27bdec0684
Improve performance and reduce table sizes for case mapping. The main case mapping table stores only 16-bit offsets, which can be used to look up the mapped code point in any of the case tables (fold, lower, upper, or title case). Simple case pairs point to the same offsets. Generate a function in generate-unicode_case_table.pl that consists of a nested branches to test for specific codepoint ranges that determine the offset in the main table. Other approaches were considered, such as representing these ranges as another structure (rather than branches in a generated function), or a different approach such as a radix tree, or perfect hashing. The author implemented and tested these alternatives and settled on the generated branches. Author: Alexander Borisov <lex.borisov@gmail.com> Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://postgr.es/m/7cac7e66-9a3b-4e3f-a997-42aa0c401f80%40gmail.com
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/.