7 Commits (master)

Author	SHA1	Message	Date
Michael Paquier	9ccc049dfe	pg_buffercache: Add pg_buffercache_mark_dirty{,_relation,_all}() ... This commit introduces three new functions for marking shared buffers as dirty by using the functions introduced in 9660906dbd69: * pg_buffercache_mark_dirty() for one shared buffer. - pg_buffercache_mark_dirt_relation() for all the shared buffers in a relation. * pg_buffercache_mark_dirty_all() for all the shared buffers in pool. The "_all" and "_relation" flavors are designed to address the inefficiency of repeatedly calling pg_buffercache_mark_dirty() for each individual buffer, which can be time-consuming when dealing with with large shared buffers pool. These functions are intended as developer tools and are available only to superusers. There is no need to bump the version of pg_buffercache, 4b203d499c having done this job in this release cycle. Author: Nazir Bilal Yavuz <byavuz81@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Aidar Imamov <a.imamov@postgrespro.ru> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com> Reviewed-by: Joseph Koshakow <koshy44@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Yuhang Qiu <iamqyh@gmail.com> Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com> Discussion: https://postgr.es/m/CAN55FZ0h_YoSqqutxV6DES1RW8ig6wcA8CR9rJk358YRMxZFmw@mail.gmail.com	1 month ago
Michael Paquier	4b203d499c	pg_buffercache: Add pg_buffercache_os_pages ... ba2a3c2302 has added a way to check if a buffer is spread across multiple pages with some NUMA information, via a new view pg_buffercache_numa that depends on pg_buffercache_numa_pages(), a SQL function. These can only be queried when support for libnuma exists, generating an error if not. However, it can be useful to know how shared buffers and OS pages map when NUMA is not supported or not available. This commit expands the capabilities around pg_buffercache_numa: - pg_buffercache_numa_pages() is refactored as an internal function, able to optionally process NUMA. Its SQL definition prior to this commit is still around to ensure backward-compatibility with v1.6. - A SQL function called pg_buffercache_os_pages() is added, able to work with or without NUMA. - The view pg_buffercache_numa is redefined to use pg_buffercache_os_pages(). - A new view is added, called pg_buffercache_os_pages. This ignores NUMA for its result processing, for a better efficiency. The implementation is done so as there is no code duplication between the NUMA and non-NUMA views/functions, relying on one internal function that does the job for all of them. The module is bumped to v1.7. Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> Reviewed-by: Mircea Cadariu <cadariu.mircea@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/Z/fFA2heH6lpSLlt@ip-10-97-1-34.eu-west-3.compute.internal	1 month ago
Andres Freund	dcf7e1697b	Add pg_buffercache_evict_{relation,all} functions ... In addition to the added functions, the pg_buffercache_evict() function now shows whether the buffer was flushed. pg_buffercache_evict_relation(): Evicts all shared buffers in a relation at once. pg_buffercache_evict_all(): Evicts all shared buffers at once. Both functions provide mechanism to evict multiple shared buffers at once. They are designed to address the inefficiency of repeatedly calling pg_buffercache_evict() for each individual buffer, which can be time-consuming when dealing with large shared buffer pools. (e.g., ~477ms vs. ~2576ms for 16GB of fully populated shared buffers). These functions are intended for developer testing and debugging purposes and are available to superusers only. Minimal tests for the new functions are included. Also, there was no test for pg_buffercache_evict(), test for this added too. No new extension version is needed, as it was already increased this release by ba2a3c2302. Author: Nazir Bilal Yavuz <byavuz81@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Aidar Imamov <a.imamov@postgrespro.ru> Reviewed-by: Joseph Koshakow <koshy44@gmail.com> Discussion: https://postgr.es/m/CAN55FZ0h_YoSqqutxV6DES1RW8ig6wcA8CR9rJk358YRMxZFmw%40mail.gmail.com	9 months ago
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	9 months ago
Tom Lane	f3fa31327e	Add pg_buffercache_usage_counts() to contrib/pg_buffercache. ... It was pointed out that pg_buffercache_summary()'s report of the overall average usage count isn't that useful, and what would be more helpful in many cases is to report totals for each possible usage count. Add a new function to do it like that. Since pg_buffercache 1.4 is already new for v16, we don't need to create a new extension version; we'll just define this as part of 1.4. Nathan Bossart Discussion: https://postgr.es/m/20230130233040.GA2800702@nathanxps13	3 years 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
Tom Lane	be39d88934	Add regression test coverage for contrib/pg_buffercache. ... We can't check the output of this view very closely without creating portability headaches, but we can make sure that the number of rows is as-expected. In any case, this is sufficient to exercise all the C code within, which is a lot better than the 0% coverage we had before. DongWook Lee Discussion: https://postgr.es/m/CAAcByaLCHGJB7qAENEcx9D09UL=w4ma+yijwF_-1MSqQZ9wK6Q@mail.gmail.com	3 years ago