ab359624b4
Since Postgres 10, SHOW commands can be triggered with replication connections in a WAL sender context, however it missed that a transaction context is needed for syscache lookups. This commit makes sure that the syscache lookups can happen correctly by setting a transaction context when running SHOW commands in a WAL sender. Superuser-only parameters can be displayed using SHOW commands not only to superusers, but also to members of system role pg_read_all_settings, which requires a syscache lookup to check if the connected role is a member of this system role or not, or the instance crashes. Superusers do not need to check the syscache so it worked correctly in this case. New tests are added to cover this issue. Reported-by: Alexander Kukushkin Author: Michael Paquier Reviewed-by: Álvaro Herrera Discussion: https://postgr.es/m/15734-2daa8761eeed8e20@postgresql.org Backpatch-through: 10
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/.