There's a chance that you could gain from quoting the '4' and '6' if those orders.id_status isn't a pure int column and is indexed.



Thomas F. O'Connell
Co-Founder, Information Architect
Sitening, LLC
110 30th Avenue North, Suite 6
Nashville, TN 37203-6320

On Oct 19, 2004, at 12:49 PM, Contact AR-SD.NET wrote:

Is there a solution to make it faster?
At the end I need only in the query the id_status =4 and 6, but if I write
in the sql query (where condition) where id_status in (4,6), the explain
says the same(the slow version).

For example:
SELECT count( FROM orders o
INNER JOIN report r ON
INNER JOIN status s ON
INNER JOIN contact c ON
INNER JOIN endkunde e ON
INNER JOIN zufriden z ON
INNER JOIN plannung v ON
INNER JOIN mpsworker w ON
INNER JOIN person p ON = w.id_person
WHERE o.id_status in (4,6);

The result for this query is also without index searches.

I really have to make this query a little more faster. Suggestions?


----- Original Message -----
From: "Tom Lane" <[EMAIL PROTECTED]>
To: "Andrei Bintintan" <[EMAIL PROTECTED]>
Sent: Tuesday, October 19, 2004 7:52 PM
Subject: Re: [PERFORM] Index not used in query. Why?

"Andrei Bintintan" <[EMAIL PROTECTED]> writes:
Hi to all! I have the following query. The execution time is very big,
doesn't use the indexes and I don't understand why...

Indexes are not necessarily the best way to do a large join.

If I use the following query the indexes are used:

The key reason this wins seems to be that the id_status = 4 condition
is far more selective than id_status > 3 (the estimates are 52 and 36967
rows respectively ... is that accurate?) which means that the second
query is inherently about 1/700th as much work. This, and not the use
of indexes, is the fundamental reason why it's faster.

regards, tom lane

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