Re: SOME QUESTIONS

Both ANALYZE statements generate statistics (stored in the catalog tables) that are used by the cost based optimizer in prepareing an execution plan for a query. The difference between ANALYZE ESTIMATE and ANALYZE COMPUTE is that ESTIMATE reads a sampleing of the table, whle COMPUTE reads the whole table. A tuning class I attended recently, it was stated that an ESTIMATE based on a 25 percent sampling of rows is as accurate as a full COMPUTE.

In article <892ch2$ni$1_at_nnrp1.deja.com>,   mihou_at_yahoo.com wrote:
> HI EVERYONE!
> CAN SOMEONE TELL ME WHAT IS THE WORTH OF:
> 1/ ANALYSE TABLE_NAME ESTIMATE STATISTICS;
>  
> 2/ANALYSE TABLE_NAME COMPUTE STATISTICS;
> 3/Can I have a good example in order to
> understand the proper use of MYSEQUENCE.CURRVAL?
> 4/What do I have to do to avoid MUTATING TABLE
> while using a trigger.?(an example would be
> appreciated)
> 5/Does someone know a site where I can submit
> questions on Forms,Reports and PL/SQL?
>  
> Thanks for your help.
>  
> Mihou
>  
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>

--
Ed Stevens
(Opinions are not necessarily those of my employer)


Sent via Deja.com http://www.deja.com/
Before you buy.