Re: ORA-01555 snapshot too old? / NetWare-Database crashes

akaplan_at_psycfrnd.interaccess.com (Ari Kaplan) wrote:

>Friedel Hosenfeld <friedel_at_pz-oekosys.uni-kiel.d400.de> writes:
 

>>Hi, Kiel, 27-MAR-1996
 

>>I am experiencing a strange problem. One of our databases
>>is a Oracle7 (7.0.16.6.0) running on a Novell Netware (3.11)
>>server. We must use that old release because of some
>>compability reasons.
 

>>Since some days ago the database export doesn't work,
>>giving instead the message "ORA-01555: snapshot too old (rollback segment
>>too small)".
 

>>When I retrieve some tables, I get at some point (some particular
>>users) that message. Some other users are fine.
 

>>Very often - when I shut down and restart the database -
>>not only the database but the whole NetWare-Server crashes.
>>Sometimes the database crashes without any user action.
 

>>It's a very small database. I enlarged the tablespaces and
>>rollback segments but that didn't change the situation.
 

>>In the manual 4 reasons can be found, but only
>>the first two could be responsible in my case:
>>1. Insufficient Rollback Segments
>> -> but I increased them
>>2. Corrupted Rollback Segment
 

>>Because of the frequent crashes, I think that might be
>>the reason. How can I check that? Is there somebody
>>with experiences with that error message?
 

>>I will probably call the hotline but any hints are
>>welcome.
 

>>Thank you,
>> friedel

>>--
>> Friedel Hosenfeld http://www.pz-oekosys.uni-kiel.de/~friedel
>>Ecosystem Research Centre friedel_at_pz-oekosys.uni-kiel.d400.de
>> Schauenburger Str. 112
>> D-24118 Kiel * FRG blue in the face?
 

>Friedel,
 

>What you found in your manual may not fully explain the problems you have
>been having. The most likely cause IS that your rollback segments are too
>small. Specify larger INITAL and/or NEXT EXTENT sizes for your rollback
>segments. Considering that only some users get the error message, it seems
>that those users attached to that segment get the error, while the users
>attached to other segments do not get the error. Also be sure to set the
>OPTIMAL parameter of the rollback segment (if you are using Oracle7).
 

>Another problem could be caused while using Trusted ORACLE. If your
>interval between checkpoints is too small in a secondary database, you
>can get this error. Oracle recommends decreasing the value of the
>LOG_CHECKPOINT_TIMEOUT parameter in your "init.ora" file.
 

>As to your system crashing, I can't help you there. You could have a
>legitimate bug.
 

>If you are worried about corrupted rollback segments, then drop and
>recreate them as soon as possible!
 

>Good luck.
 

>-Ari Kaplan
>Independent Oracle DBA Consultant
 

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If you set OPTIMAL parameter, you are increasing the chances of getting snapshot too old error - don't you think ? Utrankas_at_coned.com (Sameer Utrankar)
212-460-1117 (W) Received on Mon Apr 08 1996 - 00:00:00 CEST