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A comment on Let's make the web faster: Tools to discover and improve your site performance. Parent comment

Re:Let's make the web faster: Tools to discover and improve ... by patio11 on Wednesday December 08, 2010 @05:25AM (#1982440)
I am unaware of a commonly used database where primary keys are not indexed by default. Granted, on a good day I can spell SQL correctly, but it was my impression that primary keys imply an index by definition. Can someone rectify my understanding?
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Re:Let's make the web faster: Tools to discover and improve ... by JoachimSchipper on Wednesday December 08, 2010 @05:35AM (#1982453)
Yeah, you're right. Call it slapping an index on the column holding actual data. My bad.

(The reason that primary keys tend to be auto-indexed is simple: to verify uniqueness, you need to check whether the primary key of the record being inserted is already in any record. Doing this without indices would be painfully slow.)

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