How to set up oracle materialized view

Materialized views are pre-computed copies of the basic table that can be set up by: Create the basic table Create a materialized view using SQL statements to periodically refresh the materialized view to contain the latest data.

Oracle Materialized View Setting Guide

What is a materialized view?

A materialized view is a read-only copy of the pre-calculated results of the underlying tables stored in the database. It can improve the performance of queries that require frequent access to the same dataset.

How to set up a materialized view?

Step 1: Create the basic table

Create the base table for which materialized views are created.

Step 2: Create a materialized view

Create a materialized view using the following syntax:

 <code class="sql">CREATE MATERIALIZED VIEW [物化视图名称] AS SELECT [列名] FROM [基础表名称] [其他查询条件]</code>

For example:

 <code class="sql">CREATE MATERIALIZED VIEW sales_mv AS SELECT product_id, sum(quantity) AS total_sales FROM sales GROUP BY product_id;</code>

Step 3: Refresh the materialized view

After creation, the materialized view needs to be refreshed to contain the latest data. Refresh the materialized view with the following syntax:

 <code class="sql">REFRESH MATERIALIZED VIEW [物化视图名称];</code>

Optional steps: Create an index

Indexing on materialized views can further improve query performance. Use the following syntax to create an index:

 <code class="sql">CREATE INDEX [索引名称] ON [物化视图名称] ([列名]);</code>

hint:

• The name of the materialized view must be different from the name of the underlying table.
• A materialized view can contain columns from multiple underlying tables.
• Query criteria can be used to filter data contained in materialized views.
• The materialized view needs to be refreshed regularly to reflect any changes in the underlying table.
• Storage costs are considered based on the size of the materialized view and the refresh frequency.

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