>
> One little thing. Did you shutdown sql2000 while testing
> postgresql? Remember that postgresql uses system cache.
> Sql2000 uses a large part of memory as buffer and it will not
> be available to operating system. I must say that, probably,
> results will be the same, but it will be a b
> De : Magnus Hagander [mailto:[EMAIL PROTECTED]
> Out of curiosity, what plan do you get from SQLServer? I bet
> it's a clustered index scan...
>
>
> //Magnus
>
I have a Table scan and Hashaggregate...
Stephane
---(end of broadcast)---
TI
John Arbash Meinel wrote :
>
> You might also try a different query, something like:
>
> SELECT DISTINCT cod FROM mytable ORDER BY cod GROUP BY cod;
> (You may or may not want order by, or group by, try the different
> combinations.)
> It might be possible to have the planner realize that all y
Qingqing Zhou wrote:
> "Alvaro Herrera" <[EMAIL PROTECTED]> writes
>
>>Interesting; do they use an overwriting storage manager like Oracle, or
>>a non-overwriting one like Postgres?
>>
>
>
> They call this MVCC "RLV(row level versioning)". I think they use rollback
> segment like Oracle (a.k.a "ver
"Alvaro Herrera" <[EMAIL PROTECTED]> writes
>
> Interesting; do they use an overwriting storage manager like Oracle, or
> a non-overwriting one like Postgres?
>
They call this MVCC "RLV(row level versioning)". I think they use rollback
segment like Oracle (a.k.a "version store" or tempdb in SQL S
On Mon, Aug 15, 2005 at 10:25:47AM +0200, Magnus Hagander wrote:
> SQL 2005 has "MVCC" (they call it something different, of course, but
> that's basicallyi what it is)
Interesting; do they use an overwriting storage manager like Oracle, or
a non-overwriting one like Postgres?
--
Alvaro Herrera
> Hi,
>
> I have a perfomance issue :
>
> I run PG (8.0.3) and SQLServer2000 on a Windows2000 Server
> (P4 1,5Ghz 512Mo) I have a table (320 rows) and I run
> this single query :
>
> select cod from mytable group by cod
> I have an index on cod (char(4) - 88 different values)
>
> PG = ~ 2
> ["very, very offtopic"]
> Ok. This comparition is just as useless as the other one,
> because it's comparing oranges with apples (It's funny
> anyway). I was just choosing an example in which you can see
> the best of postgresql against 'not so nice' behavior of
> mssql2000 (no service pack,
One little thing. Did you shutdown sql2000 while testing postgresql? Remember
that postgresql uses system cache. Sql2000 uses a large part of memory as
buffer and it will not be available to operating system. I must say that,
probably, results will be the same, but it will be a better test.
> I
On Sun, Aug 14, 2005 at 09:18:45PM -0400, Tom Lane wrote:
> Not really. There's been some speculation about implementing index
> "skip search" --- once you've verified there's at least one visible
> row of a given index value, tell the index to skip to the next different
> value instead of handing
"Steinar H. Gunderson" <[EMAIL PROTECTED]> writes:
> To me, it looks like he'll get 88 rows, not 3.2M. Surely we must be able to
> do something better than a full sequential scan in this case?
Not really. There's been some speculation about implementing index
"skip search" --- once you've verifie
Steinar H. Gunderson wrote:
>On Sun, Aug 14, 2005 at 07:27:38PM -0500, John Arbash Meinel wrote:
>
>
>>My guess is that this is part of a larger query. There isn't really much
>>you can do. If you want all 3.2M rows, then you have to wait for them to
>>be pulled in.
>>
>>
>
>To me, it looks
On Sun, Aug 14, 2005 at 07:27:38PM -0500, John Arbash Meinel wrote:
> If you are just trying to determine what the unique entries are for cod,
> you probably are better off doing some normalization, and keeping a
> separate table of cod values.
Pah, I missed this part of the e-mail -- you can igno
On Sun, Aug 14, 2005 at 07:27:38PM -0500, John Arbash Meinel wrote:
> My guess is that this is part of a larger query. There isn't really much
> you can do. If you want all 3.2M rows, then you have to wait for them to
> be pulled in.
To me, it looks like he'll get 88 rows, not 3.2M. Surely we must
Stéphane COEZ wrote:
>Hi,
>
>I have a perfomance issue :
>
>I run PG (8.0.3) and SQLServer2000 on a Windows2000 Server (P4 1,5Ghz 512Mo)
>I have a table (320 rows) and I run this single query :
>
>select cod from mytable group by cod
>I have an index on cod (char(4) - 88 different values)
>
>P
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