How to Add a Column in Redshift

Adding a column in Redshift involves using the ALTER TABLE command. The typical syntax is as follows:

ALTER TABLE promotions ADD expiry_date DATE;

Redshift supports the following data types:

  • SMALLINT (INT2)
  • INTEGER (INT, INT4)
  • BIGINT (INT8)
  • DECIMAL (NUMERIC)
  • REAL (FLOAT4)
  • DOUBLE PRECISION (FLOAT8)
  • BOOLEAN (BOOL)
  • CHAR (CHARACTER)
  • VARCHAR (CHARACTER VARYING)
  • DATE
  • TIMESTAMP

Here’s an example of adding a string (varchar) column with a not null constraint:

ALTER TABLE users ADD nickname VARCHAR NOT NULL;

Adding a boolean column with a default value:

ALTER TABLE users ADD active BOOLEAN DEFAULT TRUE;