mirror of
https://github.com/postgres/postgres.git
synced 2025-05-02 11:44:50 +03:00
fe35c0b6e5
If VirtualXactLock() has to wait for a transaction that holds its VXID lock as a fast-path lock, it must first convert the fast-path lock to a regular lock. It failed to take the required "partition" lock on the main shared-memory lock table while doing so. This is the direct cause of the assert failure in GetLockStatusData() recently observed in the buildfarm, but more worryingly it could result in arbitrary corruption of the shared lock table if some other process were concurrently engaged in modifying the same partition of the lock table. Fortunately, VirtualXactLock() is only used by CREATE INDEX CONCURRENTLY and DROP INDEX CONCURRENTLY, so the opportunities for failure are fewer than they might have been. In passing, improve some comments and be a bit more consistent about order of operations.
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/.