On Thu, 2010-07-29 at 19:08 +0200, Vincenzo Romano wrote: > Hi all. > I'm wondering about PGSQL scalability. > In particular I have two main topics in my mind: > > 1. What'd be the behavior of the query planner in the case I have > a single huge table with hundreds or thousands of partial indexes > (just differing by the WHERE clause). > This is an idea of mine to make index-partitioning instead of > table-partitioning.
Well the planner is not going to care about the partial indexes that don't match the where clause but what you are suggesting is going to make writes and maintenance extremely expensive. It will also increase planning time as the optimizer at a minimum has to discard the use of those indexes. > > 2. What'd be the behavior of the query planner in the case I have > hundreds or thousands of child tables, possibly in a multilevel hierarchy > (let's say, partitioning by year, month and company). Again, test it. Generally speaking the number of child tables directly correlates to planning time. Most experience that 60-100 tables is really the highest you can go. It all depends on actual implementation and business requirements however. Sincerely, Joshua D. Drake -- PostgreSQL.org Major Contributor Command Prompt, Inc: http://www.commandprompt.com/ - 509.416.6579 Consulting, Training, Support, Custom Development, Engineering http://twitter.com/cmdpromptinc | http://identi.ca/commandprompt -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
