Dms

• Managed databsse migration service
• Runs using an EC2 replication instance
• Either Source or Target has to be within AWS
• A replication instance uses replication tasks
• Jobs can be Full Load i.e one of migration of all data, Full Load + CDC (change data capture) first does full load & any changes made after the full load, CDC only this assumes full load is done by some other tool & then only changes are replicated
• DMS does not support schema conversations natively
• AWS provides SCT i.e. Schema Conversion Tool for schema transofmration. This is used from one database engine to another.
• SCT is not used for migrating between same engine
• SCT works for OLTP as well as OLAP transformation
• For large i.e mmulti-TB db transfer, one can
  • Use SCT to extract data & move to snowball
  • Ship snoball & load data in S3
  • DMS is used to migrate from S3
  • CDC is used to sync any further changes