Centralize executor-related partitioning code.

Some code is moved from partition.c, which has grown very quickly lately;
splitting the executor parts out might help to keep it from getting
totally out of control.  Other code is moved from execMain.c.  All is
moved to a new file execPartition.c.  get_partition_for_tuple now has
a new interface that more clearly separates executor concerns from
generic concerns.

Amit Langote.  A slight comment tweak by me.

Discussion: http://postgr.es/m/1f0985f8-3b61-8bc4-4350-baa6d804cb6d@lab.ntt.co.jp

Author: robertmhaas

src/backend/catalog/partition.c

@@ -27,6 +27,7 @@
 #include "commands/copy.h"
 #include "commands/defrem.h"
 #include "commands/trigger.h"
+#include "executor/execPartition.h"
 #include "executor/executor.h"
 #include "libpq/libpq.h"
 #include "libpq/pqformat.h"

src/backend/commands/copy.c

@@ -14,7 +14,7 @@ include $(top_builddir)/src/Makefile.global
 
 OBJS = execAmi.o execCurrent.o execExpr.o execExprInterp.o \
        execGrouping.o execIndexing.o execJunk.o \
-       execMain.o execParallel.o execProcnode.o \
+       execMain.o execParallel.o execPartition.o execProcnode.o \
        execReplication.o execScan.o execSRF.o execTuples.o \
        execUtils.o functions.o instrument.o nodeAppend.o nodeAgg.o \
        nodeBitmapAnd.o nodeBitmapOr.o \

src/backend/executor/Makefile

@@ -43,7 +43,6 @@
 #include "access/xact.h"
 #include "catalog/namespace.h"
 #include "catalog/partition.h"
-#include "catalog/pg_inherits_fn.h"
 #include "catalog/pg_publication.h"
 #include "commands/matview.h"
 #include "commands/trigger.h"
@@ -98,14 +97,8 @@ static char *ExecBuildSlotValueDescription(Oid reloid,
 							  TupleDesc tupdesc,
 							  Bitmapset *modifiedCols,
 							  int maxfieldlen);
-static char *ExecBuildSlotPartitionKeyDescription(Relation rel,
-									 Datum *values,
-									 bool *isnull,
-									 int maxfieldlen);
 static void EvalPlanQualStart(EPQState *epqstate, EState *parentestate,
 				  Plan *planTree);
-static void ExecPartitionCheck(ResultRelInfo *resultRelInfo,
-				   TupleTableSlot *slot, EState *estate);
 
 /*
  * Note that GetUpdatedColumns() also exists in commands/trigger.c.  There does
@@ -1854,8 +1847,10 @@ ExecRelCheck(ResultRelInfo *resultRelInfo,
 
