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pgsql: Strip removed-relation references from PlaceHolderVars at join r 5+ messages / 1 participants [nested] [flat]
* pgsql: Strip removed-relation references from PlaceHolderVars at join r @ 2026-06-22 01:44 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 5+ messages in thread From: Richard Guo @ 2026-06-22 01:44 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Strip removed-relation references from PlaceHolderVars at join removal When left-join removal deletes a relation, remove_rel_from_query() updates the relid sets attached to RestrictInfos and EquivalenceMembers, and the canonical PlaceHolderVar held in each PlaceHolderInfo, but it does not rewrite the PlaceHolderVars embedded in clause and EquivalenceClass member expressions. That has been fine, because later processing consults those relid sets rather than the embedded PlaceHolderVars. However, such an expression may afterwards be translated for an appendrel child and have its relids recomputed from scratch by pull_varnos(). If the embedded PlaceHolderVar's phrels still mentions the removed relation, pull_varnos() folds it back in, so the rebuilt clause's relids reference a no-longer-existent relation. That yields a parameterized path keyed on the removed relation, tripping the Assert on root->outer_join_rels in get_eclass_indexes_for_relids(). Fix by stripping the removed relids from the PlaceHolderVars in surviving rels' baserestrictinfo and in EquivalenceClass member expressions, keeping them consistent with the canonical PlaceHolderVars. This is only reachable on v18 and later, where match_index_to_operand() began ignoring PlaceHolderVars; before that, the wrapping PlaceHolderVar prevented the index match that exposes the stale relids. Reported-by: Alexander Kuzmenkov <akuzmenkov@tigerdata.com> Author: Richard Guo <guofenglinux@gmail.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Discussion: https://postgr.es/m/CALzhyqwryL2QywgO03VQr_237Sq3MEVgTTT2_A9G3nGT5-SRZg@mail.gmail.com Backpatch-through: 18 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/9a60f295bcb186a729d04e76377b7f122b2a1dd9 Modified Files -------------- src/backend/optimizer/plan/analyzejoins.c | 119 +++++++++++++++++++++++++++--- src/test/regress/expected/join.out | 22 ++++++ src/test/regress/sql/join.sql | 12 +++ 3 files changed, 143 insertions(+), 10 deletions(-) ^ permalink raw reply [nested|flat] 5+ messages in thread
* pgsql: Strip removed-relation references from PlaceHolderVars at join r @ 2026-06-22 01:44 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 5+ messages in thread From: Richard Guo @ 2026-06-22 01:44 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Strip removed-relation references from PlaceHolderVars at join removal When left-join removal deletes a relation, remove_rel_from_query() updates the relid sets attached to RestrictInfos and EquivalenceMembers, and the canonical PlaceHolderVar held in each PlaceHolderInfo, but it does not rewrite the PlaceHolderVars embedded in clause and EquivalenceClass member expressions. That has been fine, because later processing consults those relid sets rather than the embedded PlaceHolderVars. However, such an expression may afterwards be translated for an appendrel child and have its relids recomputed from scratch by pull_varnos(). If the embedded PlaceHolderVar's phrels still mentions the removed relation, pull_varnos() folds it back in, so the rebuilt clause's relids reference a no-longer-existent relation. That yields a parameterized path keyed on the removed relation, tripping the Assert on root->outer_join_rels in get_eclass_indexes_for_relids(). Fix by stripping the removed relids from the PlaceHolderVars in surviving rels' baserestrictinfo and in EquivalenceClass member expressions, keeping them consistent with the canonical PlaceHolderVars. This is only reachable on v18 and later, where match_index_to_operand() began ignoring PlaceHolderVars; before that, the wrapping PlaceHolderVar prevented the index match that exposes the stale relids. Reported-by: Alexander Kuzmenkov <akuzmenkov@tigerdata.com> Author: Richard Guo <guofenglinux@gmail.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Discussion: https://postgr.es/m/CALzhyqwryL2QywgO03VQr_237Sq3MEVgTTT2_A9G3nGT5-SRZg@mail.gmail.com Backpatch-through: 18 Branch ------ REL_18_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/e0252679559adaeee16a7924430f542a1cad3ab7 Modified Files -------------- src/backend/optimizer/plan/analyzejoins.c | 121 +++++++++++++++++++++++++++--- src/test/regress/expected/join.out | 20 +++++ src/test/regress/sql/join.sql | 12 +++ 3 files changed, 143 insertions(+), 10 deletions(-) ^ permalink raw reply [nested|flat] 5+ messages in thread
* pgsql: Strip removed-relation references from PHVs in join clauses @ 2026-07-15 00:23 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 5+ messages in thread From: Richard Guo @ 2026-07-15 00:23 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Strip removed-relation references from PHVs in join clauses Commit 9a60f295b stripped the stale PlaceHolderVars left behind by left-join removal from the surviving rels' baserestrictinfo and from EquivalenceClass member expressions, but it overlooked join clauses. A PlaceHolderVar embedded in a join clause can likewise retain the removed rel and join in its phrels, since remove_rel_from_query() fixes up the RestrictInfo's own relid sets but not the PHVs inside its expression. As before, this is normally harmless, because later processing consults those relid sets rather than the embedded PHVs. However, a restriction clause derived from such an OR join clause inherits the stale PlaceHolderVar, and when the derived clause is translated for an appendrel child, pull_varnos() recomputes its relids and folds the removed relation back in. The rebuilt clause then references a no-longer-existent relation, tripping an assertion during