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Commit99e922a

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Repair planner failure when there are multiple IN clauses, each with
a join in its subselect. In this situation we *must* build a bushyplan because there are no valid left-sided or right-sided join trees.Accordingly, hoary sanity check needs an update. Per report fromAlessandro Depase.
1 parent9dddd24 commit99e922a

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2 files changed

+22
-3
lines changed

2 files changed

+22
-3
lines changed

‎src/backend/optimizer/path/allpaths.c‎

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.109 2003/11/29 19:51:50 pgsql Exp $
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* $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.110 2003/12/17 17:07:48 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
@@ -545,6 +545,8 @@ make_one_rel_by_joins(Query *root, int levels_needed, List *initial_rels)
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/*
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* We should have a single rel at the final level.
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*/
548+
if (joinitems[levels_needed]==NIL)
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elog(ERROR,"failed to build any %d-way joins",levels_needed);
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Assert(length(joinitems[levels_needed])==1);
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rel= (RelOptInfo*)lfirst(joinitems[levels_needed]);

‎src/backend/optimizer/path/joinrels.c‎

Lines changed: 19 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/optimizer/path/joinrels.c,v 1.64 2003/11/29 19:51:50 pgsql Exp $
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* $PostgreSQL: pgsql/src/backend/optimizer/path/joinrels.c,v 1.65 2003/12/17 17:07:48 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
@@ -226,7 +226,24 @@ make_rels_by_joins(Query *root, int level, List **joinrels)
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}
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}
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if (result_rels==NIL)
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/*----------
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* When IN clauses are involved, there may be no legal way to make
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* an N-way join for some values of N. For example consider
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*
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* SELECT ... FROM t1 WHERE
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* x IN (SELECT ... FROM t2,t3 WHERE ...) AND
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* y IN (SELECT ... FROM t4,t5 WHERE ...)
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*
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* We will flatten this query to a 5-way join problem, but there are
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* no 4-way joins that make_join_rel() will consider legal. We have
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* to accept failure at level 4 and go on to discover a workable
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* bushy plan at level 5.
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*
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* However, if there are no IN clauses then make_join_rel() should
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* never fail, and so the following sanity check is useful.
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*----------
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*/
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if (result_rels==NIL&&root->in_info_list==NIL)
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elog(ERROR,"failed to build any %d-way joins",level);
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}
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