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random number seed each time. This is how it used to work years ago, but we got rid of the seed reset because it was resetting the main random() sequence and thus having undesirable effects on the rest of the system. To fix, establish a private random number state for each execution of geqo(), and initialize the state using the new GUC variable geqo_seed. People who want to experiment with different random searches can do so by changing geqo_seed, but you'll always get the same plan for the same value of geqo_seed (if holding all other planner inputs constant, of course). The new state is kept in PlannerInfo by adding a "void *" field reserved for use by join_search hooks. Most of the rather bulky code changes in this commit are just arranging to pass PlannerInfo around to all the GEQO functions (many of which formerly didn't receive it). Andres Freund, with some editorialization by Tom
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: http://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. 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 http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.