"Joshua D. Drake" <jd(at)commandprompt(dot)com> writes:
> Tom Lane wrote:
>> The aggregation is a great deal worse as well. I suspect that for some
>> reason the comparison operations involved in the sorting and grouping
>> are much slower on the FC3 machine. What are the data types of the
>> leading sort keys ...
>>
> Data types are:
> post_id integer
> topic_id integer
> topic_title character(255) (I have no idea why ;))
> forum_status and forum_id are smallints...
> The rest are pretty basic integers.
Hm. What is the data like --- in particular, are the topic_ids unique
in the data processed by the sort? I'm wondering how often the
sort/group comparisons would even look at columns beyond the first
two ...
regards, tom lane