RE: reading the SGA from my own program

Hi Brandon

Another example, even if the idea is not to read but to modify the SGA... 4) To test particular conditions. E.g. in 10.2 I used to modify blocks in the buffer cache to check how/when checks performed by DB_BLOCK_CHECKSUM=FULL takes place, i.e. to produce "good" logical corruptions.

Chris

> -----Original Message-----
> From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-
> bounce_at_freelists.org] On Behalf Of Anjo Kolk
> Sent: Monday, August 21, 2006 8:03 PM
> To: Allen, Brandon
> Cc: tanel.poder.003_at_mail.ee; jeremiah_at_ora-600.net; Oracle Discussion
> List
> Subject: Re: reading the SGA from my own program
>
>
> There are a couple of resaons why this is (was) valid:
> 1) Overhead
> Sampling the v$SESSION_WAIT once a second is something that
> can't be done with normal queries (not completely true) and mapping
> different pointers.
> A join of v$session_wait, v$session and v$sqlarea is rather
> expensive if you want to find the current sql statement that causes
> the wait, very cheap with
> direct SGA attach.
> 2) Information
> Sometimes to get usefull info from V$ or X$ tables, one needs to
> join them and even then it becomes not possible. By having access
> to the SGA
> one can join structures together that can't be done in normal
> SQL.
> 3) Geeky stuff
> Really cool to do ;-)
>
> Anjo.

--
http://www.freelists.org/webpage/oracle-l