c89a0dd3bb
to try to create a log segment file concurrently, but the code erroneously specified O_EXCL to open(), resulting in a needless failure. Before 7.4, it was even a PANIC condition :-(. Correct code is actually simpler than what we had, because we can just say O_CREAT to start with and not need a second open() call. I believe this accounts for several recent reports of hard-to-reproduce "could not create file ...: File exists" errors in both pg_clog and pg_subtrans.
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. The JDBC, ODBC, C++, Python, and Tcl 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/.