14 Redshift Data Types to make you the office hero
Redshift data types are not a whole lot different from the standard relational database types.
Relational Databases store data in tables, which are made up of rows and columns. A column is the smallest granularity of logical data storage. Each of these columns have attributes associated with it. A Redshift Data Type, in this context defines the attributes of a column.
There are 4 categories of built-in Redshift data types: Character, Numeric, Datetime and Boolean. Knowing these data types and their attributes is key to writing quality DDL statements in Redshift.
The tables below lists the types within each of these categories.
Related: Understand what Amazon Redshift is !
Character Redshift data types
CHAR
The important stuff:
- A VARCHAR in Redshift is a variable length character data type string with a maximum length of 65,535 bytes.
- VARCHAR, NVARCHAR, TEXT and CHARACTER VARYING are the same data types in Redshift
- You declare a VARCHAR data type as shown below
char(10) or character(10) or bpchar(10) or nchar(10)
Let us look at an example of creating a table in Redshift with the char data type. Since a char datatype uses up the entire allocated space, use char types for small fields. For larger character fields, use VARCHAR.
CREATE TABLE employees
(
marital_status char(1) default 'U'
);
VARCHAR
The important stuff:
- A VARCHAR in Redshift is a variable length character data type string with a maximum length of 65,535 bytes.
- VARCHAR, NVARCHAR, TEXT and CHARACTER VARYING are the same data types in Redshift
- You declare a VARCHAR data type as shown below
varchar(20)or nvarchar(10) or text(10) or character varying (10)
Below is an example of a redshift create table statement with two VARCHAR fields, first name and last name.
CREATE TABLE employees
(
first_name varchar(30),
last_name varchar(30)
);
Redshift Numeric data types
SMALLINT
The important stuff:
- A smallint can store upto 2 bytes of information.
- Use a Redshift smallint data type to store whole numbers in the range -32,768 to +32,767
- Syntax for a SMALLINT is
smallint or int2 INTEGER
The important stuff:
- Use the INTEGER data type in Redshift to store whole numbers in the range -2,147,483,648 to +2,147,483,647
- Syntax for an INTEGER is
integer or int or int4
BIGINT
The important stuff:
- If you need to store really large whole numbers in the range -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807, then use the Redshift BIGINT data type
- A bigint in Redshift can store upto 8 bytes of information.
- Syntax for a BIGINT is
bigint or int8 DECIMAL
The important stuff:
- If you need to store numbers with scale and precision, then use the DECIMAL data type
- DECIMAL uses up to 128 bytes to store numeric data as signed integers with a precision of up to 38 digits
- Syntax for a DECIMAL data type is
decimal(precision, scale) REAL
The important stuff:
- Use the REAL or FLOAT4 data type to store numbers with up to 6 digits of variable precision
- Syntax for a REAL data type is
real or float4 FLOAT
The important stuff:
- FLOAT stores numeric data with up to 15 digits of variable precision
- Syntax for a Redshift FLOAT data type is
float or float8 or double precision
DateTime Redshift data types
DATE
The important stuff:
- The DATE data type uses 4 bytes to store the Calendar date in the default format YYYY-MM-DD
- The date range goes from 4713 BC to 294276 AD
- Syntax for a DATE data type is as shown below
date
TIMESTAMP
The important stuff:
- TIMESTAMP uses 8 bytes to store date and time of day in default format YYYY-MM-DD HH:MI:SS
- This type does not include TIME ZONE
- Similar to the DATE data type, the range goes from 4713 BC to 294276 AD
- Syntax for a Redshift TIMESTAMP is
timestamp
TIME
The important stuff:
- TIME uses 8 bytes to store the time of day without the TIME ZONE
- For displaying time in a 24 hour clock format use HH24:MI:SS
- If you are displaying time in a 12 hour clock format, then use HH12:MI:SS
- Syntax for TIME is
time
TIMETZ
The important stuff:
- TIMETZ uses 8 bytes to store the time of day with the time zone
- Syntax for Redshift time of day with time zone is
timetz
TIMESTAMPTZ
The important stuff:
- To capture timestamp with the time zone, use TIMESTAMPTZ
- TIMESTAMPTZ uses 8 bytes to store data in the format YYYY-MM-DD HH:MI:SS TZ
- Syntax for a Redshift timestamp with time zone type is
timestamptz
Redshift Boolean Data Type
BOOLEAN
The important stuff:
- A Redshift boolean data type is a single byte column used to store true or false values.
- You can use ‘1’, ‘t’,’ y’, ‘yes’, ‘true’ or ‘TRUE’ to represent a True value in your input.
- False values can be represented as ‘0’, ‘f’, ‘n’, ‘no’, ‘false’ or ‘FALSE’ in the input.
- Unknowns are represented as NULL
- The syntax for a boolean data type in Redshift is
boolean
Redshift helpful links
Amazon Redshift Documentation
This is the latest version of Amazon Redshift Documentation
Amazon Redshift & Analytics
Another great blog post by Nick Corbett, AWS Professional Services on Agile Analytics with Amazon Redshift