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Message Posted: Tue, 22 Apr 2003 @ 04:49:33 GMT


     
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Subj:   Re: Select * from mytable
 
From:   Prabhjot_Sodhi

Select * is an all amp retrieval. Only queries based on Unique Primary Index are a single AMP operations.

The result set is returned from the RDBMS after the entire query is fetched and the information is available in the SPOOL 1. If the you check the explain for the query, the informatio is first built in the spool, sorted (if required) and then sent back to the user.

If the user wants to see only the 200 rows use RANK or a cursor for the same.



     
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