Check outer entry in left join.

pull/7973/merge^2
eaydingol 2025-04-29 12:00:49 +03:00
parent 31b319d84f
commit 5c05af952f
7 changed files with 161 additions and 112 deletions

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@ -317,8 +317,8 @@ BuildSelectStatementViaStdPlanner(Query *combineQuery, List *remoteScanTargetLis
/*
* FindCitusExtradataContainerRTE is a helper function that finds the
* citus_extradata_container in range table entry.
* ExtractCitusExtradataContainerRTE is a helper function that stores rangeTblEntry
* to result if it has citus extra data container.
*
* The function returns true if it finds the RTE, and false otherwise.
*/

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@ -34,11 +34,13 @@
#include "distributed/combine_query_planner.h"
#include "distributed/deparse_shard_query.h"
#include "distributed/insert_select_planner.h"
#include "distributed/query_utils.h"
#include "distributed/listutils.h"
#include "distributed/local_executor.h"
#include "distributed/metadata_cache.h"
#include "distributed/multi_physical_planner.h"
#include "distributed/multi_router_planner.h"
#include "distributed/recursive_planning.h"
#include "distributed/shard_utils.h"
#include "distributed/utils/citus_stat_tenants.h"
#include "distributed/version_compat.h"
@ -205,58 +207,6 @@ UpdateTaskQueryString(Query *query, Task *task)
}
/*
* ExtractRangeTableIds walks over the given node, and finds all range
* table entries.
*/
bool
ExtractRangeTableIds(Node *node, ExtractRangeTableIdsContext *context)
{
List **rangeTableList = context->result;
List *rtable = context->rtable;
if (node == NULL)
{
return false;
}
if (IsA(node, RangeTblRef))
{
int rangeTableIndex = ((RangeTblRef *) node)->rtindex;
RangeTblEntry *rte = rt_fetch(rangeTableIndex, rtable);
if (rte->rtekind == RTE_SUBQUERY)
{
Query *subquery = rte->subquery;
context->rtable = subquery->rtable;
ExtractRangeTableIds((Node *) subquery, context);
context->rtable = rtable; /* restore original rtable */
}
else if (rte->rtekind == RTE_RELATION || rte->rtekind == RTE_FUNCTION)
{
(*rangeTableList) = lappend(*rangeTableList, rte);
ereport(DEBUG4, (errmsg("ExtractRangeTableIds: found range table id %d", rte->relid)));
}
else
{
ereport(DEBUG4, (errmsg("Unsupported RTE kind in ExtractRangeTableIds %d", rte->rtekind)));
}
return false;
}
else if (IsA(node, Query))
{
context->rtable = ((Query *) node)->rtable;
query_tree_walker((Query *) node, ExtractRangeTableIds, context, 0);
context->rtable = rtable; /* restore original rtable */
return false;
}
else
{
return expression_tree_walker(node, ExtractRangeTableIds, context);
}
}
/*
* Iterates through the FROM clause of the query and checks if there is a join
* clause with a reference and distributed table.
@ -291,54 +241,16 @@ GetRepresentativeTablesFromJoinClause(List *fromlist, List *rtable, RangeTblEntr
int outerRtIndex = ((RangeTblRef *)joinExpr->larg)->rtindex;
RangeTblEntry *outerRte = rt_fetch(outerRtIndex, rtable);
/* the outer table is a reference table */
if (outerRte->rtekind == RTE_FUNCTION)
if(!IsPushdownSafeForRTEInLeftJoin(outerRte))
{
RangeTblEntry *newRte = NULL;
if (!ExtractCitusExtradataContainerRTE(outerRte, &newRte))
{
/* RTE does not contain citus_extradata_container */
return -1;
}
}
else if (outerRte->rtekind == RTE_RELATION)
{
/* OK */
ereport(DEBUG5, (errmsg("\t\t outerRte: is RTE_RELATION")));
}
else
{
ereport(DEBUG5, (errmsg("\t\t not supported RTE kind %d", outerRte->rtekind)));
ereport(DEBUG5, (errmsg("GetRepresentativeTablesFromJoinClause: RTE is not pushdown safe")));
return -1;
}
ereport(DEBUG5, (errmsg("\t OK outerRte: %s", outerRte->eref->aliasname)));
int innerRelid = InvalidOid;
ExtractRangeTableIdsContext context;
List *innerRteList = NIL;
context.result = &innerRteList;
context.rtable = rtable;
/* TODO: what if we call this also for LHS? */
ExtractRangeTableIds((Node *)joinExpr->rarg, &context);
List *citusRelids = NIL;
RangeTblEntry *rte = NIL;
ListCell *lc;
foreach(lc, innerRteList)
if (!CheckIfAllCitusRTEsAreColocated((Node *)joinExpr->rarg, rtable, innerRte))
{
rte = (RangeTblEntry *) lfirst(lc);
if (IsCitusTable(rte->relid))
{
citusRelids = lappend_int(citusRelids, rte->relid);
*innerRte = rte; // set the value of innerRte
}
}
if (!AllDistributedRelationsInListColocated(citusRelids))
{
ereport(DEBUG5, (errmsg("The distributed tables are not colocated")));
return -1;
}

