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output is not of the same type that's needed for the IN comparison (ie, where the parser inserted an implicit coercion above the subselect result). We should record the coerced expression, not just a raw Var referencing the subselect output, as the quantity that needs to be unique-ified if we choose to implement the IN as Unique followed by a plain join. As of 8.3 this error was causing crashes, as seen in bug #4113 from Javier Hernandez, because the executor was being told to hash or sort the raw subselect output column using operators appropriate to the coerced type. In prior versions there was no crash because the executor chose the hash or sort operators for itself based on the column type it saw. However, that's still not really right, because what's unique for one data type might not be unique for another. In corner cases we could get multiple outputs of a row that should appear only once, as demonstrated by the regression test case included in this commit. However, this patch doesn't apply cleanly to 8.2 or before, and the code involved has shifted enough over time that I'm hesitant to try to back-patch. Given the lack of complaints from the field about such corner cases, I think the bug may not be important enough to risk breaking other things with a back-patch.
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/.