ORACLE - Materialized View LOG

Question

I have a table with a MVIEW Log, i would like to know if its suspicious to have :

SELECT count(*) from Table
8036132 rows

and

SELECT count(*) from MLOG$_Table
81657998 rows

Im asking this question because i get an error when trying to refresh my MVIEW ORA-30036 : unable to extend segment by 4 in undo tablespace 'UNDOTBS1' and i would like to know if something could be done except of extending the undo Tablespace?

Thanks in advance

Answer 1

Yes, that is suspicious.

You need materialized view logs to be able to do a fast refresh. A fast refresh is really an incremental refresh: a refresh that only refreshes the last changes to avoid having to do a complete refresh, which could be time-consuming. If your materialized view log contains 10 times as much rows as your original table, then you defeat the purpose of a fast refresh.

I'd first look into why this materialized view log contains this much rows. If you can avoid that, then your other problem - the ORA-30036 - will likely disappear as well.

Regards,
Rob.