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The content of the patch is as follows: (1)Create shortcut when subtext was not found. (2)Stop using LEFT and RIGHT macro. In LEFT and RIGHT macro, TEXTPOS is executed by the same content as execution immediately before. The execution frequency of TEXTPOS can be reduced by using text_substring instead of LEFT and RIGHT macro. (3)Add appendStringInfoText, and use it instead of appendStringInfoString. There is an overhead of PG_TEXT_GET_STR when appendStringInfoString is executed by text type. This can be reduced by appendStringInfoText. (4)Reduce execution of TEXTDUP. The effect of the patch that I measured is as follows: - The Data for test was created by 'pgbench -i'. - Test SQL: select replace(aid, '9', 'A') from accounts; - Test results: Linux(CPU: Pentium III, Compiler option: -O2) original: 1.515s patched: 1.250s Atsushi Ogawa |
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contrib | ||
doc | ||
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aclocal.m4 | ||
configure | ||
configure.in | ||
COPYRIGHT | ||
GNUmakefile.in | ||
Makefile | ||
README | ||
README.CVS |
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. The JDBC, ODBC, C++, Python, and Tcl interfaces have been moved to the PostgreSQL Projects Web Site at http://gborg.postgresql.org for separate maintenance. A Perl DBI/DBD driver is available from CPAN. 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 ftp://ftp.postgresql.org/pub/. For more information look at our web site located at http://www.postgresql.org/.