a7e8ece41c
pg_rewind needs to copy from the source cluster to the target cluster a set of relation blocks changed from the previous checkpoint where WAL forked up to the end of WAL on the target. Building this list of relation blocks requires a range of WAL segments that may not be present anymore on the target's pg_wal, causing pg_rewind to fail. It is possible to work around this issue by copying manually the WAL segments needed but this may lead to some extra and actually useless work. This commit introduces a new option allowing pg_rewind to use a restore_command while doing the rewind by grabbing the parameter value of restore_command from the target cluster configuration. This allows the rewind operation to be more reliable, so as only the WAL segments needed by the rewind are restored from the archives. In order to be able to do that, a new routine is added to src/common/ to allow frontend tools to restore files from archives using an already-built restore command. This version is more simple than the backend equivalent as there is no need to handle the non-recovery case. Author: Alexey Kondratov Reviewed-by: Andrey Borodin, Andres Freund, Alvaro Herrera, Alexander Korotkov, Michael Paquier Discussion: https://postgr.es/m/a3acff50-5a0d-9a2c-b3b2-ee36168955c1@postgrespro.ru
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: https://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 https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.