 /*
  * ExecPartitionCheck --- check that tuple meets the partition constraint.
+ *
+ * Exported in executor.h for outside use.
  */
-static void
+void
 ExecPartitionCheck(ResultRelInfo *resultRelInfo, TupleTableSlot *slot,
 				   EState *estate)
 {
@@ -3245,258 +3240,3 @@ EvalPlanQualEnd(EPQState *epqstate)
 	epqstate->planstate = NULL;
 	epqstate->origslot = NULL;
 }
-
-/*
- * ExecSetupPartitionTupleRouting - set up information needed during
- * tuple routing for partitioned tables
- *
- * Output arguments:
- * 'pd' receives an array of PartitionDispatch objects with one entry for
- *		every partitioned table in the partition tree
- * 'partitions' receives an array of ResultRelInfo* objects with one entry for
- *		every leaf partition in the partition tree
- * 'tup_conv_maps' receives an array of TupleConversionMap objects with one
- *		entry for every leaf partition (required to convert input tuple based
- *		on the root table's rowtype to a leaf partition's rowtype after tuple
- *		routing is done)
- * 'partition_tuple_slot' receives a standalone TupleTableSlot to be used
- *		to manipulate any given leaf partition's rowtype after that partition
- *		is chosen by tuple-routing.
- * 'num_parted' receives the number of partitioned tables in the partition
- *		tree (= the number of entries in the 'pd' output array)
- * 'num_partitions' receives the number of leaf partitions in the partition
- *		tree (= the number of entries in the 'partitions' and 'tup_conv_maps'
- *		output arrays
- *
- * Note that all the relations in the partition tree are locked using the
- * RowExclusiveLock mode upon return from this function.
- */
-void
-ExecSetupPartitionTupleRouting(Relation rel,
-							   Index resultRTindex,
-							   EState *estate,
-							   PartitionDispatch **pd,
-							   ResultRelInfo ***partitions,
-							   TupleConversionMap ***tup_conv_maps,
-							   TupleTableSlot **partition_tuple_slot,
-							   int *num_parted, int *num_partitions)
-{
-	TupleDesc	tupDesc = RelationGetDescr(rel);
-	List	   *leaf_parts;
-	ListCell   *cell;
-	int			i;
-	ResultRelInfo *leaf_part_rri;
-
-	/*
-	 * Get the information about the partition tree after locking all the
-	 * partitions.
-	 */
-	(void) find_all_inheritors(RelationGetRelid(rel), RowExclusiveLock, NULL);
-	*pd = RelationGetPartitionDispatchInfo(rel, num_parted, &leaf_parts);
-	*num_partitions = list_length(leaf_parts);
-	*partitions = (ResultRelInfo **) palloc(*num_partitions *
-											sizeof(ResultRelInfo *));
-	*tup_conv_maps = (TupleConversionMap **) palloc0(*num_partitions *
-													 sizeof(TupleConversionMap *));
-
-	/*
-	 * Initialize an empty slot that will be used to manipulate tuples of any
-	 * given partition's rowtype.  It is attached to the caller-specified node
-	 * (such as ModifyTableState) and released when the node finishes
-	 * processing.
-	 */
-	*partition_tuple_slot = MakeTupleTableSlot();
-
-	leaf_part_rri = (ResultRelInfo *) palloc0(*num_partitions *
-											  sizeof(ResultRelInfo));
-	i = 0;
-	foreach(cell, leaf_parts)
-	{
-		Relation	partrel;
-		TupleDesc	part_tupdesc;
-
-		/*
-		 * We locked all the partitions above including the leaf partitions.
-		 * Note that each of the relations in *partitions are eventually
-		 * closed by the caller.
-		 */
-		partrel = heap_open(lfirst_oid(cell), NoLock);
-		part_tupdesc = RelationGetDescr(partrel);
-
-		/*
-		 * Save a tuple conversion map to convert a tuple routed to this
-		 * partition from the parent's type to the partition's.
-		 */
-		(*tup_conv_maps)[i] = convert_tuples_by_name(tupDesc, part_tupdesc,
-													 gettext_noop("could not convert row type"));
-
-		InitResultRelInfo(leaf_part_rri,
-						  partrel,
-						  resultRTindex,
-						  rel,
-						  estate->es_instrument);
-
-		/*
-		 * Verify result relation is a valid target for INSERT.
-		 */
-		CheckValidResultRel(leaf_part_rri, CMD_INSERT);
-
-		/*
-		 * Open partition indices (remember we do not support ON CONFLICT in
-		 * case of partitioned tables, so we do not need support information
-		 * for speculative insertion)
-		 */
-		if (leaf_part_rri->ri_RelationDesc->rd_rel->relhasindex &&
-			leaf_part_rri->ri_IndexRelationDescs == NULL)
-			ExecOpenIndices(leaf_part_rri, false);
-
