;

	/*
	 * Create a short-term memory context which we'll use when making calls to
	 * the partition pruning functions.  This avoids possible memory leaks,
	 * since the pruning functions call comparison functions that aren't under
	 * our control.
	 */
	prunestate->prune_context =
		AllocSetContextCreate(CurrentMemoryContext,
							  "Partition Prune",
							  ALLOCSET_DEFAULT_SIZES);

	i = 0;
	foreach(lc, partitionpruneinfo->prune_infos)
	{
		List	   *partrelpruneinfos = lfirst_node(List, lc);
		int			npartrelpruneinfos = list_length(partrelpruneinfos);
		PartitionPruningData *prunedata;
		ListCell   *lc2;
		int			j;

		prunedata = (PartitionPruningData *)
			palloc(offsetof(PartitionPruningData, partrelprunedata) +
				   npartrelpruneinfos * sizeof(PartitionedRelPruningData));
		prunestate->partprunedata[i] = prunedata;
		prunedata->num_partrelprunedata = npartrelpruneinfos;