From 2fbbe428c25d7d12ad7d818ef5d00fe7c8085433 Mon Sep 17 00:00:00 2001 From: EC2 Default User Date: Mon, 24 Apr 2023 16:04:45 +0000 Subject: [PATCH 1/1] Fix documentation for work_mem A couple of small documentation fixes to clear up terminology used in the work_mem documentation. The removal of the usage of "parallel" as it does not refer to parallel query in the context of work_mem. Also, a clarification on the memory used by hash tables. Discussion: https://www.postgresql.org/message-id/flat/66590882-F48C-4A25-83E3-73792CF8C51F%40amazon.com --- doc/src/sgml/config.sgml | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 091a79d4f3..bafda1c53a 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1897,8 +1897,9 @@ include_dir 'conf.d' (such as a sort or hash table) before writing to temporary disk files. If this value is specified without units, it is taken as kilobytes. The default value is four megabytes (4MB). - Note that for a complex query, several sort or hash operations might be - running in parallel; each operation will generally be allowed + Note that a complex query may include several sort and hash operations, + and more than one of these operations may be in progress simultaneously + for a given query execution; each such operation will generally be allowed to use as much memory as this value specifies before it starts to write data into temporary files. Also, several running sessions could be doing such operations concurrently. @@ -1914,7 +1915,7 @@ include_dir 'conf.d' Hash-based operations are generally more sensitive to memory availability than equivalent sort-based operations. The - memory available for hash tables is computed by multiplying + memory limit for hash tables is computed by multiplying work_mem by hash_mem_multiplier. This makes it possible for hash-based operations to use an amount of memory -- 2.39.2