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Range Scan Queries Do Not Use Full Width of Composite (Multi-Column) Index (Doc ID 2585491.1)

Last updated on SEPTEMBER 05, 2019

Applies to:

MySQL Server - Version 5.0 and later
Information in this document applies to any platform.

Symptoms

When executing a query with a composite index (that is, an index with multiple columns) and a range condition on a column that is not the last of the index, only part of the index is used to filter the rows. For example:


Visual Explain for the query in the example

This causes the query to perform badly.

Cause

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In this Document
Symptoms
Cause
Solution
References


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