Part 114: Refreshing Materialized Views: Concurrent Refresh

Because materialized views are cached snapshots, they must be refreshed as underlying data updates.

1. Refresh Syntax

-- Standard refresh (Locks the view against reads during refresh):
REFRESH MATERIALIZED VIEW mv_monthly_category_sales;

-- Concurrent refresh (Zero downtime! Allows reads while refreshing):
REFRESH MATERIALIZED VIEW CONCURRENTLY mv_monthly_category_sales;

(Note: CONCURRENTLY requires a unique index on the materialized view).

Key Takeaways

• Always create a unique index on materialized views so you can use REFRESH ... CONCURRENTLY in production without blocking reads.

In Part 115, we explore User-Defined Functions (UDF): Scalar Functions!