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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Slow running Query.
Thanks Lex, you are right. good point for Kumar if this has some impact in
his query.
-------Original Message-------
From: oracle-l_at_freelists.org
Date: 06/22/04 13:30:53
To: oracle-l_at_freelists.org
Subject: RE: Slow running Query.
Juan,
in your case you don't even need the nvl function -- because the result is
always 3.
the problem occurs with the empty set. check this out:
SQL> create table blah(c1 number);
Table created.
SQL> select nvl(sum(c1),0), sum(nvl(c1,0)) from blah;
NVL(SUM(C1),0) SUM(NVL(C1,0))
-------------- --------------
0
SQL>
Kind regards,
Lex.
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org]On Behalf Of Juan Carlos Reyes
Pacheco
Sent: Tuesday, June 22, 2004 18:21
To: oracle-l_at_freelists.org
Subject: RE: Slow running Query.
Hi Lex, why you say that, could you showme why please
I show you why I say is the same:
SQL> select * from test;
TEST
2
Transcurrido: 00:00:00.00
SQL> select count(*) from test where test is null;
COUNT(*)
Transcurrido: 00:00:00.00
SQL> select sum(nvl(test,0)) from test;
SUM(NVL(TEST,0))
Transcurrido: 00:00:00.00
SQL> select nvl(sum(test),0) from test;
NVL(SUM(TEST),0)
Transcurrido: 00:00:00.00
-------Original Message-------
From: oracle-l_at_freelists.org
Date: 06/22/04 12:43:39
To: oracle-l_at_freelists.org
Subject: RE: Slow running Query.
Juan,
unfortunately sum(nvl(column,0)) is not equivalent to nvl(sum(column),0)..
Kind regards,
Lex.
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org]On Behalf Of Juan Carlos Reyes
Pacheco
Sent: Tuesday, June 22, 2004 17:15
To: oracle-l_at_freelists.org
Subject: RE: Slow running Query.
Hi, I will do t he following
Try creating function indexes on composed columns you are queryin and tellme
if this improves something
For example you are using as_date in the where column, but you don't have a
index on substr(ca_date,1,4,....
Only to avoid unncesary plsql work
1. instead sum(nvl(column,0)) I'll use nvl(sum(column),0
2. instead of decode use case
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