Robert Haas <robertmhaas@gmail.com> writes:
> On Mon, Jan 7, 2013 at 11:16 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Why would that be a good tradeoff to make? Larger stored values require
>> more I/O, which is likely to swamp any CPU savings in the compression
>> step. Not to mention that a value once written may be read many times,
>> so the extra I/O cost could be multiplied many times over later on.
> I agree with this analysis, but I note that the test results show it
> actually improving things along both parameters.
Hm ... one of us is reading those results backwards, then.
regards, tom lane