174877f1e3
The previous method for doing that was to write zeroes into a predetermined set of page locations. However, there's a roughly 1-in-64K chance that the existing checksum will match by chance, and yesterday several buildfarm animals started to reproducibly see that, resulting in test failures because no checksum mismatch was reported. Since the checksum includes the page LSN, test success depends on the length of the installation's WAL history, which is affected by (at least) the initial catalog contents, the set of locales installed on the system, and the length of the pathname of the test directory. Sooner or later we were going to hit a chance match, and today is that day. Harden these tests by specifically inverting the checksum field and leaving all else alone, thereby guaranteeing that the checksum is incorrect. In passing, fix places that were using seek() to set up for syswrite(), a combination that the Perl docs very explicitly warn against. We've probably escaped problems because no regular buffered I/O is done on these filehandles; but if it ever breaks, we wouldn't deserve or get much sympathy. Although we've only seen problems in HEAD, now that we recognize the environmental dependencies it seems like it might be just a matter of time until someone manages to hit this in back-branch testing. Hence, back-patch to v11 where we started doing this kind of test. Discussion: https://postgr.es/m/3192026.1648185780@sss.pgh.pa.us |
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| contrib | ||
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| src | ||
| .cirrus.yml | ||
| .dir-locals.el | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| aclocal.m4 | ||
| configure | ||
| configure.ac | ||
| COPYRIGHT | ||
| GNUmakefile.in | ||
| HISTORY | ||
| Makefile | ||
| README | ||
| README.git | ||
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. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.