postgres

Commit Graph

Author	SHA1	Message	Date
Tomas Vondra	ba2a3c2302	Add pg_buffercache_numa view with NUMA node info Introduces a new view pg_buffercache_numa, showing NUMA memory nodes for individual buffers. For each buffer the view returns an entry for each memory page, with the associated NUMA node. The database blocks and OS memory pages may have different size - the default block size is 8KB, while the memory page is 4K (on x86). But other combinations are possible, depending on configure parameters, platform, etc. This means buffers may overlap with multiple memory pages, each associated with a different NUMA node. To determine the NUMA node for a buffer, we first need to touch the memory pages using pg_numa_touch_mem_if_required, otherwise we might get status -2 (ENOENT = The page is not present), indicating the page is either unmapped or unallocated. The view may be relatively expensive, especially when accessed for the first time in a backend, as it touches all memory pages to get reliable information about the NUMA node. This may also force allocation of the shared memory. Author: Jakub Wartak <jakub.wartak@enterprisedb.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> Reviewed-by: Tomas Vondra <tomas@vondra.me> Discussion: https://postgr.es/m/CAKZiRmxh6KWo0aqRqvmcoaX2jUxZYb4kGp3N%3Dq1w%2BDiH-696Xw%40mail.gmail.com	5 months ago
Thomas Munro	13453eedd3	Add pg_buffercache_evict() function for testing. When testing buffer pool logic, it is useful to be able to evict arbitrary blocks. This function can be used in SQL queries over the pg_buffercache view to set up a wide range of buffer pool states. Of course, buffer mappings might change concurrently so you might evict a block other than the one you had in mind, and another session might bring it back in at any time. That's OK for the intended purpose of setting up developer testing scenarios, and more complicated interlocking schemes to give stronger guararantees about that would likely be less flexible for actual testing work anyway. Superuser-only. Author: Palak Chaturvedi <chaturvedipalak1911@gmail.com> Author: Thomas Munro <thomas.munro@gmail.com> (docs, small tweaks) Reviewed-by: Nitin Jadhav <nitinjadhavpostgres@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Cary Huang <cary.huang@highgo.ca> Reviewed-by: Cédric Villemain <cedric.villemain+pgsql@abcsql.com> Reviewed-by: Jim Nasby <jim.nasby@gmail.com> Reviewed-by: Maxim Orlov <orlovmg@gmail.com> Reviewed-by: Thomas Munro <thomas.munro@gmail.com> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Discussion: https://postgr.es/m/CALfch19pW48ZwWzUoRSpsaV9hqt0UPyaBPC4bOZ4W+c7FF566A@mail.gmail.com	1 year ago
Andres Freund	2589434ae0	pg_buffercache: Add pg_buffercache_summary() Using pg_buffercache_summary() is significantly cheaper than querying pg_buffercache and summarizing in SQL. Author: Melih Mutlu <m.melihmutlu@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Aleksander Alekseev <aleksander@timescale.com> Reviewed-by: Zhang Mingli <zmlpostgres@gmail.com> Discussion: https://postgr.es/m/CAGPVpCQAXYo54Q%3D8gqBsS%3Du0uk9qhnnq4%2B710BtUhUisX1XGEg%40mail.gmail.com	3 years ago
Robert Haas	a448e49bcb	Revert 56-bit relfilenode change and follow-up commits. There are still some alignment-related failures in the buildfarm, which might or might not be able to be fixed quickly, but I've also just realized that it increased the size of many WAL records by 4 bytes because a block reference contains a RelFileLocator. The effect of that hasn't been studied or discussed, so revert for now.	3 years ago
Robert Haas	05d4cbf9b6	Increase width of RelFileNumbers from 32 bits to 56 bits. RelFileNumbers are now assigned using a separate counter, instead of being assigned from the OID counter. This counter never wraps around: if all 2^56 possible RelFileNumbers are used, an internal error occurs. As the cluster is limited to 2^64 total bytes of WAL, this limitation should not cause a problem in practice. If the counter were 64 bits wide rather than 56 bits wide, we would need to increase the width of the BufferTag, which might adversely impact buffer lookup performance. Also, this lets us use bigint for pg_class.relfilenode and other places where these values are exposed at the SQL level without worrying about overflow. This should remove the need to keep "tombstone" files around until the next checkpoint when relations are removed. We do that to keep RelFileNumbers from being recycled, but now that won't happen anyway. However, this patch doesn't actually change anything in this area; it just makes it possible for a future patch to do so. Dilip Kumar, based on an idea from Andres Freund, who also reviewed some earlier versions of the patch. Further review and some wordsmithing by me. Also reviewed at various points by Ashutosh Sharma, Vignesh C, Amul Sul, Álvaro Herrera, and Tom Lane. Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com	3 years ago
Simon Riggs	25fff40798	Default monitoring roles Three nologin roles with non-overlapping privs are created by default * pg_read_all_settings - read all GUCs. * pg_read_all_stats - pg_stat_, pg_database_size(), pg_tablespace_size() pg_stat_scan_tables - may lock/scan tables Top level role - pg_monitor includes all of the above by default, plus others Author: Dave Page Reviewed-by: Stephen Frost, Robert Haas, Peter Eisentraut, Simon Riggs	9 years ago
Robert Haas	06d7fd6e29	Update pg_buffercache extension for parallel query. The pg_buffercache_pages function provided by this extension is PARALLEL SAFE. Andreas Karlsson	9 years ago
Andres Freund	f57791985a	Add pinning_backends column to the pg_buffercache extension. The new column shows how many backends have a buffer pinned. That can be useful during development or to diagnose production issues e.g. caused by vacuum waiting for cleanup locks. To handle upgrades transparently - the extension might be used in views - deal with callers expecting the old number of columns. Reviewed by Fujii Masao and Rajeev rastogi.	11 years ago
Tom Lane	629b3af27d	Convert contrib modules to use the extension facility. This isn't fully tested as yet, in particular I'm not sure that the "foo--unpackaged--1.0.sql" scripts are OK. But it's time to get some buildfarm cycles on it. sepgsql is not converted to an extension, mainly because it seems to require a very nonstandard installation process. Dimitri Fontaine and Tom Lane	15 years ago

9 Commits (master)