What is Oracle Supplemental Logging?


Here is a quick synopsis on supplemental logging. I have simply distilled the information gathered from The “Oracle Database Utilities” Manual, Chapter 17 for 10g R2. Because Streams uses logminer and logminer required supplemental logging, streams requires supplemental logging.

Types of Supplemental Logging:
You can add supplemental logging at either the table level, or the database level.

Database Level Supplemental Logging:
There are two types of database level supplemental logging: minimal logging, and identification key logging. Identification key logging can impose significant overhead. Minimal Supplemental Logging “logs the minimal amount of information needed for LogMiner to identify, group, and merge the redo operations associated with DML changes.” You turn it on with:

ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;

Database Level Identification Key logging is necessary when the redo logs will not be mined at the source database instance. Here are the options:

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