How to use Materialized View in SQL

SQL Tips

Materialized views are a powerful feature in SQL databases that can significantly enhance query performance. They work by storing the results of a query as a physical table, which can then be quickly accessed without having to re-execute the original query. This precomputed data structure is particularly useful for complex queries involving large datasets or multiple joins.

This should work in every RDBMS.

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Two important notes about Materialized view:

• Materialized view is essentially a normal table under the hood with query logic for populating it thus you can index it

• The data is basically static until you refresh it at which time it's flushed and the data is replaced by the result of the query at the new run time. They're particularly good when the performance to run the query is poor but the data doesn't have to be exact or up to date.

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Example:

Create the materialized view

CREATE MATERIALIZED VIEW my_table_mv
AS
SELECT
	id,
	AVG(value),
	COUNT(*)
FROM
	my_table
GROUP BY
id

Using the Materialized View

SELECT * FROM my_table_mv

Using materialized view can help cut down on time to run complex queries when you don't need super up to date data.

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NOTE:

The data does not automatically update. You will need to schedule a refresh to update the data in the materialized view.

REFRESH

REFRESH MATERIALIZED VIEW my_table_mv

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Thank you for reading!

See you next time!

Best,
Cameron Seamons (LinkedIn)