Skip to content
Snippets Groups Projects
Select Git revision
  • benchmark-tools
  • postgres-lambda
  • master default
  • REL9_4_25
  • REL9_5_20
  • REL9_6_16
  • REL_10_11
  • REL_11_6
  • REL_12_1
  • REL_12_0
  • REL_12_RC1
  • REL_12_BETA4
  • REL9_4_24
  • REL9_5_19
  • REL9_6_15
  • REL_10_10
  • REL_11_5
  • REL_12_BETA3
  • REL9_4_23
  • REL9_5_18
  • REL9_6_14
  • REL_10_9
  • REL_11_4
23 results
Compare
user avatar
Improve index-only scans to avoid repeated access to the index page.
Tom Lane authored 
We copy all the matched tuples off the page during _bt_readpage, instead of
expensively re-locking the page during each subsequent tuple fetch.  This
costs a bit more local storage, but not more than 2*BLCKSZ worth, and the
reduction in LWLock traffic is certainly worth that.  What's more, this
lets us get rid of the API wart in the original patch that said an index AM
could randomly decline to supply an index tuple despite having asserted
pg_am.amcanreturn.  That will be important for future improvements in the
index-only-scan feature, since the executor will now be able to rely on
having the index data available.
cbfa92c2
History
user avatar cbfa92c2
History
Name Last commit Last update
config
contrib
doc
src
.gitignore
COPYRIGHT
GNUmakefile.in
Makefile
README
README.git
aclocal.m4
configure
configure.in
README
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:

	http://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.  Changes between all PostgreSQL releases are recorded in the
file HISTORY.  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
http://www.postgresql.org/download/.  For more information look at our
web site located at http://www.postgresql.org/.