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Re: ideas to use ora hash

From: Glenn Santa Cruz <glenn.santacruz_at_gmail.com>
Date: Wed, 22 Mar 2006 19:44:22 -0600
Message-ID: <277902c40603221744y588f2421s36383aac553e875c@mail.gmail.com>


create table t1 (x int);
insert into t1select rownum from all_objects where rownum <= 10; insert into t1 select * from t1; -- t1 now has "duplicate" rows: 1,1,2,2,3,3, ...

select * from t1 minus select 15 from dual; -- t1 minus a non-existent t1 value

Run this. You'll see that the minus on t1 (regardless of the set you're "subtracting") will remove duplicate rows from t1. That's what I meant by saying "be careful with minus". You might want this behavior, or you might not -- it's entirely up to you to decide what you consider "differences" between two tables (whether the existence of extra rows in one table qualifies as a difference).

Glenn

On 3/22/06, Juan Carlos Reyes Pacheco <juancarlosreyesp_at_gmail.com> wrote:
> Thanks Glen, but I didn't got the idea could you give an example :) please.
>

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Received on Wed Mar 22 2006 - 19:44:22 CST

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