Oracle

Hevo ingests data from your Oracle database in real-time using three replication modes: Custom SQL, Table, or Redo Log.

Read Pipeline Modes.

Setting up Redo log based replication

  1. Enable ARCHIVE LOG mode

    Logminer reads the archived redo log files. Hence its necessary to enable archiving to do redo based replication. To know the current log mode, run this command

    SELECT LOG_MODE FROM "V$DATABASE";
    

    If it returns NOARCHIVELOG, enable archive mode using the steps mentioned here in case of self hosted oracle servers.

    In case of AWS RDS servers, run the following command

    exec rdsadmin.rdsadmin_util.set_configuration('archivelog retention hours',72);
    
  2. Enable Supplemental logging

    Supplemental logging is required to make sure that the server logs all columns of every change event to the redo logs. Enabled supplemental logging at the database level.

    ALTER DATABASE ADD SUPPLEMENTAL LOG DATA ALL COLUMNS
    

    or at the table level

    ALTER TABLE <SCHEMA_NAME>.<TABLE_NAME> ADD SUPPLEMENTAL LOG DATA ALL COLUMNS
    

    In case of AWS RDS servers, run the following command to enable supplemental logging.

    exec rdsadmin.rdsadmin_util.alter_supplemental_logging('ADD','ALL');
    

    Verify if supplemental logging is enabled.

    SELECT SUPPLEMENTAL_LOG_DATA_MIN FROM "V$DATABASE"
    

    This should return YES or IMPLICIT.

Object Settings

Object settings must be configured if the Pipeline mode is Table. To do this:

  • After specifying the settings for the Oracle Source, in the SELECT OBJECTS YOU WANT TO REPLICATE page, select the objects to be replicated.

    Note: Each object represents a table in your database.

  • In the CONFIGURE SOURCE OBJECTS page, specify the query mode to be used for each selected object.

Last updated on 19 Oct 2020