postgresql/doc
Tom Lane b6423e92ab Doc: fix ancient mistake, or at least obsolete info, in rules example.
The example of expansion of multiple views claimed that the resulting
subquery nest would not get fully flattened because of an aggregate
function.  There's no aggregate in the example, though, only a user
defined function confusingly named MIN().  In a modern server, the
reason for the non-flattening is that MIN() is volatile, but I'm
unsure whether that was true back when this text was written.

Let's reduce the confusion level by using LEAST() instead (which
we didn't have at the time this example was created).  And then
we can just say that the planner will flatten the sub-queries, so
the rewrite system doesn't have to.

Noted by Paul Jungwirth.  This text is old enough to vote, so
back-patch to all supported branches.

Discussion: https://postgr.es/m/CA+renyXZFnmp9PcvX1EVR2dR=XG5e6E-AELr8AHCNZ8RYrpnPw@mail.gmail.com
2019-11-11 14:39:54 -05:00
..
src Doc: fix ancient mistake, or at least obsolete info, in rules example. 2019-11-11 14:39:54 -05:00
KNOWN_BUGS Remove extra newlines at end and beginning of files, add missing newlines 2010-08-19 05:57:36 +00:00
MISSING_FEATURES Remove extra newlines at end and beginning of files, add missing newlines 2010-08-19 05:57:36 +00:00
Makefile Remove maintainer-check target, fold into normal build 2013-10-10 20:11:56 -04:00
TODO Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00