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From:Michael Widenius Date:August 8 1999 2:50pm
Subject:unique key / multiple key - which is faster?
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>>>>> "Ralph" == Ralph Graulich <graulich@stripped> writes:

Ralph> Hi,
Ralph> I think the whole question fit in the subject line this time. I assume a
Ralph> unique key to be faster for ORDER BY or WHERE clauses, compared to a
Ralph> multiple key field? Isn't it?

The answer to the above is 'it depends'.  If you have many identical
values in a multiple key field then there will be a speed
difference. In other cases you will normally not notice any
difference.
.
Ralph> I wasn't able to determine a difference even when testing with about 90.000
Ralph> rows - wether the field was defined unique or multiple, the question took
Ralph> 0,07 seconds in both cases...

Regards,
Monty
Thread
unique key / multiple key - which is faster?Ralph Graulich8 Aug
  • unique key / multiple key - which is faster?Michael Widenius8 Aug
  • unique key / multiple key - which is faster?sinisa8 Aug