Hervé's Blog

Once a replication environment is set up, it's rarely forever. Adding tables to an Oracle GoldenGate replication group with minimal impact to the current replication is quite a difficult operation. This posting should help you with this task.

Last week, Oracle Ace Director Jonathan Lewis held an Oracle Optimizer Workshop at dbi services Basel Area. I would like to share some of the key learnings of this really interesting exchange I experienced together with my colleagues.

Last week, I attended the Microsoft TechDays for the first time. The Swiss 2011 "edition" took place in Bern. For me this is really a new challenge because I have never worked deeply with the Microsoft database platform "SQL Server".

Last week at a customer, I used DBUA to upgrade an Oracle database from 10g to 11g and the migration ran successfully. However, the day after I got a monitoring message that the diag directory is growing very rapidly.

Last week, I was not able to complete a backup because of the ORA-19566 error: "exceeded limit of 0 corrupt blocks". Here is what you can do to fix it.

While discussing with some tuning gurus, I was made aware about this feature. It is not so far from the adaptive cursor sharing perfectly described in Chris Antognini's blog: http://antognini.ch/papers/BindVariablePeeking_20090718.pdf

This feature compares the real execution (number of returned/actual rows - "A-rows") with some expectations (number of expected rows - "E-rows") and chooses another plan for the next executions if the difference between the expectation and the actual result is too big. "Cardinality Feedback" is not well documented in the Oracle documentation.

Recently, at a customer site, I had an Oracle Data Pump error which was not easy to localize. Here is the error I received during a DBIOWNER schema export with Data Pump:

Processing object type SCHEMA_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
ORA-39125: Worker unexpected fatal error in KUPW$WORKER.UNLOAD_METADATA while calling DBMS_METADATA.FETCH_XML_CLOB [TABLE_STATISTICS]
ORA-00942: table or view does not exist

Perhaps you know this situation: A developper or application owner quickly needs a test database to test new code or to validate changed code before implementing it. Sounds like a lot of work, but if you have Data Guard 11g, you can simply use the command "CONVERT TO SNAPSHOT STANDBY".