e34082ee3b
better SQL compliance in this area, per recent discussion. Mark related operators as commutators where possible. (The system doesn't actually care about commutator marking for operators not returning boolean, at the moment, but this seems forward-thinking and besides it made it easier to verify that we hadn't missed any.) Also, remove interval-minus-time and interval-minus-timetz operators. I'm not sure how these got in, but they are nonstandard and had very obviously broken behavior. (minus is not commutative in anyone's book.) I doubt anyone had ever used 'em, because we'd surely have gotten a bug report about it if so.
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 several language bindings, including C and Tcl. The JDBC, ODBC, C++, and Python interfaces have been moved to the PostgreSQL Projects Web Site at http://gborg.postgresql.org for separate maintenance. A Perl DBI/DBD driver is available from CPAN. 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 ftp://ftp.postgresql.org/pub/. For more information look at our web site located at http://www.postgresql.org/.