On Fri, Mar 30, 2012 at 8:45 AM, Campbell, Lance
<lance@illinois.edu> wrote:
PostgreSQL 9.0.x
When PostgreSQL storage is using a relatively large raid 5 or 6 array is there any value in having your tables distributed across multiple tablespaces if those tablespaces will exists on the same raid array? I understand the value if you were to have the tablespaces on different raid arrays. But what about on the same one?
Our application is a combination of OLTP and OLAP. We've successfully split the database into 3 different tablespaces.
1. RAID Group A is RAID 10 contains /var/lib/pgsql/data and the OLTP database (default tablespace)
2. RAID Group B is a RAID 10 for the indexes on the data warehouse (index tablespace)
3. RAID Group C is a RAID 5 containing the actual data warehouse (data tablespace)
A more optimum configuration would include another RAID 10 for the indexes for the OLTP but we ran out of drives to create a RAID Group D and the above configuration works well enough.
-Greg