Re: Interesting query

The Search will not reflect the Updated Rows because of the Read-Consistency enforced by Oracle. When the User2 updates the Same rows which the User1 is trying to Select,the Old Data is Saved onto Rollback Segments which provides READ Consistency to the USER1 because his query started prior to the Update.

The Query has also got the possibility of Failing with ORA-1555 error Snapshot too old because the Commit by User2 will release the Rollback Segments from which the USER1's Query is Reading and might get overwritten by some Other transactions.

However if the search finishes at 11:10 and then if the User2 issues a new query,then it will be able to see the Previous Updates.

kstubm03_at_my-deja.com wrote:

> Suppose one user1 issues a select statement on a table 'temp' at 11:00
> and his search continues till 11:10, simultaneously
> another user2 updates the same table 'temp' at 11:01 and commits it at
> 11:05, now what is the result of the query of user1 which completes at
> 11:10, will he get the updated data or the old one, why???
>
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Received on Thu Jun 03 1999 - 16:03:18 CDT