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10.08.2008 at 01:28AM PDT, ID: 23796496
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9.3

Is a unique multi-column index as good as a unique single column index.

Asked by iSac1984 in MySQL Server

Tags:

Using MySQL 5.0.45

I have a table that stores user profiles, the create statement looks something like

CREATE table profiles(
id_one int etc,
id_two int etc,
profile text,
PRIMARY (id_one, id_two))

Although the id_one id_two index uniquely identifies records, it makes for awkward multi-record retrieves. As a relative newcomer to this, my guess would be that an awkward query, with lots of:
WHERE (id_one = x and id_two = y) or (id_one = z and id_two = a) or ...

would be slower than a unique single column index.

Is it worth creating a separate unique single column index? Every byte counts, but if there'd be a good query speed improvement I'd be willing to make it.Start Free Trial
 
 
[+][-]10.08.2008 at 01:31AM PDT, ID: 22667058

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[+][-]10.08.2008 at 02:13AM PDT, ID: 22667220

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[+][-]10.08.2008 at 02:18AM PDT, ID: 22667245

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About this solution

Zone: MySQL Server
Tags: Databases, MySQL
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Solution Provided By: angelIII
Participating Experts: 1
Solution Grade: A
 
 
[+][-]10.08.2008 at 02:26AM PDT, ID: 22667283

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