Datasheet

Chapter 1: Being Objective: Re-Examining Objects in SQL Server
Figure 1-1
Aggregations performed in the view are precalculated and stored as part of the index; again, this
means that the aggregation is performed one time (when the row is inserted or updated), and
then can be read directly from the index information.
Inserts and deletes have higher overhead because the index on the view has to be updated
immediately; updates also have higher overhead if the key column of the index is affected by
the update.
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