postgresql/src/backend/utils
Tomas Vondra 13380e1476 Don't print extra parens around expressions in extended stats
The code printing expressions for extended statistics doubled the
parens, producing results like ((a+1)), which is unnecessary and not
consistent with how we print expressions elsewhere.

Fixed by tweaking the code to produce just a single set of parens.

Reported by Mark Dilger, fix by me. Backpatch to 14, where support for
extended statistics on expressions was added.

Reported-by: Mark Dilger
Discussion: https://postgr.es/m/20210122040101.GF27167%40telsasoft.com
2021-09-01 00:43:22 +02:00
..
activity Unset MyBEEntry, making elog.c's call to pgstat_get_my_query_id() safe. 2021-08-19 05:07:53 -07:00
adt Don't print extra parens around expressions in extended stats 2021-09-01 00:43:22 +02:00
cache Reduce memory consumption for pending invalidation messages. 2021-08-16 16:48:25 -04:00
error Initial pgindent and pgperltidy run for v14. 2021-05-12 13:14:10 -04:00
fmgr Reconsider the handling of procedure OUT parameters. 2021-06-10 17:11:36 -04:00
hash Update copyright for 2021 2021-01-02 13:06:25 -05:00
init Fix typo. 2021-08-13 05:44:03 -07:00
mb Fix typo in comment 2021-07-22 09:37:35 +02:00
misc Improve defaults shown in postgresql.conf.sample and pg_settings 2021-08-23 12:33:38 -04:00
mmgr Restore the portal-level snapshot after procedure COMMIT/ROLLBACK. 2021-05-21 14:03:59 -04:00
resowner Refactor HMAC implementations 2021-04-03 17:30:49 +09:00
sort Refactor sharedfileset.c to separate out fileset implementation. 2021-08-30 08:48:15 +05:30
time Initial pgindent and pgperltidy run for v14. 2021-05-12 13:14:10 -04:00
.gitignore Rearrange makefile rules for running Gen_fmgrtab.pl. 2018-05-03 17:54:18 -04:00
errcodes.txt Rethink SQLSTATE code for ERRCODE_IDLE_SESSION_TIMEOUT. 2021-01-11 14:53:42 -05:00
Gen_dummy_probes.pl Emit dummy statements for probes.d probes when disabled 2021-05-10 11:40:03 +02:00
Gen_dummy_probes.pl.prolog Tweak generation of Gen_dummy_probes.pl 2021-05-11 20:02:02 -04:00
Gen_dummy_probes.sed Emit dummy statements for probes.d probes when disabled 2021-05-10 11:40:03 +02:00
Gen_fmgrtab.pl Update copyright for 2021 2021-01-02 13:06:25 -05:00
generate-errcodes.pl Update copyright for 2021 2021-01-02 13:06:25 -05:00
Makefile Tweak generation of Gen_dummy_probes.pl 2021-05-11 20:02:02 -04:00
probes.d Update copyright for 2021 2021-01-02 13:06:25 -05:00
README.Gen_dummy_probes Tweak generation of Gen_dummy_probes.pl 2021-05-11 20:02:02 -04:00

# Generating dummy probes

If Postgres isn't configured with dtrace enabled, we need to generate
dummy probes for the entries in probes.d, that do nothing.

This is accomplished in Unix via the sed script `Gen_dummy_probes.sed`. We
used to use this in MSVC builds using the perl utility `psed`, which mimicked
sed. However, that utility disappeared from Windows perl distributions and so
we converted the sed script to a perl script to be used in MSVC builds.

We still keep the sed script as the authoritative source for generating
these dummy probes because except on Windows perl is not a hard requirement
when building from a tarball.

So, if you need to change the way dummy probes are generated, first change
the sed script, and when it's working generate the perl script. This can
be accomplished by using the perl utility s2p.

s2p is no longer part of the perl core, so it might not be on your system,
but it is available on CPAN and also in many package systems. e.g.
on Fedora it can be installed using `cpan App::s2p` or
`dnf install perl-App-s2p`.

The Makefile contains a recipe for regenerating Gen_dummy_probes.pl, so all
you need to do is once you have s2p installed is `make Gen_dummy_probes.pl`
Note that in a VPATH build this will generate the file in the vpath tree,
not the source tree.