Re: why db block gets = 0?

niy38_at_hotmail.com (Niy) wrote:
>
> In another window:
> SQL> alter system flush shared_pool;
>
> System altered.

So, you just gave Oracle amnesia.

>
> back to original window:
>
> SQL> /
>
> ID
> ----------
> 1
>
> Execution Plan
> ----------------------------------------------------------
> 0 SELECT STATEMENT Optimizer=CHOOSE
> 1 0 TABLE ACCESS (FULL) OF 'T'
>
> Statistics
> ----------------------------------------------------------
> 181 recursive calls
> 0 db block gets
> 23 consistent gets ----------- why there are so many consistent gets

Oracle is waking up from Amnesia, and it is wondering: Who the Hell are you?
What the Hell is "T"?
Do you have permissions on "T"?
Where is "T"?
What are the columns of "T"?
Do I have statistics on "T"?
etc. etc.
To answer these questions, it has to query the system tables.

> after flushed shared_pool?
> 0 physical reads
> 0 redo size
> 373 bytes sent via SQL*Net to client
> 499 bytes received via SQL*Net from client
> 2 SQL*Net roundtrips to/from client
> 2 sorts (memory) ------------------- sort again ?

It probably had to do some "group by"s when reading the system tables. Why are you obsessed with the minutiae? You buy server software so that you don't have to know every single detail! So unless you are hunting down a performance problem....

Xho

-- 
-------------------- http://NewsReader.Com/ --------------------
Usenet Newsgroup Service                        $9.95/Month 30GB