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Showing posts with label Heaps. Show all posts
Showing posts with label Heaps. Show all posts

Thursday, 17 February 2011

Seeking Without Indexes

Seeking Without Indexes

A seek can contain one or more seek predicates, each of which can either identify (at most) one row in a unique index (a singleton lookup) or a range of values (a range scan).

When looking at an execution plan, we often need to look at the details of the seek operator in the Properties window to see how many operations it is performing, and what type of operation each one is.

As seen in the first post of this mini-series, When is a Seek not a Seek? the number of hidden seeking operations can have an appreciable impact on performance.