postgres

History

Dean Rasheed b880d9a025 Avoid rewriting data-modifying CTEs more than once. Formerly, when updating an auto-updatable view, or a relation with rules, if the original query had any data-modifying CTEs, the rewriter would rewrite those CTEs multiple times as RewriteQuery() recursed into the product queries. In most cases that was harmless, because RewriteQuery() is mostly idempotent. However, if the CTE involved updating an always-generated column, it would trigger an error because any subsequent rewrite would appear to be attempting to assign a non-default value to the always-generated column. This could perhaps be fixed by attempting to make RewriteQuery() fully idempotent, but that looks quite tricky to achieve, and would probably be quite fragile, given that more generated-column-type features might be added in the future. Instead, fix by arranging for RewriteQuery() to rewrite each CTE exactly once (by tracking the number of CTEs already rewritten as it recurses). This has the advantage of being simpler and more efficient, but it does make RewriteQuery() dependent on the order in which rewriteRuleAction() joins the CTE lists from the original query and the rule action, so care must be taken if that is ever changed. Reported-by: Bernice Southey <bernice.southey@gmail.com> Author: Bernice Southey <bernice.southey@gmail.com> Author: Dean Rasheed <dean.a.rasheed@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Kirill Reshke <reshkekirill@gmail.com> Discussion: https://postgr.es/m/CAEDh4nyD6MSH9bROhsOsuTqGAv_QceU_GDvN9WcHLtZTCYM1kA@mail.gmail.com Backpatch-through: 14		4 weeks ago
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backend	Avoid rewriting data-modifying CTEs more than once.	4 weeks ago
bin	pg_dump tests: don't put dumps in stdout	1 month ago
common	Don't put library-supplied -L/-I switches before user-supplied ones.	5 months ago
fe_utils	Fix bug in archive streamer with LZ4 decompression	6 months ago
include	Fix incorrect IndexOptInfo header comment	1 month ago
interfaces	Fix typo	1 month ago
makefiles	pgxs.mk: remove unreachable rule for deleting regress.def.	6 months ago
pl	Translation updates	2 months ago
port	Handle EPERM in pg_numa_init	1 month ago
template	…
test	Avoid rewriting data-modifying CTEs more than once.	4 weeks ago
timezone	…
tools	Change coding pattern for CURL_IGNORE_DEPRECATION()	2 months ago
tutorial	…
.gitignore	…
DEVELOPERS	…
Makefile	…
Makefile.global.in	Don't put library-supplied -L/-I switches before user-supplied ones.	5 months ago
Makefile.shlib	…
meson.build	…
nls-global.mk	Fix update-po for the PGXS case	2 months ago