MySQL Optimization

Writing Fast Queries

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EXPLAIN SELECT (continued)

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Extra information

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Using filesort

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An extra pass is required to sort the records

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This can be slow at times

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Using index

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Data will come from the index rather than rows

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This can speed things up

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Using temporary

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MySQL will create a temporary table

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It’ll be a disk-based table if it’s too large

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Where used

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The where clause will be applied to this table

Copyright 2002, Jeremy Zawodny (Jeremy@Zawodny.com)