path generation. Fix by also stripping the removed relation from the PlaceHolderVars in the surviving rels' join clauses, including the sub-clauses of any OR clause. Like 9a60f295b, this is only reachable on v18 and later, where match_index_to_operand() began ignoring PlaceHolderVars. Author: Arne Roland <arne.roland@malkut.net> Reviewed-by: Tender Wang <tndrwang@gmail.com> Reviewed-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://postgr.es/m/27a44087-3d65-473e-8d88-7c12228e0d7e@malkut.net Backpatch-through: 18 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/d68576bcfc7227d94c4391a3c34aadb8dbf8a3c7 Modified Files -------------- src/backend/optimizer/plan/analyzejoins.c | 78 +++++++++++++++++++++++++++++-- src/test/regress/expected/join.out | 12 +++++ src/test/regress/sql/join.sql | 7 +++ 3 files changed, 92 insertions(+), 5 deletions(-) ^ permalink raw reply [nested|flat] 5+ messages in thread
* pgsql: Strip removed-relation references from PHVs in join clauses @ 2026-07-15 00:23 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 5+ messages in thread From: Richard Guo @ 2026-07-15 00:23 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Strip removed-relation references from PHVs in join clauses Commit 9a60f295b stripped the stale PlaceHolderVars left behind by left-join removal from the surviving rels' baserestrictinfo and from EquivalenceClass member expressions, but it overlooked join clauses. A PlaceHolderVar embedded in a join clause can likewise retain the removed rel and join in its phrels, since remove_rel_from_query() fixes up the RestrictInfo's own relid sets but not the PHVs inside its expression. As before, this is normally harmless, because later processing consults those relid sets rather than the embedded PHVs. However, a restriction clause derived from such an OR join clause inherits the stale PlaceHolderVar, and when the derived clause is translated for an appendrel child, pull_varnos() recomputes its relids and folds the removed relation back in. The rebuilt clause then references a no-longer-existent relation, tripping an assertion during path generation. Fix by also stripping the removed relation from the PlaceHolderVars in the surviving rels' join clauses, including the sub-clauses of any OR clause. Like 9a60f295b, this is only reachable on v18 and later, where match_index_to_operand() began ignoring PlaceHolderVars. Author: Arne Roland <arne.roland@malkut.net> Reviewed-by: Tender Wang <tndrwang@gmail.com> Reviewed-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://postgr.es/m/27a44087-3d65-473e-8d88-7c12228e0d7e@malkut.net Backpatch-through: 18 Branch ------ REL_19_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/aae47813a14d1f5638469bda146d7839e39b7097 Modified Files -------------- src/backend/optimizer/plan/analyzejoins.c | 78 +++++++++++++++++++++++++++++-- src/test/regress/expected/join.out | 12 +++++ src/test/regress/sql/join.sql | 7 +++ 3 files changed, 92 insertions(+), 5 deletions(-) ^ permalink raw reply [nested|flat] 5+ messages in thread
* pgsql: Strip removed-relation references from PHVs in join clauses @ 2026-07-15 00:23 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 5+ messages in thread From: Richard Guo @ 2026-07-15 00:23 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Strip removed-relation references from PHVs in join clauses Commit 9a60f295b stripped the stale PlaceHolderVars left behind by left-join removal from the surviving rels' baserestrictinfo and from EquivalenceClass member expressions, but it overlooked join clauses. A PlaceHolderVar embedded in a join clause can likewise retain the removed rel and join in its phrels, since remove_rel_from_query() fixes up the RestrictInfo's own relid sets but not the PHVs inside its expression. As before, this is normally harmless, because later processing consults those relid sets rather than the embedded PHVs. However, a restriction clause derived from such an OR join clause inherits the stale PlaceHolderVar, and when the derived clause is translated for an appendrel child, pull_varnos() recomputes its relids and folds the removed relation back in. The rebuilt clause then references a no-longer-existent relation, tripping an assertion during path generation. Fix by also stripping the removed relation from the PlaceHolderVars in the surviving rels' join clauses, including the sub-clauses of any OR clause. Like 9a60f295b, this is only reachable on v18 and later, where match_index_to_operand() began ignoring PlaceHolderVars. Author: Arne Roland <arne.roland@malkut.net> Reviewed-by: Tender Wang <tndrwang@gmail.com> Reviewed-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://postgr.es/m/27a44087-3d65-473e-8d88-7c12228e0d7e@malkut.net Backpatch-through: 18 Branch ------ REL_18_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/18105e6db5e5314a575fdb23a99cf4809d8ef062 Modified Files -------------- src/backend/optimizer/plan/analyzejoins.c | 79 ++++++++++++++++++++++++++++--- src/test/regress/expected/join.out | 11 +++++ src/test/regress/sql/join.sql | 7 +++ 3 files changed, 91 insertions(+), 6 deletions(-) ^ permalink raw reply [nested|flat] 5+ messages in thread
end of thread, other threads:[~2026-07-15 00:23 UTC | newest] Thread overview: 5+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2026-06-22 01:44 pgsql: Strip removed-relation references from PlaceHolderVars at join r Richard Guo <rguo@postgresql.org> 2026-06-22 01:44 pgsql: Strip removed-relation references from PlaceHolderVars at join r Richard Guo <rguo@postgresql.org> 2026-07-15 00:23 pgsql: Strip removed-relation references from PHVs in join clauses Richard Guo <rguo@postgresql.org> 2026-07-15 00:23 pgsql: Strip removed-relation references from PHVs in join clauses Richard Guo <rguo@postgresql.org> 2026-07-15 00:23 pgsql: Strip removed-relation references from PHVs in join clauses Richard Guo <rguo@postgresql.org>
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