mirror of
https://github.com/postgres/postgres.git
synced 2025-05-06 19:59:18 +03:00
When performing inlining LLVM unfortunately "leaks" types (the types survive and are usable, but a new round of inlining will recreate new structurally equivalent types). This accumulation will over time amount to a memory leak which for some queries can be large enough to trigger the OOM process killer. To avoid accumulation of types, all IR related data is stored in an LLVMContextRef which is dropped and recreated in order to release all types. Dropping and recreating incurs overhead, so it will be done only after 100 queries. This is a heuristic which might be revisited, but until we can get the size of the context from LLVM we are flying a bit blind. This issue has been reported several times, there may be more references to it in the archives on top of the threads linked below. This is a backpatch of 9dce22033d5 to all supported branches. Reported-By: Justin Pryzby <pryzby@telsasoft.com> Reported-By: Kurt Roeckx <kurt@roeckx.be> Reported-By: Jaime Casanova <jcasanov@systemguards.com.ec> Reported-By: Lauri Laanmets <pcspets@gmail.com> Author: Andres Freund and Daniel Gustafsson Discussion: https://postgr.es/m/7acc8678-df5f-4923-9cf6-e843131ae89d@www.fastmail.com Discussion: https://postgr.es/m/20201218235607.GC30237@telsasoft.com Discussion: https://postgr.es/m/CAPH-tTxLf44s3CvUUtQpkDr1D8Hxqc2NGDzGXS1ODsfiJ6WSqA@mail.gmail.com Backpatch-through: v12
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/.
Languages
C
85.3%
PLpgSQL
5.9%
Perl
4.4%
Yacc
1.2%
Meson
0.7%
Other
2.2%