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pgsql: Fix incorrect NEW references to generated columns in rule rewrit 6+ messages / 1 participants [nested] [flat]
* pgsql: Fix incorrect NEW references to generated columns in rule rewrit @ 2026-04-21 05:36 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 6+ messages in thread From: Richard Guo @ 2026-04-21 05:36 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix incorrect NEW references to generated columns in rule rewriting When a rule action or rule qualification references NEW.col where col is a generated column (stored or virtual), the rewriter produces incorrect results. rewriteTargetListIU removes generated columns from the query's target list, since stored generated columns are recomputed by the executor and virtual ones store nothing. However, ReplaceVarsFromTargetList then cannot find these columns when resolving NEW references during rule rewriting. For UPDATE, the REPLACEVARS_CHANGE_VARNO fallback redirects NEW.col to the original target relation, making it read the pre-update value (same as OLD.col). For INSERT, REPLACEVARS_SUBSTITUTE_NULL replaces it with NULL. Both are wrong when the generated column depends on columns being modified. Fix by building target list entries for generated columns from their generation expressions, pre-resolving the NEW.attribute references within those expressions against the query's targetlist, and passing them together with the query's targetlist to ReplaceVarsFromTargetList. Back-patch to all supported branches. Virtual generated columns were added in v18, so the back-patches in pre-v18 branches only handle stored generated columns. Reported-by: SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Author: Dean Rasheed <dean.a.rasheed@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com> Discussion: https://postgr.es/m/CAHg+QDexGTmCZzx=73gXkY2ZADS6LRhpnU+-8Y_QmrdTS6yUhA@mail.gmail.com Backpatch-through: 14 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/c6a79be3f3c78a1ab2b4ae8842451c72e0a8e6f3 Modified Files -------------- src/backend/rewrite/rewriteHandler.c | 145 +++++++++++++++++------- src/test/regress/expected/generated_stored.out | 34 ++++++ src/test/regress/expected/generated_virtual.out | 34 ++++++ src/test/regress/sql/generated_stored.sql | 23 ++++ src/test/regress/sql/generated_virtual.sql | 23 ++++ 5 files changed, 221 insertions(+), 38 deletions(-) ^ permalink raw reply [nested|flat] 6+ messages in thread
* pgsql: Fix incorrect NEW references to generated columns in rule rewrit @ 2026-04-21 05:36 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 6+ messages in thread From: Richard Guo @ 2026-04-21 05:36 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix incorrect NEW references to generated columns in rule rewriting When a rule action or rule qualification references NEW.col where col is a generated column (stored or virtual), the rewriter produces incorrect results. rewriteTargetListIU removes generated columns from the query's target list, since stored generated columns are recomputed by the executor and virtual ones store nothing. However, ReplaceVarsFromTargetList then cannot find these columns when resolving NEW references during rule rewriting. For UPDATE, the REPLACEVARS_CHANGE_VARNO fallback redirects NEW.col to the original target relation, making it read the pre-update value (same as OLD.col). For INSERT, REPLACEVARS_SUBSTITUTE_NULL replaces it with NULL. Both are wrong when the generated column depends on columns being modified. Fix by building target list entries for generated columns from their generation expressions, pre-resolving the NEW.attribute references within those expressions against the query's targetlist, and passing them together with the query's targetlist to ReplaceVarsFromTargetList. Back-patch to all supported branches. Virtual generated columns were added in v18, so the back-patches in pre-v18 branches only handle stored generated columns. Reported-by: SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Author: Dean Rasheed <dean.a.rasheed@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com> Discussion: https://postgr.es/m/CAHg+QDexGTmCZzx=73gXkY2ZADS6LRhpnU+-8Y_QmrdTS6yUhA@mail.gmail.com Backpatch-through: 14 Branch ------ REL_18_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/e528bfe971900fcd1a74da53931ade4c06eca662 Modified Files -------------- src/backend/rewrite/rewriteHandler.c | 145 +++++++++++++++++------- src/test/regress/expected/generated_stored.out | 34 ++++++ src/test/regress/expected/generated_virtual.out | 34 ++++++ src/test/regress/sql/generated_stored.sql | 23 ++++ src/test/regress/sql/generated_virtual.sql | 23 ++++ 5 files changed, 221 insertions(+), 38 deletions(-) ^ permalink raw reply [nested|flat] 6+ messages in thread
