# multiple versus one row

**URL:** <https://forums.percona.com/t/multiple-versus-one-row/1388>\
**Category:** Other MySQL® Questions\
**Created:** [April 27, 2010, 8:11am UTC](https://forums.percona.com/t/multiple-versus-one-row/1388 "2010-04-27T08:11:15Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![markjones](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@markjones](https://forums.percona.com/u/markjones)\
**Post date:** [April 27, 2010, 8:11am UTC](https://forums.percona.com/t/multiple-versus-one-row/1388/1 "2010-04-27T08:11:15Z")

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From a purely speed-performance standpoint,

would it be faster to read a set of data if each item had its own row (ie using a while loop), or if that dataset were packed into a single row, and then parsed in my script?

Assume updates are infrequent, and the table is very large/trafficed.

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**Author:** ![xaprb](https://avatars.discourse-cdn.com/v4/letter/x/49beb7/32.png) [@xaprb](https://forums.percona.com/u/xaprb)\
**Post date:** [April 27, 2010, 12:38pm UTC](https://forums.percona.com/t/multiple-versus-one-row/1388/2 "2010-04-27T12:38:02Z")

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I really can’t answer such a vague question. In general, you should build a fully normalized schema, and then denormalize IF performance is a problem AND you can prove that this is needed to enhance performance.

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**Author:** ![markjones](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@markjones](https://forums.percona.com/u/markjones)\
**Post date:** [April 27, 2010, 1:13pm UTC](https://forums.percona.com/t/multiple-versus-one-row/1388/3 "2010-04-27T13:13:18Z")

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what about the question is “vague”?

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**Author:** ![xaprb](https://avatars.discourse-cdn.com/v4/letter/x/49beb7/32.png) [@xaprb](https://forums.percona.com/u/xaprb)\
**Post date:** [April 27, 2010, 1:50pm UTC](https://forums.percona.com/t/multiple-versus-one-row/1388/4 "2010-04-27T13:50:43Z")

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Everything that matters. What kind of data? What exactly? You have all kinds of unqualified terms in there like “very large” and “frequent.” In some cases one way is faster, in some cases another is. Don’t answer with details – I don’t want to know. It doesn’t matter. Start with a normalized schema, populate it with realistic test data, run realistic test queries against it, and measure what happens.

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**Author:** ![markjones](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@markjones](https://forums.percona.com/u/markjones)\
**Post date:** [April 29, 2010, 6:44pm UTC](https://forums.percona.com/t/multiple-versus-one-row/1388/5 "2010-04-29T18:44:26Z")

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Your advice sounds good. Thats what i needed. Thanks very much Troy!