Question

As this article‘s figure 4 says, SQL Server 2005 + can return you a list of missing indexes. It stores 2 important info about missing indexes:

[EqualityUsage],[InequalityUsage]

If I have a missing index where:

[EqualityUsage]=’col1′,[InequalityUsage]=’col2′

Should I create an index with Indexed Key Columns:

‘col1,col2’

or

‘col2,col1’

?

Answer 1

col1, col2

CREATE INDEX

To convert the information returned by
sys.dm_db_missing_index_details into a
CREATE INDEX statement, equality
columns should be put before the
inequality columns, and together they
should make the key of the index.
Included columns should be added to
the CREATE INDEX statement using the
INCLUDE clause.