* pgsql: Fix incorrect NEW references to generated columns in rule rewrit @ 2026-04-21 05:36 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 6+ messages in thread From: Richard Guo @ 2026-04-21 05:36 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix incorrect NEW references to generated columns in rule rewriting When a rule action or rule qualification references NEW.col where col is a generated column (stored or virtual), the rewriter produces incorrect results. rewriteTargetListIU removes generated columns from the query's target list, since stored generated columns are recomputed by the executor and virtual ones store nothing. However, ReplaceVarsFromTargetList then cannot find these columns when resolving NEW references during rule rewriting. For UPDATE, the REPLACEVARS_CHANGE_VARNO fallback redirects NEW.col to the original target relation, making it read the pre-update value (same as OLD.col). For INSERT, REPLACEVARS_SUBSTITUTE_NULL replaces it with NULL. Both are wrong when the generated column depends on columns being modified. Fix by building target list entries for generated columns from their generation expressions, pre-resolving the NEW.attribute references within those expressions against the query's targetlist, and passing them together with the query's targetlist to ReplaceVarsFromTargetList. Back-patch to all supported branches. Virtual generated columns were added in v18, so the back-patches in pre-v18 branches only handle stored generated columns. Reported-by: SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Author: Dean Rasheed <dean.a.rasheed@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com> Discussion: https://postgr.es/m/CAHg+QDexGTmCZzx=73gXkY2ZADS6LRhpnU+-8Y_QmrdTS6yUhA@mail.gmail.com Backpatch-through: 14 Branch ------ REL_17_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/9d6208939a0ad05171e37a106f02c55a591a26f1 Modified Files -------------- src/backend/rewrite/rewriteHandler.c | 134 ++++++++++++++++++++++++++++++-- src/test/regress/expected/generated.out | 34 ++++++++ src/test/regress/sql/generated.sql | 24 ++++++ 3 files changed, 187 insertions(+), 5 deletions(-) ^ permalink raw reply [nested|flat] 6+ messages in thread
* pgsql: Fix incorrect NEW references to generated columns in rule rewrit @ 2026-04-21 05:36 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 6+ messages in thread From: Richard Guo @ 2026-04-21 05:36 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix incorrect NEW references to generated columns in rule rewriting When a rule action or rule qualification references NEW.col where col is a generated column (stored or virtual), the rewriter produces incorrect results. rewriteTargetListIU removes generated columns from the query's target list, since stored generated columns are recomputed by the executor and virtual ones store nothing. However, ReplaceVarsFromTargetList then cannot find these columns when resolving NEW references during rule rewriting. For UPDATE, the REPLACEVARS_CHANGE_VARNO fallback redirects NEW.col to the original target relation, making it read the pre-update value (same as OLD.col). For INSERT, REPLACEVARS_SUBSTITUTE_NULL replaces it with NULL. Both are wrong when the generated column depends on columns being modified. Fix by building target list entries for generated columns from their generation expressions, pre-resolving the NEW.attribute references within those expressions against the query's targetlist, and passing them together with the query's targetlist to ReplaceVarsFromTargetList. Back-patch to all supported branches. Virtual generated columns were added in v18, so the back-patches in pre-v18 branches only handle stored generated columns. Reported-by: SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Author: Dean Rasheed <dean.a.rasheed@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com> Discussion: https://postgr.es/m/CAHg+QDexGTmCZzx=73gXkY2ZADS6LRhpnU+-8Y_QmrdTS6yUhA@mail.gmail.com Backpatch-through: 14 Branch ------ REL_16_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/07b257189ea4fc949a36fd341ba2ba6b49e5f718 Modified Files -------------- src/backend/rewrite/rewriteHandler.c | 134 ++++++++++++++++++++++++++++++-- src/test/regress/expected/generated.out | 34 ++++++++ src/test/regress/sql/generated.sql | 24 ++++++ 3 files changed, 187 insertions(+), 5 deletions(-) ^ permalink raw reply [nested|flat] 6+ messages in thread
