Ask the Expert

Total size of SGA greater than what was allocated

Please note that we are running Oracle under SCO UNIX 5.0.5. The allocated SGA is as following:
 Total System Global Area    1064706136 bytes
 Fixed Size                       41880 bytes
 Variable Size                204623040 bytes
 Database Buffers             858992640 bytes
 Redo Buffers                   1048576 bytes
I observed that the behavior of the SGA is not acceptable because sometimes, when I execute the following query:
 I get the total size of the SGA greater than what we
 allocated, and there is
 no free memory.
 Any ideas regarding this issue? 

    Requires Free Membership to View

V$SGASTAT does not include everything. For instance, it does not include the "Fixed Size" of the SGA. So you will see a difference between the SHOW SGA command and the sum of bytes from V$SGASTAT.

You should, however, see some free memory from V$SGASTAT. For instance, use the following query:

SQL> select * from v$sgastat where name='free memory';

POOL        NAME                                 
----------- --------------------------
shared pool free memory                      
Here, I have 7MB free in my Shared Pool. You don't want a lot of free memory however since this will be wasting space.

For More Information

This was first published in November 2002

There are Comments. Add yours.

TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
Sort by: OldestNewest

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to: