8e684ce11d
Previously, if an unlogged sequence was created on the primary and
replicated to a standby, reading the sequence after promoting the
standby (for example, with nextval()) could trigger the following
assertion failure:
TRAP: failed Assert("((const PageHeaderData *) page)->pd_special >= SizeOfPageHeaderData")
In non-assert builds, the same operation could instead fail with an
error such as:
ERROR: bad magic number in sequence
The problem was that seq_redo() updated the init fork page in shared
buffers but did not flush it to disk. During promotion,
ResetUnloggedRelations() recreates the main fork of unlogged
relations by copying the init fork from disk, bypassing shared
buffers. As a result, the main fork could be recreated from a stale
init fork instead of the WAL-replayed page.
Fix this by introducing a helper to flush init fork buffers
immediately, and make seq_redo() use it. As a result, the main fork
of an unlogged sequence is recreated from the up-to-date init fork on
disk, allowing the unlogged sequence to be read successfully after
standby promotion.
Backpatch to v15, where unlogged sequences were introduced.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwH1Ssze3XM6wjoTjSLVOR041c6xP+vsdLP951=w8oG8bA@mail.gmail.com
Backpatch-through: 15
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| 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/.