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When transforming your data, you may find that you need data from multiple source tables in order to achieve your intended result. In such a case, you can create a materialized view from one Upsolver table in order to join it with your other table (considered the main table).
A materialized view in Upsolver functions as a set of key-value pairs that map values in a key column to a value defined when the view is first created.
When used in a query, the materialized view is joined with an Upsolver table on its key column. Then, using the key column values, the join operation returns the corresponding values that map within the materialized view.