Oracle-L: Re: Query rewrite help needed

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Mon, 10 Mar 2003 07:23:52 -0800
Message-ID: <F001.005647CB.20030310072352@fatcity.com>

Tim,

Following your trunc() line, have you come across this feature of 9.2 (and some earlier versions) -

create index t1_i2 on t1(d1);
analyze table t1 compute statistics;

select * from t1
where trunc(sysdate) = '01-Dec-2002';

Execution plan:

table access (by index rowid) of 'T1'

index (range scan) of 'T1_I2' (non-unique)

Note the index name, in particular.

It's another little feature that takes away some of the hassle of getting the text
'just so'.

How does it do it, you ask ? I'll leave it open for a while in case anyone wants to have some fun guessing.

All correct answers received by 5 pm (GMT) tonight will go into a prize draw.
Note - Answers must be written on the back of a USD$100 bill and delivered by hand to the author's bank manager be eligible.

Regards

Jonathan Lewis
http://www.jlcomp.demon.co.uk

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Original Message ----- To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com> Sent: 10 March 2003 13:43

> In the same vein, I'd suggest rewriting:
>
> and trunc(a.seg_dep_date_time) = :seg_dep_date
>
> as:
>
> and a.seg_dep_date_time >= :seg_dep_date
> and a.seg_dep_date_time < :seg_dep_date + 1
>

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Author: Jonathan Lewis
  INET: jonathan_at_jlcomp.demon.co.uk

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Received on Mon Mar 10 2003 - 09:23:52 CST