Is SELECT * faster than 40 columns listing in MySQL?

The SELECT * is slower than 40 columns listing. It’s a better choice to list the column names while using the SELECT query. Let us see a simple example and create a table −

mysql> create table DemoTable(
   Id int,
   Name varchar(20),
   Age int,
   ZipCode varchar(20),
   CountryName varchar(20)
);
Query OK, 0 rows affected (0.82 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values(101,'Chris',23,'0909332','US');
Query OK, 1 row affected (0.48 sec)
mysql> insert into DemoTable values(102,'Bob',24,'8747443','AUS');
Query OK, 1 row affected (0.50 sec)
mysql> insert into DemoTable values(103,'Adam',21,'9988833','UK');
Query OK, 1 row affected (0.11 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+------+-------+------+---------+-------------+
| Id   | Name  | Age  | ZipCode | CountryName |
+------+-------+------+---------+-------------+
| 101  | Chris | 23   | 0909332 | US          |
| 102  | Bob   | 24   | 8747443 | AUS         |
| 103  | Adam  | 21   | 9988833 | UK          |
+------+-------+------+---------+-------------+
3 rows in set (0.00 sec)

Now, we will list every column name while using MySQL SELECT since it is considered a faster approach −

mysql> select Id,Name,Age,ZipCode,CountryName from DemoTable;

This will produce the following output −

+------+-------+------+---------+-------------+
| Id   | Name  | Age  | ZipCode | CountryName |
+------+-------+------+---------+-------------+
| 101  | Chris | 23   | 0909332 | US          |
| 102  | Bob   | 24   | 8747443 | AUS         |
| 103  | Adam  | 21   | 9988833 | UK          |
+------+-------+------+---------+-------------+
3 rows in set (0.00 sec)

AmitDiwan

Updated on: 27-Sep-2019

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