29ef1dd19b
When an UPDATE or DELETE action in MERGE returns TM_SelfModified,
there are 2 possible causes:
1). The target tuple was already updated or deleted by the current
command. This can happen if the target row joins to more than one
source row, and the SQL standard explicitly says that this must be
an error.
2). The target tuple was already updated or deleted by a later command
in the current transaction. This can happen if the tuple is
modified by a BEFORE trigger or a volatile function used in the
query, and should be an error for the same reason that it is in a
plain UPDATE or DELETE command.
In MERGE's primary error handling block, it failed to check for (2),
causing it to return a misleading error message in such cases.
In the secondary error handling block, following a concurrent update
from another session, it failed to check for (1), causing it to
silently ignore target rows joined to more than one source row,
instead of reporting an error.
Fix this, and add tests for both of these cases.
Per report from Wenjiang Zhang. Back-patch to v15, where MERGE was
introduced.
Discussion: https://postgr.es/m/tencent_41DE0FF443FE14B94A5898D373792109E408%40qq.com
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| doc | ||
| src | ||
| .cirrus.star | ||
| .cirrus.tasks.yml | ||
| .cirrus.yml | ||
| .dir-locals.el | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| aclocal.m4 | ||
| configure | ||
| configure.ac | ||
| COPYRIGHT | ||
| GNUmakefile.in | ||
| HISTORY | ||
| Makefile | ||
| meson_options.txt | ||
| meson.build | ||
| 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/.