Go to file
Thomas Munro d061ea21fc Adjust DSM and DSA slot usage constants.
When running a lot of large parallel queries concurrently, or a plan with
a lot of separate Gather nodes, it is possible to run out of DSM slots.
There are better solutions to these problems requiring architectural
redesign work, but for now, let's adjust the constants so that it's more
difficult to hit the limit.

1.  Previously, a DSA area would create up to four segments at each size
before doubling the size.  After this commit, it will create only two at
each size, so it ramps up faster and therefore needs fewer slots.

2.  Previously, the total limit on DSM slots allowed for 2 per connection.
Switch to 5 per connection.

Also remove an obsolete nearby comment.

Author: Thomas Munro
Reviewed-by: Robert Haas, Andres Freund
Discussion: https://postre.es/m/CA%2BhUKGL6H2BpGbiF7Lj6QiTjTGyTLW_vLR%3DSn2tEBeTcYXiMKw%40mail.gmail.com
2020-01-31 17:29:38 +13:00
config Add configure probe for rl_completion_suppress_quote. 2020-01-23 18:20:57 -05:00
contrib In jsonb_plpython.c, suppress warning message from gcc 10. 2020-01-30 18:26:12 -05:00
doc Fix slot data persistency when advancing physical replication slots 2020-01-30 11:14:02 +09:00
src Adjust DSM and DSA slot usage constants. 2020-01-31 17:29:38 +13:00
.dir-locals.el Make Emacs perl-mode indent more like perltidy. 2019-01-13 11:32:31 -08:00
.editorconfig Add .editorconfig 2019-12-18 09:13:13 +01:00
.gitattributes gitattributes: Add new file 2019-11-12 08:13:55 +01:00
.gitignore Support for optimizing and emitting code in LLVM JIT provider. 2018-03-22 11:05:22 -07:00
aclocal.m4 Fix configure's AC_CHECK_DECLS tests to work correctly with clang. 2018-11-19 12:01:47 -05:00
configure Add configure probe for rl_completion_suppress_quote. 2020-01-23 18:20:57 -05:00
configure.in Improve psql's tab completion for filenames. 2020-01-23 11:07:12 -05:00
COPYRIGHT Update copyrights for 2020 2020-01-01 12:21:45 -05:00
GNUmakefile.in Add support for automatically updating Unicode derived files 2020-01-09 10:08:14 +01:00
HISTORY Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
Makefile Don't unset MAKEFLAGS in non-GNU Makefile. 2019-06-25 09:36:21 +12:00
README Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
README.git Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00

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.

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/.