supplementary log

Supplemental logging – how much space does it require?

by

Oracle at some point of decided that users might want to replicate the changes from the database to other targets. What they noticed, that the architecture of the database did not allow easy replication since the redo log did not contain information that would allow to identify the exact row, that has been modified. The … Read more

Oracle GoldenGate data filtering with WHERE and FILTER parameters the right way

by

One of the most trivial tasks for data replication is to define a replica of the table with just a subset of the rows from the source table. For example we would like just to replicate the ACCOUNTS table with some type (one column has some defined value). If you want to replicate that using Oracle GoldenGate and the account type may be modified then this is one of the most difficult tasks to achieve… Let’s find out why.

Read more

Oracle GoldenGate Integrated Replicat and NOSCHEDULINGCOLS

by

According to the documentation it is not allowed to use NOSCHEDULINGCOLS with ADD TRANDATA when you would use Integrated Replicat. Why would Oracle care for that? Let’s find out what can happen if you don’t apply the rules.

Read more

Oracle GoldenGate: What is ADD TRANDATA really doing?

by

In the process of data replication using Oracle GoldenGate the first step is assuring that all the needed information has been written to the database redo log. By default the database does not write all the information that might be needed by the replication process. That’s why some additional supplemental logging is needed.

According to the documentation supplemental logging is being added by the ADD TRANDATA command. A very good research about this subject has been made by Julian Dyke in the article about adding supplemental logging. But what does the  GoldenGate command actually do and which options should be used?

Read more