2.1.2 Database Requirements

This section contains Oracle GoldenGate requirements that are specific to the Oracle Database. These apply to both capture modes unless explicitly noted.

  • Classic Extract captures all the columns by default. These behaviors do not affect like to like replications. However, with a replication to data warehouse, all the columns might have to be updated. If you are using the DBMS_LOB.LOADFROMFILE procedure to update a LOB column only and your supplemental log is on all the columns, Integrated Extract captures the key columns and LOB improving performance.

    If you are converting from Classic Extract to Integrated Extract, you must use one of the following parameters to ensure that the Extract operates correctly:

    • Use KEYCOLS to add all columns (except LOB).

    • Use LOGALLSUPCOLS to control the writing of supplementally logged columns.

  • Ensure that your database has minimal supplemental logging enabled.

  • Database user privileges and configuration requirements are explained in Establishing Oracle GoldenGate Credentials in Using Oracle GoldenGate for Oracle Database.

  • If the database is configured to use a bequeath connection, the sqlnet.ora file must contain the bequeath_detach=true setting.

  • Oracle Databases must be in ARCHIVELOG mode so that Extract can process the log files.

  • Oracle Databases must be in FORCE LOGGING mode to ensure that all transactional data is written to Redo.

  • Disk space is also required for the Oracle GoldenGate Bounded Recovery feature. Bounded Recovery is a component of the general Extract checkpointing facility. It caches long-running open transactions to disk at specific intervals to enable fast recovery upon a restart of Extract. At each bounded recovery interval (controlled by the BRINTERVAL option of the BR parameter) the disk required is as follows: for each transaction with cached data, the disk space required is usually 64k plus the size of the cached data rounded up to 64k. Not every long-running transaction is persisted to disk. For complete information about Bounded Recovery, see the BR parameter in Reference for Oracle GoldenGate.