Tom Lane wrote:
> Gregory Stark <stark@enterprisedb.com> writes:
>> So has anyone here done any experiments with live systems with different block
>> sizes? What were your experiences?
Mark tested this back in the OSDL days. His findings on DBT2 was that
the right *combination* of OS and PG blocksizes gave up to a 5%
performance increase, I think. Hardly enough to make it worth the
headache of running with non-default PG and non-deafault Linux block
sizes, especially since the wrong combination resulted in a decrease in
performance, sometimes dramatically so.
However, at Greenplum I remember determining that larger PG block sizes,
if matched with larger filesystem block sizes did significantly help on
performance of data warehouses which do a lot of seq scans -- but that
our ceiling of 32K was still too small to really make this work. I
don't have the figures for that, though; Luke reading this?
--Josh