Previously if a directory had both isolationtester and plain
regression tests, they couldn't be run in parallel, because they'd
access the same files/directories. That, so far, only affected
contrib/test_decoding.
Rather than fix that locally in contrib/test_decoding, improve
pg_regress_isolation_[install]check to use separate resources from
plain regression tests.
That requires a minor change in pg_regress, namely that the
--outputdir is created if not already existing, that seems like good
idea anyway.
Use the improved helpers even where previously not used.
Author: Tom Lane and Andres Freund
Discussion: https://postgr.es/m/20170311194831.vm5ikpczq52c2drg@alap3.anarazel.de
This feature, building on previous commits, allows the write-ahead log
stream to be decoded into a series of logical changes; that is,
inserts, updates, and deletes and the transactions which contain them.
It is capable of handling decoding even across changes to the schema
of the effected tables. The output format is controlled by a
so-called "output plugin"; an example is included. To make use of
this in a real replication system, the output plugin will need to be
modified to produce output in the format appropriate to that system,
and to perform filtering.
Currently, information can be extracted from the logical decoding
system only via SQL; future commits will add the ability to stream
changes via walsender.
Andres Freund, with review and other contributions from many other
people, including Álvaro Herrera, Abhijit Menon-Sen, Peter Gheogegan,
Kevin Grittner, Robert Haas, Heikki Linnakangas, Fujii Masao, Abhijit
Menon-Sen, Michael Paquier, Simon Riggs, Craig Ringer, and Steve
Singer.
Andres Freund
Robert Haas