dcfff74fb1
Reverts 27838981be9d (some comments are kept). Per discussion, it does not seem safe to relax the lock level used for this; in order for it to be safe, there would have to be memory barriers between the point we set the flag and the point we set the trasaction Xid, which perhaps would not be so bad; but there would also have to be barriers at the readers' side, which from a performance perspective might be bad. Now maybe this analysis is wrong and it *is* safe for some reason, but proof of that is not trivial. Discussion: https://postgr.es/m/20201118190928.vnztes7c2sldu43a@alap3.anarazel.de
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/.