47fe4d25d5
I broke this with my WAL format refactoring patch. Before that, the metapage was read from disk, and modified in-place regardless of the LSN. That was always a bit silly, as there's no need to read the old page version from disk disk when we're overwriting it anyway. So that was changed in 9.5, but I failed to add a GinInitPage call to initialize the page-headers correctly. Usually you wouldn't notice, because the metapage is already in the page cache and is not zeroed. One way to reproduce this is to perform a VACUUM on an already vacuumed table (so that the vacuum has no real work to do), immediately after a checkpoint, and then perform an immediate shutdown. After recovery, the page headers of the metapage will be incorrectly all-zeroes. Reported by Jeff Janes
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. 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/.