On Thu, Sep 2, 2010 at 10:45 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> 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.
Cool, so in this case Thom could have found the changes by grepping
for his own name in the source. :)
