SQL order of operations question

[noober]

Okay, please do not tease the dummy (me)...but does the way a SQL statements criteria filters are ordered affect its performance? For instance if I have 100 client with a sales_tot > 10000 does this:

select * from tbl_sales
where client_code = "0100"
and sales_tot > 10000

--run fast than this:

select * from tbl_sales
where sales_tot > 10000
and client_code = "0100"

Just wondering if since I am limiting the number of possible qulaifying returns based via the specific client ID if the first statement is better than the second? I am sure this is simple learned on the first day type stuff, but I sort of woke up one day needing to know SQL without ever really having any real training.

 

[olded]

Hi:

The question is what data types are sales_tot and client_code? Apparently they are int, smallint, or perhaps decimal. Using strings requires the engine to perform a string to decimal conversion which is less efficient. Also, if memeory serves me correctly, the conversion forces a full table scan so even if the column(s) are indexed, the index isn't used.

Regards,

Ed