Datafile size minor than 4 Gb: is this a bug?

Question

Hi all! I have a tablespace made up by 1 datafile (size = 4 Gb). Oracle 9.2.0.4.0 (on Win2k server) seems incapable of managing this; in fact, I receive ora-04031: unable to allocate 8192 bytes of shared memory but the memory of Oracle is configured correctly. Resizing this tablespace and adding a new datafile so that every datafile is 2 Gb large, I don't receive the error any longer. what do you think about this?
Bye. Ste.

Answer 1

Hello everybody;
The Buffer Cache Advisory feature enables and disables statistics gathering for predicting behavior with different cache sizes. The information provided by these statistics can help you size the Database Buffer Cache optimally for a given workload. The Buffer Cache Advisory information is collected and displayed through the V$DB_CACHE_ADVICE view.
The Buffer Cache Advisory is enabled via the DB_CACHE_ADVICE initialization parameter. It is a dynamic parameter, and can be altered using ALTER SYSTEM. Three values (OFF, ON, READY) are available.
DB_CACHE_ADVICE Parameter Values
OFF: Advisory is turned off and the memory for the advisory is not allocated.
ON: Advisory is turned on and both cpu and memory overhead is incurred.
Attempting to set the parameter to the ON state when it is in the OFF state may lead to the following error: ORA-4031 Inability to allocate from the Shared Pool when the parameter is switched to ON. If the parameter is in a READY state it can be set to ON without error because the memory is already allocated.
READY: Advisory is turned off but the memory for the advisory remains allocated. Allocating the memory before the advisory is actually turned on will avoid the risk of ORA-4031. If the parameter is switched to this state from OFF, it is possible that an ORA-4031 will be raised.
Make sure too that you dont need to use RMAN program to make backup...baceuse the large pool is used to this too.
Regards to everybody
Nando