Re: HELP URGENT CORRUPTED DATA

Hello Paula

I played a little with MINUS lately and found that with MINUS you do not get the difference between the two selects. MINUS works by subtracting from the first select the rows that you get in the second select.
If there are more rows in the second select you will not know about it. So if in the first select you get 1,2 and in the second select you get 1,2,3 the result will be no rows.
You need to do the MINUS both ways to be sure that the data is the same.

As to your question about hidden characters just do: select 'abc' from dual MINUS select 'abc' || chr(13) from dual; and you will see that you get a row, while: select 'abc' from dual MINUS select 'abc' from dual; return no rows.

Adar Yechiel
Rechovot, Israel

Paula Stankus wrote:

> Alex,
>
> Add to that that the system I have inherited had nologging and was not
> properly synchronizing their backups to nologging and wallah! The
> problem is eye-balling the data we come up with no differences.
>
> My question is: if there are hidden characters in data elements (so
> there are differences but we don't see them) - will a MINUS find them?
>
> :)
>
> <http://us.rd.yahoo.com/mail_us/taglines/postman7/*http://us.rd.yahoo.com/evt=39666/*http://messenger.yahoo.com>

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