问题
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'
?
回答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.
回答2:
if you had only one of the two to search with, which would it be? list that first
来源：https://stackoverflow.com/questions/797830/how-to-order-fields-on-index-creation-sql-server-2005