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mirror of https://github.com/postgres/postgres.git synced 2025-05-01 01:04:50 +03:00
Dean Rasheed ca481d3c9a Optimise numeric multiplication for short inputs.
When either input has a small number of digits, and the exact product
is requested, the speed of numeric multiplication can be increased
significantly by using a faster direct multiplication algorithm. This
works by fully computing each result digit in turn, starting with the
least significant, and propagating the carry up. This save cycles by
not requiring a temporary buffer to store digit products, not making
multiple passes over the digits of the longer input, and not requiring
separate carry-propagation passes.

For now, this is used when the shorter input has 1-4 NBASE digits (up
to 13-16 decimal digits), and the longer input is of any size, which
covers a lot of common real-world cases. Also, the relative benefit
increases as the size of the longer input increases.

Possible future work would be to try extending the technique to larger
numbers of digits in the shorter input.

Joel Jacobson and Dean Rasheed.

Discussion: https://postgr.es/m/44d2ffca-d560-4919-b85a-4d07060946aa@app.fastmail.com
2024-07-09 10:00:42 +01:00
2019-12-18 09:13:13 +01:00
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2020-02-10 20:47:50 +01:00
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2024-07-01 07:56:10 +09:00

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.

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/.

Description
Зеркало официального репозитория PostgreSQL GIT
Readme 1.1 GiB
Languages
C 85.3%
PLpgSQL 6%
Perl 4.4%
Yacc 1.2%
Meson 0.7%
Other 2.1%