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@ -73,6 +73,7 @@
#include "distributed/citus_nodes.h"
#include "distributed/citus_ruleutils.h"
#include "distributed/combine_query_planner.h"
#include "distributed/commands/multi_copy.h"
#include "distributed/distributed_planner.h"
#include "distributed/errormessage.h"
@ -709,17 +710,27 @@ RecursivelyPlanRecurringTupleOuterJoinWalker(Node *node, Query *query,
{
/* <recurring> left join <distributed> */
/* TODO: For now, just disable the recursive planning here.
* However, we should add further checks, i.e., left node is a subquery
* that can not be pushed down with additional constrains.
/* Recursively plan the right side of the left left join when the following
* conditions are met:
* 1. The left side is recurring
* 2. The right side is not recurring
* 3. The left side is not a RangeTblRef (i.e., it is not a reference/local table)
* 4. The tables in the rigt side are not colocated.
* 5. The left side does not have the distribution column
*/
if (leftNodeRecurs && !rightNodeRecurs && false)
if (leftNodeRecurs && !rightNodeRecurs)
{
ereport(DEBUG1, (errmsg("recursively planning right side of "
"the left join since the outer side "
"is a recurring rel")));
RecursivelyPlanDistributedJoinNode(rightNode, query,
recursivePlanningContext);
int outerRtIndex = ((RangeTblRef *) leftNode)->rtindex;
RangeTblEntry *rte = rt_fetch(outerRtIndex, query->rtable);
if(!IsPushdownSafeForRTEInLeftJoin(rte))
{
ereport(DEBUG1, (errmsg("recursively planning right side of "
"the left join since the outer side "
"is a recurring rel that is not an RTE")));
RecursivelyPlanDistributedJoinNode(rightNode, query,
recursivePlanningContext);
}
}
/*
@ -2588,3 +2599,35 @@ GeneratingSubplans(void)
{
return recursivePlanningDepth > 0;
}
/*
* IsPushdownSafeForRTEInLeftJoin returns true if the given range table entry
* is safe for pushdown. Currently, we only allow RTE_RELATION and RTE_FUNCTION.
*/
bool IsPushdownSafeForRTEInLeftJoin(RangeTblEntry *rte)
{
if (rte->rtekind == RTE_RELATION)
{
return true;
}
/* check if it is a citus table, e.g., ref table */
else if (rte->rtekind == RTE_FUNCTION)
{
RangeTblEntry *newRte = NULL;
if(!ExtractCitusExtradataContainerRTE(rte, &newRte))
{
ereport(DEBUG5, (errmsg("RTE type %d is not safe for pushdown, function but it does not contain citus extradata",
rte->rtekind)));
return false;
}
return true;
}
else
{
ereport(DEBUG5, (errmsg("RTE type %d is not safe for pushdown",
rte->rtekind)));
return false;
}
}

