Columns are the small unity of a table and they define how data must be stored through their data types and additional attributes as shown in the image below.
||This attribute handles the data type assigned to the column.|
||This field defines the default value for the column in case of none is specified in a
The attribute Sequence is used to configure a default value for serial data types based upon a sequence object. Once selected the sequence this object will be converted into an expression like:
The Identity attribute is used to configure an identity column (introduced in PostgreSQL 10). The possible values of this field are
||Creates a NOT NULL constraint in the column.|
** Identity/Generated columns **