Thom Brown <thom@linux.com> writes:
> I've asked this question on IRC, but unfortunately no answer. Could
> someone tell me what system catalog changes were made between 9.0
> beta4 and RC1?
The CVS (or soon to be git) log for catversion.h is a good place to
look for answers to such questions.
http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h
In this case the answer is:
Remove the single-argument form of string_agg(). It added nothing much in
functionality, while creating an ambiguity in usage with ORDER BY that at
least two people have already gotten seriously confused by. Also, add an
opr_sanity test to check that we don't in future violate the newly minted
policy of not having built-in aggregates with the same name and different
numbers of parameters. Per discussion of a complaint from Thom Brown.
regards, tom lane