AWS Database Migration Service
User Guide (Version API Version 2016-01-01)

Target Metadata Task Settings

Target metadata settings include the following:

  • TargetSchema – The target table schema name. If this metadata option is empty, the schema from the source table is used. AWS DMS automatically adds the owner prefix for the target database to all tables if no source schema is defined. This option should be left empty for MySQL-type target endpoints.

  • LOB settings – Settings that determine how large objects (LOBs) are managed. If you set SupportLobs=true, you must set one of the following to true:

    • FullLobMode – If you set this option to true, then you must enter a value for the LobChunkSize option. Enter the size, in kilobytes, of the LOB chunks to use when replicating the data to the target. The FullLobMode option works best for very large LOB sizes but tends to cause slower loading.

    • LimitedSizeLobMode – If you set this option to true, then you must enter a value for the LobMaxSize option. Enter the maximum size, in kilobytes, for an individual LOB.

  • LoadMaxFileSize – An option for PostgreSQL and MySQL target endpoints that defines the maximum size on disk of stored, unloaded data, such as .csv files. This option overrides the connection attribute. You can provide values from 0, which indicates that this option doesn't override the connection attribute, to 100,000 KB.

  • BatchApplyEnabled – Determines if each transaction is applied individually or if changes are committed in batches. The default value is false.

    If set to true, AWS DMS commits changes in batches by a pre-processing action that groups the transactions into batches in the most efficient way. Setting this value to true can affect transactional integrity, so you must select BatchApplyPreserveTransaction in the ChangeProcessingTuning section to specify how the system handles referential integrity issues.

    If set to false, AWS DMS applies each transaction individually, in the order it is committed. In this case, strict referential integrity is ensured for all tables.

    When LOB columns are included in the replication, BatchApplyEnabledcan only be used in Limited-size LOB mode.

  • ParallelLoadThreads – Specifies the number of threads AWS DMS uses to load each table into the target database. The maximum value for a MySQL target is 16; the maximum value for a DynamoDB target is 32. The maximum limit can be increated upon request.

  • ParallelLoadBufferSize – Specifies the maximum number of records to store in the buffer used by the parallel load threads to load data to the target. The default value is 50. Maximum value is 1000. This field is currently only valid when DynamoDB is the target. This parameter should be used in conjunction with ParallelLoadThreads and is valid only when ParallelLoadThreads > 1.