GDA interim benchmarking synopsis
mrj001 at shaw.ca
Thu Feb 14 15:09:26 EST 2008
Derek Atkins wrote:
> Mark Johnson <mrj001 at shaw.ca> writes:
>> SQLite and MySql are completely opposite as to which queries perform
>> well and poorly. That's why I want to see if I can adjust the queries
>> and indices to do better.
> I'm really beginning to wonder if we need to write special SQL
> based on the database we're using in order to tune the performance
> because of issues like this? Yes, I know that that sort of defeats
> the purpose of using a library like GDA, but if GDA can't form
> an optimal query then it might behoove us to do the right thing
> rather than hope they do.
I hope not, but we are talking not about minor differences in
performance, but orders of magnitude. I was absolutely floored at
MySql's performance with sub-queries. I do have a couple of things to
try with it, though:
1. creation of a secondary index on slots.obj_guid
2. There is a section of the MySql manual on optimizing this stuff.
Maybe it has something helpful.
>> I may take a break from this to see about patching the PostgreSQL
>> provider to test it, too.
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