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pgsql: Fix generation of EC join conditions at the wrong plan level. 4+ messages / 1 participants [nested] [flat]
* pgsql: Fix generation of EC join conditions at the wrong plan level. @ 2024-04-16 15:23 Tom Lane <tgl@sss.pgh.pa.us> 0 siblings, 0 replies; 4+ messages in thread From: Tom Lane @ 2024-04-16 15:23 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix generation of EC join conditions at the wrong plan level. get_baserel_parampathinfo previously assumed without checking that the results of generate_join_implied_equalities "necessarily satisfy join_clause_is_movable_into". This turns out to be wrong in the presence of outer joins, because the generated clauses could include Vars that mustn't be evaluated below a relevant outer join. That led to applying clauses at the wrong plan level and possibly getting incorrect query results. We must check each clause's nullable_relids, and really the right thing to do is test join_clause_is_movable_into. However, trying to fix it that way exposes an oversight in equivclass.c: it wasn't careful about marking join clauses for appendrel children with the correct clause_relids. That caused the modified get_baserel_parampathinfo code to reject some clauses it still needs to accept. (See parallel commit for HEAD/v16 for more commentary about that.) Per bug #18429 from Benoît Ryder. This misbehavior existed for a long time before commit 2489d76c4, so patch v12-v15 this way. Discussion: https://postgr.es/m/18429-8982d4a348cc86c6@postgresql.org Branch ------ REL_15_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/5aacfa64e5dae1a26a5ad5192877683695de2e77 Modified Files -------------- src/backend/optimizer/path/equivclass.c | 15 +++++++++++++++ src/backend/optimizer/util/relnode.c | 25 ++++++++++++++++++------- src/test/regress/expected/join.out | 31 +++++++++++++++++++++++++++++++ src/test/regress/sql/join.sql | 19 +++++++++++++++++++ 4 files changed, 83 insertions(+), 7 deletions(-) ^ permalink raw reply [nested|flat] 4+ messages in thread
* pgsql: Fix generation of EC join conditions at the wrong plan level. @ 2024-04-16 15:23 Tom Lane <tgl@sss.pgh.pa.us> 0 siblings, 0 replies; 4+ messages in thread From: Tom Lane @ 2024-04-16 15:23 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix generation of EC join conditions at the wrong plan level. get_baserel_parampathinfo previously assumed without checking that the results of generate_join_implied_equalities "necessarily satisfy join_clause_is_movable_into". This turns out to be wrong in the presence of outer joins, because the generated clauses could include Vars that mustn't be evaluated below a relevant outer join. That led to applying clauses at the wrong plan level and possibly getting incorrect query results. We must check each clause's nullable_relids, and really the right thing to do is test join_clause_is_movable_into. However, trying to fix it that way exposes an oversight in equivclass.c: it wasn't careful about marking join clauses for appendrel children with the correct clause_relids. That caused the modified get_baserel_parampathinfo code to reject some clauses it still needs to accept. (See parallel commit for HEAD/v16 for more commentary about that.) Per bug #18429 from Benoît Ryder. This misbehavior existed for a long time before commit 2489d76c4, so patch v12-v15 this way. Discussion: https://postgr.es/m/18429-8982d4a348cc86c6@postgresql.org Branch ------ REL_13_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/d9e4ee74f48c4478bf644be166188e00af1f9158 Modified Files -------------- src/backend/optimizer/path/equivclass.c | 15 +++++++++++++++ src/backend/optimizer/util/relnode.c | 25 ++++++++++++++++++------- src/test/regress/expected/join.out | 31 +++++++++++++++++++++++++++++++ src/test/regress/sql/join.sql | 19 +++++++++++++++++++ 4 files changed, 83 insertions(+), 7 deletions(-) ^ permalink raw reply [nested|flat] 4+ messages in thread
