Title: Message
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My view is...
You can either have
Select ..blah..blah..blah...where col =
'A'
OR col='B'
OR col='c'
also, you can wrtie..
Select...blah..blah..blah....where
col='A'
union
select...blah..blah..blah...where
col='B'
union
select...blah..blah.blah..where
col='C'
Or better.
Select ...blah..blah..blah....where col in
('A','B','C') ; (with proper index in 'col')
Its really upto you.
-Arun.
----- Original Message -----
Sent: Tuesday, June 24, 2003 11:25
AM
Subject: RE: OR Vs UNION
IMHO ...
Cannot be.. the Access Path Taken is Different.. "OR" is Transfered to
Inlist Iterator usually ...
Best Regards,
Ganesh R
DID : +65-6215-8413
HP
: +65-9067-8474
===========================================
Live to
learn... forget... and learn
again.
===========================================
I believe OR is internally transformed to UNION (or UNION
ALL) ??
The answer you are looking is ... test and measure it in
_your_ _environment_.
Raj
--------------------------------------------------------------------------------
Rajendra dot Jamadagni at nospamespn dot com
All Views expressed in this email are strictly
personal.
QOTD: Any clod can have facts, having an
opinion is an art !
>----- ------- Original Message ------- -----
>From: [EMAIL PROTECTED]
>To: Multiple recipients of list ORACLE-L
><[EMAIL PROTECTED]>
>Sent:
Mon, 23 Jun 2003 21:34:52
>
>
>
>
>
>Hi All,
>
>Could someone explain to me which
one is best in
>the following two queries
>w.r.t performance?
>
>Thanks
>Sami
>
>Query1)
>========
>select distinct empployee_id
from employees where
>department_id=10 or
>department_id=20
>/
>
>Query2)
>=======
>select employee_id from
employees where
>department_id=10
>union
>select employee_id
from employees where
>department_id=20
>/
>
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