* pgsql: Fix incorrect NEW references to generated columns in rule rewrit @ 2026-04-21 05:36 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 6+ messages in thread From: Richard Guo @ 2026-04-21 05:36 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix incorrect NEW references to generated columns in rule rewriting When a rule action or rule qualification references NEW.col where col is a generated column (stored or virtual), the rewriter produces incorrect results. rewriteTargetListIU removes generated columns from the query's target list, since stored generated columns are recomputed by the executor and virtual ones store nothing. However, ReplaceVarsFromTargetList then cannot find these columns when resolving NEW references during rule rewriting. For UPDATE, the REPLACEVARS_CHANGE_VARNO fallback redirects NEW.col to the original target relation, making it read the pre-update value (same as OLD.col). For INSERT, REPLACEVARS_SUBSTITUTE_NULL replaces it with NULL. Both are wrong when the generated column depends on columns being modified. Fix by building target list entries for generated columns from their generation expressions, pre-resolving the NEW.attribute references within those expressions against the query's targetlist, and passing them together with the query's targetlist to ReplaceVarsFromTargetList. Back-patch to all supported branches. Virtual generated columns were added in v18, so the back-patches in pre-v18 branches only handle stored generated columns. Reported-by: SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Author: Dean Rasheed <dean.a.rasheed@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com> Discussion: https://postgr.es/m/CAHg+QDexGTmCZzx=73gXkY2ZADS6LRhpnU+-8Y_QmrdTS6yUhA@mail.gmail.com Backpatch-through: 14 Branch ------ REL_15_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/7062bd577ec98d1e6f6a0fb7c8b859d0c32a6061 Modified Files -------------- src/backend/rewrite/rewriteHandler.c | 134 ++++++++++++++++++++++++++++++-- src/test/regress/expected/generated.out | 34 ++++++++ src/test/regress/sql/generated.sql | 24 ++++++ 3 files changed, 187 insertions(+), 5 deletions(-) ^ permalink raw reply [nested|flat] 6+ messages in thread
* pgsql: Fix incorrect NEW references to generated columns in rule rewrit @ 2026-04-21 05:36 Richard Guo <rguo@postgresql.org> 0 siblings, 0 replies; 6+ messages in thread From: Richard Guo @ 2026-04-21 05:36 UTC (permalink / raw) To: pgsql-committers@lists.postgresql.org Fix incorrect NEW references to generated columns in rule rewriting When a rule action or rule qualification references NEW.col where col is a generated column (stored or virtual), the rewriter produces incorrect results. rewriteTargetListIU removes generated columns from the query's target list, since stored generated columns are recomputed by the executor and virtual ones store nothing. However, ReplaceVarsFromTargetList then cannot find these columns when resolving NEW references during rule rewriting. For UPDATE, the REPLACEVARS_CHANGE_VARNO fallback redirects NEW.col to the original target relation, making it read the pre-update value (same as OLD.col). For INSERT, REPLACEVARS_SUBSTITUTE_NULL replaces it with NULL. Both are wrong when the generated column depends on columns being modified. Fix by building target list entries for generated columns from their generation expressions, pre-resolving the NEW.attribute references within those expressions against the query's targetlist, and passing them together with the query's targetlist to ReplaceVarsFromTargetList. Back-patch to all supported branches. Virtual generated columns were added in v18, so the back-patches in pre-v18 branches only handle stored generated columns. Reported-by: SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Author: Dean Rasheed <dean.a.rasheed@gmail.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com> Discussion: https://postgr.es/m/CAHg+QDexGTmCZzx=73gXkY2ZADS6LRhpnU+-8Y_QmrdTS6yUhA@mail.gmail.com Backpatch-through: 14 Branch ------ REL_14_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/8e39951beac7ae361f742022d0060b1ce3ba99e8 Modified Files -------------- src/backend/rewrite/rewriteHandler.c | 134 ++++++++++++++++++++++++++++++-- src/test/regress/expected/generated.out | 34 ++++++++ src/test/regress/sql/generated.sql | 24 ++++++ 3 files changed, 187 insertions(+), 5 deletions(-) ^ permalink raw reply [nested|flat] 6+ messages in thread
end of thread, other threads:[~2026-04-21 05:36 UTC | newest] Thread overview: 6+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2026-04-21 05:36 pgsql: Fix incorrect NEW references to generated columns in rule rewrit Richard Guo <rguo@postgresql.org> 2026-04-21 05:36 pgsql: Fix incorrect NEW references to generated columns in rule rewrit Richard Guo <rguo@postgresql.org> 2026-04-21 05:36 pgsql: Fix incorrect NEW references to generated columns in rule rewrit Richard Guo <rguo@postgresql.org> 2026-04-21 05:36 pgsql: Fix incorrect NEW references to generated columns in rule rewrit Richard Guo <rguo@postgresql.org> 2026-04-21 05:36 pgsql: Fix incorrect NEW references to generated columns in rule rewrit Richard Guo <rguo@postgresql.org> 2026-04-21 05:36 pgsql: Fix incorrect NEW references to generated columns in rule rewrit Richard Guo <rguo@postgresql.org>
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