Does the order of columns in a select statement affect query speed?

Question

For example, I have a database like this:

id | fname | lname | sex | age | tel | cell | address

If I do select cell, fname, address, sex instead of doing select fname, sex, cell, address, will that affect the speed of query, in big tables?

I did a quick check in phpmyadmin and it appeared to be taking same time, but I wanted to double check.

Thanks.

score 9 · Accepted Answer · answered May 26 '11 at 20:30

9

That won't make any difference.

However, omitting columns from the SELECT clause will make it run faster since it'll send less data over the network.

answered May 26 '11 at 20:30

SLaks

8

@Blue: Omitting columns that you are going to use will also make it faster. (As will omitting the entire query) – SLaks May 26 '11 at 20:35
Didn't he mean omitting the columns and just select all (*) ? – mowgli Aug 01 '14 at 07:58
1

@mowgli: No; that will make it slower (since it will need to send more data) – SLaks Aug 01 '14 at 12:30

score 1 · Answer 2 · answered May 26 '11 at 20:30

1

It won't affect it the slightest bit.

answered May 26 '11 at 20:30

Denis de Bernardy

score 1 · Answer 3 · answered May 26 '11 at 21:08

1

Another thing that will make it run faster is creating indexes on the fields that you will be searching the most.

answered May 26 '11 at 21:08

1

Searching means in the `WHERE` (or `ORDER BY`) clause. – SLaks May 26 '11 at 21:13
@SLaks, sorry, you are right, this should have been a comment. – May 26 '11 at 21:16

3 Answers3