Adds --clone/--copy-file-range options to pg_combinebackup, to allow copying files using file cloning or copy_file_range(). These methods may be faster than the standard block-by-block copy, but the main advantage is that they enable various features provided by CoW filesystems. This commit only uses these copy methods for files that did not change and can be copied as a whole from a single backup. These new copy methods may not be available on all platforms, in which case the command throws an error (immediately, even if no files would be copied as a whole). This early failure seems better than failing later when trying to copy the first file, after performing a lot of work on earlier files. If the requested copy method is available, but a checksum needs to be recalculated (e.g. because of a different checksum type), the file is still copied using the requested method, but it is also read for the checksum calculation. Depending on the filesystem this may be more expensive than just performing the simple copy, but it does enable the CoW benefits. Initial patch by Jakub Wartak, various reworks and improvements by me. Author: Tomas Vondra, Jakub Wartak Reviewed-by: Thomas Munro, Jakub Wartak, Robert Haas Discussion: https://postgr.es/m/3024283a-7491-4240-80d0-421575f6bb23%40enterprisedb.com |
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config | ||
contrib | ||
doc | ||
src | ||
.cirrus.star | ||
.cirrus.tasks.yml | ||
.cirrus.yml | ||
.dir-locals.el | ||
.editorconfig | ||
.git-blame-ignore-revs | ||
.gitattributes | ||
.gitignore | ||
aclocal.m4 | ||
configure | ||
configure.ac | ||
COPYRIGHT | ||
GNUmakefile.in | ||
HISTORY | ||
Makefile | ||
meson_options.txt | ||
meson.build | ||
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.
Copyright and license information can be found in the file COPYRIGHT.
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/.