Robert Soeding wrote:
>> 1. What configuration changes have you made?
>
> None, both installations are default configured.
You'll want to do at least some tuning on PG. Try the URL below for a
quick introduction - just the basic stuff is a good start.
http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html
>> 2. How many concurrent connections was this?
> One.
OK. That keeps things nice and simple.
>> 3. Were you selecting 1000 rows (LIMIT 1000), selecting all the
>> rows (and only fetching 1000) or actually defining an SQL cursor.
>
>
> I used "LIMIT 1000", resp. "TOP 1000" statements.
OK. The reason I asked was that if you ask for 1000000 rows, then PG
will find them all and return them all in a bunch. Most other servers
return the first row once it's available.
>> 4. What was the load on the machine - CPU or DISK peaking? 5. What
>> was the RAM usage like?
>
> CPU (< 10%) and RAM (<10%) usage were very low.
>
> - I guess (as you mentioned below) it's the NT file system. When
> running PostgreSQL queries I can hear the harddisk buzzing, but not
> with SQL Server queries.
If you're seeing hard-disk activity that means the data isn't cached.
> On the other hand, if an application has to "fight" against the file
> system, I would suppose it to increase RAM and CPU usage
> significantly.
It shouldn't be fighting the file system, but it does use it, and rely
on it for caching (rather than bypassing your filesystem cache). For
MS-SQL server I'm guessing you're allocating a lot of memory to SQL
server and not much to the file-cache. For PG you'll want it the other
way around.
--
Richard Huxton
Archonet Ltd