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033eb1581b
pg_listener modifications commanded by LISTEN and UNLISTEN until the end of the current transaction. This allows us to hold the ExclusiveLock on pg_listener until after commit, with no greater risk of deadlock than there was before. Aside from fixing the race condition, this gets rid of a truly ugly kludge that was there before, namely having to ignore HeapTupleBeingUpdated failures during NOTIFY. There is a small potential incompatibility, which is that if a transaction issues LISTEN or UNLISTEN and then looks into pg_listener before committing, it won't see any resulting row insertion or deletion, where before it would have. It seems unlikely that anyone would be depending on that, though. This patch also disallows LISTEN and UNLISTEN inside a prepared transaction. That case had some pretty undesirable properties already, such as possibly allowing pg_listener entries to be made for PIDs no longer present, so disallowing it seems like a better idea than trying to maintain the behavior. |
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| contrib | ||
| doc | ||
| src | ||
| 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. 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 binding 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/.