(dokumnr);
-Original Message-
From: Andrus [mailto:[EMAIL PROTECTED]
Sent: Tuesday, December 02, 2008 10:59 AM
To: Scott Carey; pgsql-performance@postgresql.org; PFC
Subject: Re: [PERFORM] analyzing intermediate query
Scott,
>Often times, switching an inner subselect that requires a distinct
Scott,
Often times, switching an inner subselect that requires a distinct to a
group by on that column yields better results. In this case, the IN should
be equivalent, so it probably will not help. This would look like:
SELECT dok.*
FROM dok
JOIN (SELECT dokumnr FROM temptbl GROUP BY dok
[EMAIL PROTECTED]
Sent: Tuesday, December 02, 2008 7:50 AM
To: pgsql-performance@postgresql.org; PFC
Subject: Re: [PERFORM] analyzing intermediate query
> Oh, I just thought about something, I don't remember in which version it
> was added, but :
>
> EXPLAIN ANALYZE SELECT sum(colu
Oh, I just thought about something, I don't remember in which version it
was added, but :
EXPLAIN ANALYZE SELECT sum(column1) FROM (VALUES ...a million
ntegers... ) AS v
Postgres is perfectly happy with that ; it's either a bit slow (about 1
second) or very fast depending on how you view th
My list can contain 1 .. 10 records and table contains 300
records and is growing.
Ah. No IN(), then ;)
Temp table + ANALYZE seems your only option...
In 8.3 or 8.4 I think that IN() or temp table produce exactly the same
result.
Andrus.
Oh, I just thought about something,
My list can contain 1 .. 10 records and table contains 300
records and is growing.
Ah. No IN(), then ;)
Temp table + ANALYZE seems your only option...
In 8.3 or 8.4 I think that IN() or temp table produce exactly the same
result.
Andrus.
--
Sent via pgsql-performance mailing l
My list can contain 1 .. 10 records and table contains 300
records and is growing.
Ah. No IN(), then ;)
Temp table + ANALYZE seems your only option...
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Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
To make changes to your subscription:
Generally if you know your temptbl will always contains a few rows (say,
generally a few and never more than a few thousands) it is better to use
something like that :
- get list of items
- SELECT * FROM table WHERE id IN (...)
My list can contain 1 .. 10 records and table contains 3
I noticed that query
SELECT dok.*
FROM dok
JOIN (SELECT DISTINCT dokumnr FROM temptbl ) x USING(dokumnr);
is slow in 8.1.4
I cannot use explain analyze since this query uses results from
temporary table temptbl which is not available.
Generally if you know your temptbl will always contai
I noticed that query
SELECT dok.*
FROM dok
JOIN (SELECT DISTINCT dokumnr FROM temptbl ) x USING(dokumnr);
is slow in 8.1.4
I cannot use explain analyze since this query uses results from temporary
table temptbl which is not available.
Sometimes innter table returns only 1 row so maybe seq s
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