Database Reference
In-Depth Information
5.
The result is the graphical estimated execution plan that is as follows:
--Query statistics
/*
(31921 row(s) affected)
Table 'TransactionHistoryArchive'. Scan count 1, logical reads
622, physical reads 0, read-ahead reads 0, lob logical reads 0,
lob physical reads 0, lob read-ahead reads 0.
*/
6. The default choice of query optimizer has to verify the existence of a
nonclustered
index on the conditional columns.
The optimizer has to choose either index on the
ModifiedDate
column to locate
required rows and then look up the corresponding through the clustered index.
7. But, in this case, the graphical execution plan confirms the Clustered Index
Scan
PK_TransactionHistoryArchive_TransactionID
and filters
out the unmatched rows.
8.
The query plan estimates the cost as 622 logical reads; one read per page of
the table.
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