What are snapshots? What are materialized views & where do we use them? What is a materialized view log? - ETL

What are snapshots? What are materialized views & where do we use them? What is a materialized view log?

- Snapshots are copies of read-only data of a master table.

- They are located on a remote node that is refreshed periodically to reflect the changes made to the master table.

- They are replica of tables

Views

- Views are built by using attributes of one or more tables.

- View with single table can be updated, whereas view with multiple tables cannot be updated

Materialized View log

- A materialized view is a pre computed table that has aggregated or joined data from fact tables and dimension tables.

- To put it simple, a materialized view is an aggregate table.