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Tom Lane c106ef0807 Use BumpContext contexts in TupleHashTables, and do some code cleanup. For all extant uses of TupleHashTables, execGrouping.c itself does nothing with the "tablecxt" except to allocate new hash entries in it, and the callers do nothing with it except to reset the whole context. So this is an ideal use-case for a BumpContext, and the hash tables are frequently big enough for the savings to be significant. (Commit `cc721c459` already taught nodeAgg.c this idea, but neglected the other callers of BuildTupleHashTable.) While at it, let's clean up some ill-advised leftovers from rebasing TupleHashTables on simplehash.h: * Many comments and variable names were based on the idea that the tablecxt holds the whole TupleHashTable, whereas now it only holds the hashed tuples (plus any caller-defined "additional storage"). Rename to names like tuplescxt and tuplesContext, and adjust the comments. Also adjust the memory context names to be like "<Foo> hashed tuples". * Make ResetTupleHashTable() reset the tuplescxt rather than relying on the caller to do so; that was fairly bizarre and seems like a recipe for leaks. This is less efficient in the case where nodeAgg.c uses the same tuplescxt for several different hashtables, but only microscopically so because mcxt.c will short-circuit the extra resets via its isReset flag. I judge the extra safety and intellectual cleanliness well worth those few cycles. * Remove the long-obsolete "allow_jit" check added by ac88807f9; instead, just Assert that metacxt and tuplescxt are different. We need that anyway for this definition of ResetTupleHashTable() to be safe. There is a side issue of the extent to which this change invalidates the planner's estimates of hashtable memory consumption. However, those estimates are already pretty bad, so improving them seems like it can be a separate project. This change is useful to do first to establish consistent executor behavior that the planner can expect. A loose end not addressed here is that the "entrysize" calculation in BuildTupleHashTable seems wrong: "sizeof(TupleHashEntryData) + additionalsize" corresponds neither to the size of the simplehash entries nor to the total space needed per tuple. It's questionable why BuildTupleHashTable is second-guessing its caller's nbuckets choice at all, since the original source of the number should have had more information. But that all seems wrapped up with the planner's estimation logic, so let's leave it for the planned followup patch. Reported-by: Jeff Janes <jeff.janes@gmail.com> Reported-by: David Rowley <dgrowleyml@gmail.com> Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: David Rowley <dgrowleyml@gmail.com> Discussion: https://postgr.es/m/CAMkU=1zia0JfW_QR8L5xA2vpa0oqVuiapm78h=WpNsHH13_9uw@mail.gmail.com Discussion: https://postgr.es/m/2268409.1761512111@sss.pgh.pa.us		2025-10-30 11:21:22 -04:00
.github	Add CODE_OF_CONDUCT.md, CONTRIBUTING.md, and SECURITY.md.	2024-07-02 13:03:58 -05:00
config	Remove traces of support for Sun Studio compiler	2025-09-12 07:39:05 +02:00
contrib	Fix some confusing uses of const	2025-10-30 11:20:04 +01:00
doc	docs: Link to the correct protocol version inspection function	2025-10-30 10:59:56 +01:00
src	Use BumpContext contexts in TupleHashTables, and do some code cleanup.	2025-10-30 11:21:22 -04:00
.cirrus.star	ci: Simplify ci-os-only handling	2025-08-14 12:09:34 -04:00
.cirrus.tasks.yml	Revert "Improve docs syntax checking"	2025-10-06 07:53:31 -04:00
.cirrus.yml	ci: Per-repo configuration for manually trigger tasks	2025-08-14 11:54:03 -04:00
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aclocal.m4	autoconf: Move export_dynamic determination to configure	2022-12-06 18:55:28 -08:00
configure	Use C11 char16_t and char32_t for Unicode code points.	2025-10-29 14:17:13 -07:00
configure.ac	Use C11 char16_t and char32_t for Unicode code points.	2025-10-29 14:17:13 -07:00
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README.md	Revise the style of a paragraph in README.md.	2024-03-21 10:16:41 -05:00

README.md

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.

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