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@ -15,9 +15,11 @@
#include "catalog/pg_class.h"
#include "nodes/nodeFuncs.h"
#include "nodes/primnodes.h"
#include "parser/parsetree.h"
#include "distributed/listutils.h"
#include "distributed/query_utils.h"
#include "distributed/relation_restriction_equivalence.h"
#include "distributed/version_compat.h"
@ -178,3 +180,93 @@ ExtractRangeTableIndexWalker(Node *node, List **rangeTableIndexList)
return walkerResult;
}
/*
* ExtractRangeTableIds walks over the given node, and finds all range
* table entries.
*/
bool
ExtractRangeTableIds(Node *node, ExtractRangeTableIdsContext *context)
{
List **rangeTableList = context->idList;
List *rtable = context->rtable;
if (node == NULL)
{
return false;
}
if (IsA(node, RangeTblRef))
{
int rangeTableIndex = ((RangeTblRef *) node)->rtindex;
RangeTblEntry *rte = rt_fetch(rangeTableIndex, rtable);
if (rte->rtekind == RTE_SUBQUERY)
{
Query *subquery = rte->subquery;
context->rtable = subquery->rtable;
ExtractRangeTableIds((Node *) subquery, context);
context->rtable = rtable; /* restore original rtable */
}
else if (rte->rtekind == RTE_RELATION || rte->rtekind == RTE_FUNCTION)
{
(*rangeTableList) = lappend(*rangeTableList, rte);
ereport(DEBUG4, (errmsg("ExtractRangeTableIds: found range table id %d", rte->relid)));
}
else
{
ereport(DEBUG4, (errmsg("Unsupported RTE kind in ExtractRangeTableIds %d", rte->rtekind)));
}
return false;
}
else if (IsA(node, Query))
{
context->rtable = ((Query *) node)->rtable;
query_tree_walker((Query *) node, ExtractRangeTableIds, context, 0);
context->rtable = rtable; /* restore original rtable */
return false;
}
else
{
return expression_tree_walker(node, ExtractRangeTableIds, context);
}
}
/*
* CheckIfAllCitusRTEsAreColocated checks if all distributed tables in the
* given node are colocated. If they are, it sets the value of rte to a
* representative table.
*/
bool CheckIfAllCitusRTEsAreColocated(Node *node, List *rtable, RangeTblEntry **rte)
{
ExtractRangeTableIdsContext context;
List *idList = NIL;
context.idList = &idList;
context.rtable = rtable;
ExtractRangeTableIds(node, &context);
RangeTblEntry *rteTmp;
List *citusRelids = NIL;
ListCell *lc = NULL;
foreach(lc, idList)
{
rteTmp = (RangeTblEntry *) lfirst(lc);
if (IsCitusTable(rteTmp->relid))
{
citusRelids = lappend_int(citusRelids, rteTmp->relid);
*rte = rteTmp; // set the value of rte, a representative table
}
}
if (!AllDistributedRelationsInListColocated(citusRelids))
{
ereport(DEBUG5, (errmsg("The distributed tables are not colocated")));
return false;
}
return true;
}

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@ -23,15 +23,8 @@
#include "distributed/query_utils.h"
/* Struct to pass rtable list and the result list to walker */
typedef struct ExtractRangeTableIdsContext
{
List **result;
List *rtable;
} ExtractRangeTableIdsContext;
int GetRepresentativeTablesFromJoinClause(List *fromlist, List *rtable, RangeTblEntry **innerRte);
bool ExtractRangeTableIds(Node *node, ExtractRangeTableIdsContext *context);
extern void RebuildQueryStrings(Job *workerJob);
extern bool UpdateRelationToShardNames(Node *node, List *relationShardList);
extern bool UpdateWhereClauseForOuterJoin(Node *node, List *relationShardList);

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@ -30,6 +30,13 @@ typedef struct ExtractRangeTableWalkerContext
ExtractRangeTableMode walkerMode;
} ExtractRangeTableWalkerContext;
/* Struct to pass rtable list and the result list to walker */
typedef struct ExtractRangeTableIdsContext
{
List **idList;
List *rtable;
} ExtractRangeTableIdsContext;
/* Function declarations for query-walker utility functions */
extern bool ExtractRangeTableList(Node *node, ExtractRangeTableWalkerContext *context);
@ -38,5 +45,6 @@ extern bool ExtractRangeTableRelationWalker(Node *node, List **rangeTableList);
extern bool ExtractRangeTableEntryWalker(Node *node, List **rangeTableList);
extern bool ExtractRangeTableIndexWalker(Node *node, List **rangeTableIndexList);
extern bool ExtractRangeTableIds(Node *node, ExtractRangeTableIdsContext *context);
extern bool CheckIfAllCitusRTEsAreColocated(Node *node, List *rtable, RangeTblEntry **rte);
#endif /* QUERY_UTILS_H */

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@ -51,6 +51,7 @@ extern bool IsRecursivelyPlannableRelation(RangeTblEntry *rangeTableEntry);
extern bool IsRelationLocalTableOrMatView(Oid relationId);
extern bool ContainsReferencesToOuterQuery(Query *query);
extern void UpdateVarNosInNode(Node *node, Index newVarNo);
extern bool IsPushdownSafeForRTEInLeftJoin(RangeTblEntry *rte);
#endif /* RECURSIVE_PLANNING_H */