What is faster SELECT * or SELECT `field` when only" field "is required

Question

I don’t want to assume here, I have already been bitten / proved.

Any help would be appreciated

Answer 1

The SELECT field is faster than select *.

Because if your table has more than 1 field / column, then select *, it will return all of them, and this requires network bandwidth and more work for the database to retrieve all other fields. But if you only need one field / column, the database load will be less and it will not need to transfer unnecessary information and, therefore, it is unsafe to use bandwidth resources.

Answer 2

@AntionoP SELECT field , , MySQL , .

Answer 3

Select * , select <field list>, * .
, ( ), ?

Answer 4

* , , blob. , .

Answer 5

• SELECT * (ALL) MySQL
• , select *

Answer 6

mysql, , "SELECT" . ?

Linux:

time (echo "SELECT * FROM table" | mysql -u username --password=passwd database > /dev/null)

time (echo "SELECT field FROM table" | mysql -u username --password=passwd database > /dev/null)

Answer 7

SELECT * , . . MySQL? , SELECT * , , EXPLAIN (..query..).

However, the easiest way to be sure is to simply not use it SELECT *in production requests.