On Thu, May 18, 2006 at 12:38:18PM -0700, Stephen Byers wrote:
> I repeated explain analyze on the query 5 times and it came up with the same
> plan.
>
> You asked about index order and physical table order. In general the index
> order is indeed close to the same order as the physical table order.
> However, this query is likely an exception. The data is actually from a
> backup server that has filled a hole for some of the time range that I'm
> specifying in my query.
What's SELECT correlation FROM pg_stats WHERE tablename='packets' AND
attname='environment_name' show?
What's effective_cache_size and random_page_cost set to?
Also, out of curiosity, why not just use a timestamp instead of two
int's for storing time?
> Wow -- so what does that mean? Do I need to leave my work_mem at 100MB??
> I mentioned that my application actually uses a cursor to walk through this
> data. Even though the bitmap scan technically had the fastest time with
> explain analyze, it takes a long while (20 seconds) before the results start
> to come back through the cursor. Conversely, with the index scan, results
> immediately come back through the cursor method (which is more desirable).
> Thoughts?
Do you really need to use a cursor? It's generally less efficient than
doing things with a single SQL statement, depending on what exactly
you're doing.
--
Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED]
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
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