* pgsql: Fix generation of EC join conditions at the wrong plan level. @ 2024-04-16 15:23 Tom Lane <tgl@sss.pgh.pa.us> 0 siblings, 0 replies; 4+ messages in thread From: Tom Lane @ 2024-04-16 15:23 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix generation of EC join conditions at the wrong plan level. get_baserel_parampathinfo previously assumed without checking that the results of generate_join_implied_equalities "necessarily satisfy join_clause_is_movable_into". This turns out to be wrong in the presence of outer joins, because the generated clauses could include Vars that mustn't be evaluated below a relevant outer join. That led to applying clauses at the wrong plan level and possibly getting incorrect query results. We must check each clause's nullable_relids, and really the right thing to do is test join_clause_is_movable_into. However, trying to fix it that way exposes an oversight in equivclass.c: it wasn't careful about marking join clauses for appendrel children with the correct clause_relids. That caused the modified get_baserel_parampathinfo code to reject some clauses it still needs to accept. (See parallel commit for HEAD/v16 for more commentary about that.) Per bug #18429 from Benoît Ryder. This misbehavior existed for a long time before commit 2489d76c4, so patch v12-v15 this way. Discussion: https://postgr.es/m/18429-8982d4a348cc86c6@postgresql.org Branch ------ REL_14_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/ab2402268c04401533f163d959cdccd0e124f526 Modified Files -------------- src/backend/optimizer/path/equivclass.c | 15 +++++++++++++++ src/backend/optimizer/util/relnode.c | 25 ++++++++++++++++++------- src/test/regress/expected/join.out | 31 +++++++++++++++++++++++++++++++ src/test/regress/sql/join.sql | 19 +++++++++++++++++++ 4 files changed, 83 insertions(+), 7 deletions(-) ^ permalink raw reply [nested|flat] 4+ messages in thread
* pgsql: Fix generation of EC join conditions at the wrong plan level. @ 2024-04-16 15:23 Tom Lane <tgl@sss.pgh.pa.us> 0 siblings, 0 replies; 4+ messages in thread From: Tom Lane @ 2024-04-16 15:23 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix generation of EC join conditions at the wrong plan level. get_baserel_parampathinfo previously assumed without checking that the results of generate_join_implied_equalities "necessarily satisfy join_clause_is_movable_into". This turns out to be wrong in the presence of outer joins, because the generated clauses could include Vars that mustn't be evaluated below a relevant outer join. That led to applying clauses at the wrong plan level and possibly getting incorrect query results. We must check each clause's nullable_relids, and really the right thing to do is test join_clause_is_movable_into. However, trying to fix it that way exposes an oversight in equivclass.c: it wasn't careful about marking join clauses for appendrel children with the correct clause_relids. That caused the modified get_baserel_parampathinfo code to reject some clauses it still needs to accept. (See parallel commit for HEAD/v16 for more commentary about that.) Per bug #18429 from Benoît Ryder. This misbehavior existed for a long time before commit 2489d76c4, so patch v12-v15 this way. Discussion: https://postgr.es/m/18429-8982d4a348cc86c6@postgresql.org Branch ------ REL_12_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/f502849d49a4744a8b6ce8abaf7af7c320c4ea0b Modified Files -------------- src/backend/optimizer/path/equivclass.c | 15 +++++++++++++++ src/backend/optimizer/util/relnode.c | 25 ++++++++++++++++++------- src/test/regress/expected/join.out | 31 +++++++++++++++++++++++++++++++ src/test/regress/sql/join.sql | 19 +++++++++++++++++++ 4 files changed, 83 insertions(+), 7 deletions(-) ^ permalink raw reply [nested|flat] 4+ messages in thread
end of thread, other threads:[~2024-04-16 15:23 UTC | newest] Thread overview: 4+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2024-04-16 15:23 pgsql: Fix generation of EC join conditions at the wrong plan level. Tom Lane <tgl@sss.pgh.pa.us> 2024-04-16 15:23 pgsql: Fix generation of EC join conditions at the wrong plan level. Tom Lane <tgl@sss.pgh.pa.us> 2024-04-16 15:23 pgsql: Fix generation of EC join conditions at the wrong plan level. Tom Lane <tgl@sss.pgh.pa.us> 2024-04-16 15:23 pgsql: Fix generation of EC join conditions at the wrong plan level. Tom Lane <tgl@sss.pgh.pa.us>
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