93d888232e
contains newly-inserted tuples that according to our OldestXmin are not yet visible to everyone. The value returned by GetOldestXmin() is conservative, and it can move backwards on repeated calls, so if we see that contradiction between the PD_ALL_VISIBLE flag and status of tuples on the page, we have to assume it's because an earlier vacuum calculated a higher OldestXmin value, and all the tuples really are visible to everyone. We have received several reports of this bug, with the "PD_ALL_VISIBLE flag was incorrectly set in relation ..." warning appearing in logs. We were finally able to hunt it down with David Gould's help to run extra diagnostics in an environment where this happened frequently. Also reword the warning, per Robert Haas' suggestion, to not imply that the PD_ALL_VISIBLE flag is necessarily at fault, as it might also be a symptom of corruption on a tuple header. Backpatch to 8.4, where the PD_ALL_VISIBLE flag was introduced.
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, many of which are listed here: http://www.postgresql.org/download 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/.