Go to file
Nathan Bossart 9bfd44bbde Convert pg_restore's ready_list to a priority queue.
Presently, parallel restores spend a lot of time sorting this list
so that we pick the largest items first.  With many tables, this
sorting can become a significant bottleneck.  There are a couple of
reports from the field about this, and it is easy to reproduce.

This commit improves the performance of parallel pg_restore with
many tables by converting its ready_list to a priority queue, i.e.,
a binary heap.  We will first try to run the highest priority item,
but if it cannot be chosen due to the lock heuristic, we'll do a
sequential scan through the heap nodes until we find one that is
runnable.  This means that we might end up picking an item with a
much lower priority.  However, we expect that we will typically be
able to pick one of the first few items, which should usually have
a relatively high priority.

Suggested-by: Tom Lane
Tested-by: Pierre Ducroquet
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/3612876.1689443232%40sss.pgh.pa.us
2023-09-19 14:31:29 -07:00
config Use native CRC instructions on 64-bit LoongArch 2023-08-10 11:36:15 +07:00
contrib Fix tracking of temp table relation extensions as writes 2023-09-13 19:14:09 -07:00
doc Don't crash if cursor_to_xmlschema is used on a non-data-returning Portal. 2023-09-18 14:28:17 -04:00
src Convert pg_restore's ready_list to a priority queue. 2023-09-19 14:31:29 -07:00
.cirrus.star ci: Prepare to make compute resources for CI configurable 2023-08-23 15:15:28 -07:00
.cirrus.tasks.yml Use "template" data directory in tests 2023-08-24 14:38:02 -07:00
.cirrus.yml ci: Make compute resources for CI configurable 2023-08-23 15:15:28 -07:00
.dir-locals.el
.editorconfig
.git-blame-ignore-revs Add bc6041b61f to .git-blame-ignore-revs. 2023-08-30 16:06:12 +09:00
.gitattributes
.gitignore
aclocal.m4
configure Remove traces of Sun -lposix4. 2023-08-17 16:16:43 +12:00
configure.ac Remove traces of Sun -lposix4. 2023-08-17 16:16:43 +12:00
COPYRIGHT
GNUmakefile.in
HISTORY
Makefile
meson_options.txt
meson.build Generate a locale-agnostic initdb template 2023-08-29 18:06:55 +02:00
README
README.git

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.

PostgreSQL has many language interfaces, many of which are listed here:

	https://www.postgresql.org/download/

See the file INSTALL for instructions on how to build and install
PostgreSQL.  That file also lists supported operating systems and
hardware platforms and contains information regarding any other
software packages that are required to build or run the PostgreSQL
system.  Copyright and license information can be found in the
file COPYRIGHT.  A comprehensive documentation set is included in this
distribution; it can be read as described in the installation
instructions.

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