e5836f7b7d
Use fake LSNs in all hash AM critical sections that write a WAL record. This gives us a reliable way (a way that works during scans of both logged and unlogged relations) to detect when an index page was concurrently modified during the window between when the page is initially read (by _hash_readpage) and when the page has any known-dead items LP_DEAD-marked (by _hash_kill_items). Preparation for an upcoming patch that makes the hash index AM use the amgetbatch interface, enabling I/O prefetching during hash index scans. The amgetbatch design imposes certain rules on index AMs with respect to how they hold on to index page buffer pins (at least in the case of pins held as an interlock against unsafe concurrent TID recycling by VACUUM). These rules have consequences for routines that set LP_DEAD bits on index tuples from an amgetbatch index AM: such routines have an inherent need to reason about concurrent TID recycling by VACUUM, but can no longer rely on their amgettuple routine holding on to a buffer pin (during the aforementioned window) as an interlock against such recycling. Instead, they have to follow a new, standardized approach. The new approach taken by amgetbatch index AMs when setting LP_DEAD bits is heavily based on the current nbtree dropPin design, which was added by commit |
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| config | ||
| contrib | ||
| doc | ||
| src | ||
| .cirrus.star | ||
| .cirrus.tasks.yml | ||
| .cirrus.yml | ||
| .dir-locals.el | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| aclocal.m4 | ||
| configure | ||
| configure.ac | ||
| COPYRIGHT | ||
| GNUmakefile.in | ||
| HISTORY | ||
| Makefile | ||
| meson.build | ||
| meson_options.txt | ||
| README.md | ||
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.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.