Re: LIOs from 10g when using CPU_TEST.SQL
- From: "Norman Dunbar" <norman.dunbar@xxxxxxxxxxxxxxxxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>, <att755@xxxxxxxxxxx>
- Date: Tue, 10 Jan 2006 15:06:16 +0000
Hi Tim,
Norman Dunbar.
Contract Oracle DBA.
Rivers House, Leeds.
Internal : 7 28 2051
External : 0113 231 2051
>>> "Tim Onions" <att755@xxxxxxxxxxx> 01/10/06 02:42pm >>>
<SNIP>
>> So what am I missing, why does 10g require less LIO? It clearly is
much
>> quicker whatever it is doing.
In addition to Connor's comments, Oracle 10g also has FAST DUAL access.
This is where there are zero LIOs to access dual when you don't specify
the actual contents of the row in DUAL.
SELECT * FROM DUAL or
SELECT DUMMY FROM DUAL
will incurr LIO, but
SELECT SYSDATE FROM DUAL or
SELECT USER FROM DUAL etc
will have zero LIO.
Cheers,
Norman.
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