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Editorial Team
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Asked: 2026-06-07T06:23:04+00:00

I’m curious how this is handled. I have a varchar(255) column named title that

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I’m curious how this is handled. I have a varchar(255) column named title that has the first 10 characters indexed.

If I create a MySQL query that orders by title, does it take advantage of that index solely, or does it ignore it, or do I have to issue a command to use that index?

For example let’s say I have two title items named:

This is the same thing
This is the same thing only slightly different

The first 10 chars are the same, so how does MySQL handle that? Does it use the prefix index up to the first 10 chars and then row by row index afterwards?

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1 Answer

  1. Editorial Team

    Well, it’s said that:

    The index can also be used even if the ORDER BY does not match the
    index exactly, as long as all of the unused portions of the index and
    all the extra ORDER BY columns are constants in the WHERE clause.

    But I strongly suggest checking this query with EXPLAIN, to see which path the optimizer will choose.

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