I was trying to create about 40 rollback segments on an Oracle installation Vr. 7.3.4 on W-NT. I could not add more than 29 rollback segments in the init file. when starting up the instance with more than 29 rbs, an error which says that the buffer cache is full appears. What do I need to do? Am I missing something here?
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Number of Rollback segments does not exceed 29 1
- Thread starter sants
- Start date
Yup, you're missing something...<br>
<br>
The "rollback_segments" parameter in the "init.ora" file is only used for naming those rollback segments to be brought "online" by the instance upon startup. It does not create rollback segments and it does not represent a limit on the number of rollback segments. Quite literally, it simply provides the instance with list to issue the ALTER ROLLBACK SEGMENT xxx ONLINE command.<br>
<br>
I am doubtful that your error message says specifically that the "buffer cache is full"; I think rather that that is your interpretation of the message. Instead, it would be helpful if you displayed the actual numeric Oracle error number (i.e. "ORA-01562"
and alternately the actual text of the Oracle error message ("out of space to extend rollback segment in tablespace XXX", instead of an interpretation.<br>
<br>
It is possible that the string value for the ROLLBACK_SEGMENTS parameter simply exceeded some kind of length limit for WinNT or something like that. Log a TAR with Oracle Support and be prepared to email them your "init.ora" file...<br>
<br>
I've seen many databases on either UNIX or NT which have over 60 rollback segments. There is no hard limit on the number you can have, although the practical limit is really somewhere between 60 and 80 in most cases...<br>
<br>
In the meantime, you can simply perform ALTER ROLLBACK SEGMENT xxx ONLINE manually, if you wish...<br>
<br>
Thanks! Hope this helps...<br>
<br>
-Tim
<br>
The "rollback_segments" parameter in the "init.ora" file is only used for naming those rollback segments to be brought "online" by the instance upon startup. It does not create rollback segments and it does not represent a limit on the number of rollback segments. Quite literally, it simply provides the instance with list to issue the ALTER ROLLBACK SEGMENT xxx ONLINE command.<br>
<br>
I am doubtful that your error message says specifically that the "buffer cache is full"; I think rather that that is your interpretation of the message. Instead, it would be helpful if you displayed the actual numeric Oracle error number (i.e. "ORA-01562"
and alternately the actual text of the Oracle error message ("out of space to extend rollback segment in tablespace XXX", instead of an interpretation.<br><br>
It is possible that the string value for the ROLLBACK_SEGMENTS parameter simply exceeded some kind of length limit for WinNT or something like that. Log a TAR with Oracle Support and be prepared to email them your "init.ora" file...<br>
<br>
I've seen many databases on either UNIX or NT which have over 60 rollback segments. There is no hard limit on the number you can have, although the practical limit is really somewhere between 60 and 80 in most cases...<br>
<br>
In the meantime, you can simply perform ALTER ROLLBACK SEGMENT xxx ONLINE manually, if you wish...<br>
<br>
Thanks! Hope this helps...<br>
<br>
-Tim
-
1
- #3
I think that you are running into a problem with exceeding the max_rollback_segments init parameter. The default value for this parameter is 30, which would include the system rollback segment and any other rollback segments that you try to bring online. From the Oracle7 Server Reference Manual:<br>
<br>
MAX_ROLLBACK_SEGMENTS<br>
<br>
Default value : 30<br>
<br>
Range of values: 1-65536<br>
<br>
MAX_ROLLBACK_SEGMENTS specifies the maximum size of the rollback segment cache in the SGA. The number specified signifies the maximum number of rollback segments that can be kept online (that is, status of INUSE) simultaneously by one instance. For more information, see the Oracle7 Administrator's Guide.<br>
<br>
<br>
MAX_ROLLBACK_SEGMENTS<br>
<br>
Default value : 30<br>
<br>
Range of values: 1-65536<br>
<br>
MAX_ROLLBACK_SEGMENTS specifies the maximum size of the rollback segment cache in the SGA. The number specified signifies the maximum number of rollback segments that can be kept online (that is, status of INUSE) simultaneously by one instance. For more information, see the Oracle7 Administrator's Guide.<br>
<br>
sidvicious
Programmer
If you are getting the error ORA-01562, you should be able to create a new RBS datafile for the RB segments to extend into. [sig]<a href=mailto:erick@cmoremedical.com>erick@cmoremedical.com</a><br><a href=[/sig]
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