SQL Server operands order

Question

If there is a very large table T1(Id INT, Name VARCHAR(MAX), Category VARCHAR(MAX)) and Category is INDEX UNIQUE NONCLUSTERED, does it matter the order of operands if I do the select like

SELECT * FROM T1 WHERE Name = 'name' and Category = 'cat'

vs

SELECT * FROM T1 WHERE Category = 'cat' and Name = 'name'

?

You have a unique non-clustered index on a VARCHAR(MAX)? Really? — Frank Fajardo, Feb 02 '16 at 18:29
@roryap: In the test environment no difference since the table is not large. I can't create a large table due my access level. I'm concern about the production very large table. — kord, Feb 02 '16 at 18:29

score 1 · Accepted Answer · answered Feb 02 '16 at 18:28

1

Theres isnt any difference, you db planner will parse the code and choose the better option.

What is interesting is the order of execution can change if table sizes change. But how you write it wont.

answered Feb 02 '16 at 18:28

Juan Carlos Oropeza

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score 0 · Answer 2 · answered Feb 02 '16 at 18:26

0

There might be a difference based on which indexes you have on the table. Check actual execution plan to see what sql decides to use

answered Feb 02 '16 at 18:26

vittore

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SQL Server operands order

2 Answers2