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place to prevent reusing relation OIDs before next checkpoint, and DROP DATABASE. First, if a database was dropped, bgwriter would still try to unlink the files that the rmtree() call by the DROP DATABASE command has already deleted, or is just about to delete. Second, if a database is dropped, and another database is created with the same OID, bgwriter would in the worst case delete a relation in the new database that happened to get the same OID as a dropped relation in the old database. To fix these race conditions: - make rmtree() ignore ENOENT errors. This fixes the 1st race condition. - make ForgetDatabaseFsyncRequests forget unlink requests as well. - force checkpoint on in dropdb on all platforms Since ForgetDatabaseFsyncRequests() is asynchronous, the 2nd change isn't enough on its own to fix the problem of dropping and creating a database with same OID, but forcing a checkpoint on DROP DATABASE makes it sufficient. Per Tom Lane's bug report and proposal. Backpatch to 8.3.
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 including some of the more common listed below: C++ - http://pqxx.org/development/libpqxx/ JDBC - http://jdbc.postgresql.org ODBC - http://odbc.postgresql.org Perl - http://search.cpan.org/~dbdpg/ PHP - http://www.php.net Python - http://www.initd.org/ Ruby - http://ruby.scripting.ca/postgres/ Other language bindings are available from a variety of contributing parties. PostgreSQL also has a great number of procedural languages available, a short, incomplete list is below: PL/pgSQL - included in PostgreSQL source distribution PL/Perl - included in PostgreSQL source distribution PL/PHP - http://projects.commandprompt.com/projects/public/plphp PL/Python - included in PostgreSQL source distribution PL/Java - http://pgfoundry.org/projects/pljava/ PL/Tcl - included in PostgreSQL source distribution 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/.