I declared all the indexes that you suggested and ran vacuum full
analyze. The query plan has not changed and it's still trying to use
seqscan. I tried to disable seqscan, but the plan didn't change. Any
other suggestions?
I started explain analyze on the query, but I doubt it will finish any
time soon.


-----Original Message-----
From: Josh Berkus [mailto:[EMAIL PROTECTED] 
Sent: Thursday, October 02, 2003 11:27 PM
To: Oleg Lebedev; scott.marlowe
Subject: Re: [PERFORM] TPC-R benchmarks


> I have another question. How do I optimize my indexes for the query 
> that contains a lot of ORed blocks, each of which contains a bunch of 
> ANDed expressions? The structure of each ORed block is the same except

> the right-hand-side values vary.

Given the example, I'd do a multicolumn index on p_brand, p_container,
and a second multicolumn index on l_partkey, l_quantity, l_shipmode.
... or maybe seperate indexes, one on l_partkey and one on l_quantity, 
l_shipmode & l_instruct.   Test both configurations.

Mind you, if this is also an OLTP table, then you'd want to test those 
multi-column indexes to determine the least columns you need for the
still to be used, since more columns = more index maintainence.

Josh Berkus
Aglio Database Solutions
San Francisco


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