postgresql/src/bin/pg_amcheck
Andres Freund c66a7d75e6 Handle DROP DATABASE getting interrupted
Until now, when DROP DATABASE got interrupted in the wrong moment, the removal
of the pg_database row would also roll back, even though some irreversible
steps have already been taken. E.g. DropDatabaseBuffers() might have thrown
out dirty buffers, or files could have been unlinked. But we continued to
allow connections to such a corrupted database.

To fix this, mark databases invalid with an in-place update, just before
starting to perform irreversible steps. As we can't add a new column in the
back branches, we use pg_database.datconnlimit = -2 for this purpose.

An invalid database cannot be connected to anymore, but can still be
dropped.

Unfortunately we can't easily add output to psql's \l to indicate that some
database is invalid, it doesn't fit in any of the existing columns.

Add tests verifying that a interrupted DROP DATABASE is handled correctly in
the backend and in various tools.

Reported-by: Evgeny Morozov <postgresql3@realityexists.net>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/20230509004637.cgvmfwrbht7xm7p6@awork3.anarazel.de
Discussion: https://postgr.es/m/20230314174521.74jl6ffqsee5mtug@awork3.anarazel.de
Backpatch: 11-, bug present in all supported versions
2023-07-13 13:03:28 -07:00
..
po Translation updates 2023-05-22 12:44:31 +02:00
t Handle DROP DATABASE getting interrupted 2023-07-13 13:03:28 -07:00
.gitignore
Makefile Update copyright for 2023 2023-01-02 15:00:37 -05:00
README Doc: improve README files associated with TAP tests. 2021-10-31 18:12:44 -04:00
meson.build Update copyright for 2023 2023-01-02 15:00:37 -05:00
nls.mk Revert "Use wildcards instead of manually-maintained file lists in */nls.mk." 2022-07-13 14:29:10 -04:00
pg_amcheck.c Handle DROP DATABASE getting interrupted 2023-07-13 13:03:28 -07:00

README

src/bin/pg_amcheck/README

pg_amcheck is a command-line tool for running the amcheck extension.

Running the regression tests
============================

NOTE: You must have given the --enable-tap-tests argument to configure.
Also, to use "make installcheck", you must have built and installed
contrib/amcheck and contrib/pageinspect in addition to the core code.

Run
    make check
or
    make installcheck
You can use "make installcheck" if you previously did "make install".
In that case, the code in the installation tree is tested.  With
"make check", a temporary installation tree is built from the current
sources and then tested.

See src/test/perl/README for more info about running these tests.