The Database.executeBatch method takes an optional parameter scope. This parameter specifies the number of records that should be passed into the execute method.

Syntax:


Database.executeBatch(instance of batch class,scope);

Sample:

AccountUpdate au = new AccountUpdate();
Database.executeBatch(au,1500);

The limit for scope parameter is 2000.

The default value is 200.

If the scope value is greater than 2000, it will consider as 2000 and then process.