e0b1ee17dc
Currently, B-tree code matches every scan key to every item on the page. Imagine the ordered B-tree scan for the query like this. SELECT * FROM tbl WHERE col > 'a' AND col < 'b' ORDER BY col; The (col > 'a') scan key will be always matched once we find the location to start the scan. The (col < 'b') scan key will match every item on the page as long as it matches the last item on the page. This patch implements prechecking of the scan keys required for directional scan on beginning of page scan. If precheck is successful we can skip this scan keys check for the items on the page. That could lead to significant acceleration especially if the comparison operator is expensive. Idea from patch by Konstantin Knizhnik. Discussion: https://postgr.es/m/079c3f8e-3371-abe2-e93c-fc8a0ae3f571%40garret.ru Reviewed-by: Peter Geoghegan, Pavel Borisov |
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| contrib | ||
| doc | ||
| src | ||
| .cirrus.star | ||
| .cirrus.tasks.yml | ||
| .cirrus.yml | ||
| .dir-locals.el | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
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| COPYRIGHT | ||
| GNUmakefile.in | ||
| HISTORY | ||
| Makefile | ||
| README | ||
| README.git | ||
| aclocal.m4 | ||
| configure | ||
| configure.ac | ||
| meson.build | ||
| meson_options.txt | ||
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: 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/.