-		estate->es_leaf_result_relations =
-			lappend(estate->es_leaf_result_relations, leaf_part_rri);
-
-		(*partitions)[i] = leaf_part_rri++;
-		i++;
-	}
-}
-
-/*
- * ExecFindPartition -- Find a leaf partition in the partition tree rooted
- * at parent, for the heap tuple contained in *slot
- *
- * estate must be non-NULL; we'll need it to compute any expressions in the
- * partition key(s)
- *
- * If no leaf partition is found, this routine errors out with the appropriate
- * error message, else it returns the leaf partition sequence number returned
- * by get_partition_for_tuple() unchanged.
- */
-int
-ExecFindPartition(ResultRelInfo *resultRelInfo, PartitionDispatch *pd,
-				  TupleTableSlot *slot, EState *estate)
-{
-	int			result;
-	PartitionDispatchData *failed_at;
-	TupleTableSlot *failed_slot;
-
-	/*
-	 * First check the root table's partition constraint, if any.  No point in
-	 * routing the tuple if it doesn't belong in the root table itself.
-	 */
-	if (resultRelInfo->ri_PartitionCheck)
-		ExecPartitionCheck(resultRelInfo, slot, estate);
-
-	result = get_partition_for_tuple(pd, slot, estate,
-									 &failed_at, &failed_slot);
-	if (result < 0)
-	{
-		Relation	failed_rel;
-		Datum		key_values[PARTITION_MAX_KEYS];
-		bool		key_isnull[PARTITION_MAX_KEYS];
-		char	   *val_desc;
-		ExprContext *ecxt = GetPerTupleExprContext(estate);
-
-		failed_rel = failed_at->reldesc;
-		ecxt->ecxt_scantuple = failed_slot;
-		FormPartitionKeyDatum(failed_at, failed_slot, estate,
-							  key_values, key_isnull);
-		val_desc = ExecBuildSlotPartitionKeyDescription(failed_rel,
-														key_values,
-														key_isnull,
-														64);
-		Assert(OidIsValid(RelationGetRelid(failed_rel)));
-		ereport(ERROR,
-				(errcode(ERRCODE_CHECK_VIOLATION),
-				 errmsg("no partition of relation \"%s\" found for row",
-						RelationGetRelationName(failed_rel)),
-				 val_desc ? errdetail("Partition key of the failing row contains %s.", val_desc) : 0));
-	}
-
-	return result;
-}
-
-/*
- * BuildSlotPartitionKeyDescription
- *
- * This works very much like BuildIndexValueDescription() and is currently
- * used for building error messages when ExecFindPartition() fails to find
- * partition for a row.
- */
-static char *
-ExecBuildSlotPartitionKeyDescription(Relation rel,
-									 Datum *values,
-									 bool *isnull,
-									 int maxfieldlen)
-{
-	StringInfoData buf;
-	PartitionKey key = RelationGetPartitionKey(rel);
-	int			partnatts = get_partition_natts(key);
-	int			i;
-	Oid			relid = RelationGetRelid(rel);
-	AclResult	aclresult;
-
-	if (check_enable_rls(relid, InvalidOid, true) == RLS_ENABLED)
-		return NULL;
-
-	/* If the user has table-level access, just go build the description. */
-	aclresult = pg_class_aclcheck(relid, GetUserId(), ACL_SELECT);
-	if (aclresult != ACLCHECK_OK)
-	{
-		/*
-		 * Step through the columns of the partition key and make sure the
-		 * user has SELECT rights on all of them.
-		 */
-		for (i = 0; i < partnatts; i++)
-		{
-			AttrNumber	attnum = get_partition_col_attnum(key, i);
-
-			/*
-			 * If this partition key column is an expression, we return no
-			 * detail rather than try to figure out what column(s) the
-			 * expression includes and if the user has SELECT rights on them.
-			 */
-			if (attnum == InvalidAttrNumber ||
-				pg_attribute_aclcheck(relid, attnum, GetUserId(),
-									  ACL_SELECT) != ACLCHECK_OK)
-				return NULL;
-		}
-	}
-
-	initStringInfo(&buf);
-	appendStringInfo(&buf, "(%s) = (",
-					 pg_get_partkeydef_columns(relid, true));
-
-	for (i = 0; i < partnatts; i++)
-	{
-		char	   *val;
-		int			vallen;
-
-		if (isnull[i])
-			val = "null";
-		else
-		{
-			Oid			foutoid;
-			bool		typisvarlena;
-
-			getTypeOutputInfo(get_partition_col_typid(key, i),
-							  &foutoid, &typisvarlena);
-			val = OidOutputFunctionCall(foutoid, values[i]);
-		}
-
-		if (i > 0)
-			appendStringInfoString(&buf, ", ");
-
-		/* truncate if needed */
-		vallen = strlen(val);
-		if (vallen <= maxfieldlen)
-			appendStringInfoString(&buf, val);
-		else
-		{
-			vallen = pg_mbcliplen(val, vallen, maxfieldlen);
-			appendBinaryStringInfo(&buf, val, vallen);
-			appendStringInfoString(&buf, "...");
-		}
-	}
-
-	appendStringInfoChar(&buf, ')');
-
-	return buf.data;
-}