Re: Big table with UNION ALL or partitioning with Tsearch2

Joshua D. Drake wrote:
> Benjamin Arai wrote:
> RAID 5 with 16 spindles? RAID 10 will give you better performance I
> would think.

I'd say RAID 5 is not that bad for this kind of query, at least if the
controller is worth anything. RAID 10 is the best choice for OLTP, but
if the main job for this query is to read an index as fast as possible,
RAID 5 might be well suited. I have good experience with TSearch queries
on a 8 drive RAID 6 setup.

Even if those 16 drives are cheap desktop SATAs, he should be able to
read with around 800MB/sec.

Benjamin, could you try if the following does change your query
performance in any way?

blockdev --setra 16384 /dev/sdX


--
Best regards,
Hannes Dorbath