Tomas Vondra cb0ad70b8e Keep the decompressed filter in brin_bloom_union
The brin_bloom_union() function combines two BRIN summaries, by merging
one filter into the other. With bloom, we have to decompress the filters
first, but the function failed to update the summary to store the merged
filter. As a consequence, the index may be missing some of the data, and
return false negatives.

This issue exists since BRIN bloom indexes were introduced in Postgres
14, but at that point the union function was called only when two
sessions happened to summarize a range concurrently, which is rare. It
got much easier to hit in 17, as parallel builds use the union function
to merge summaries built by workers.

Fixed by storing a pointer to the decompressed filter, and freeing the
original one. Free the second filter too, if it was decompressed. The
freeing is not strictly necessary, because the union is called in
short-lived contexts, but it's tidy.

Backpatch to 14, where BRIN bloom indexes were introduced.

Reported by Arseniy Mukhin, investigation and fix by me.

Reported-by: Arseniy Mukhin
Discussion: https://postgr.es/m/18855-1cf1c8bcc22150e6%40postgresql.org
Backpatch-through: 14
2025-03-26 17:02:17 +01:00
2025-03-05 10:29:08 -05:00
2019-12-18 09:13:13 +01:00
2022-12-04 15:23:00 -05:00
2025-02-17 16:11:21 -05:00
2025-02-17 16:11:21 -05:00
2025-01-01 11:21:54 -05:00
2020-02-10 20:47:50 +01:00

PostgreSQL Database Management System

This directory contains the source code distribution of the PostgreSQL database management system.

PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.

Copyright and license information can be found in the file COPYRIGHT.

General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/17/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/17/installation.html.

The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.

Description
he World's Most Advanced Open Source Relational Database.
Readme 744 MiB
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