Re: More Prelimiary DBT-2 Test Results with PostgreSQL

On 24 Sep, Greg Stark wrote:
> markw(at)osdl(dot)org writes:
>
>> On 22 Sep, Greg Stark wrote:
>> > Are those response times in the right unit? 7-10s?
>>
>> The plans (http://developer.osdl.org/markw/74/db/plan0.out) don't show
>> any table scans. They appears to be mostly index scans. There aren't
>> any batch updates.
>
> Would it be easy to generate this file doing "explain analyze" instead? It
> would give me a better idea what you're doing since I don't know much about
> the data.

No problem: http://developer.osdl.org/markw/misc/plana.out

> Just looking at the plans I don't see how any of these queries could possibly
> take 7s. There are two that could possibly take a few hundred milliseconds,
> the others I would expect to be under 100ms. Obviously this is all just a gut
> reaction, not having looked at the data, and it would depend on the hardware.
> But none of the queries look like they should measuring reaction times in
> seconds.

I have a 4-way 1.5Ghz Xeon with 256KB cache and hyper-threading enabled
and 4GB of memory. Although the disk controllers are reducing my
physical memory by about 500MB. I can provide more details if you like.

>> Right, and when this thing is tuned better, I expect the transactions to
>> be down in the 20-200ms range. I do have about 70 drives for the
>> database, so it really shouldn't be i/o bound at with the size of the
>> database I'm using now, which is about 20 or 30 GB.
>
> 70 drives for 20-30G? That's pretty extreme.

Yeah, we're starting small but we'll increase the database size as we
move along.

Mark