Creating Column Families

A Cassandra Column Family is similar to a table in a relational database management system. However, unlike relational tables, Column Families only define metadata of the columns as described below when creating a Column Family. The actual columns in a row are defined typically by the client application. The actual columns of each row can vary from each other depending on the data stored in a row.

Follow the steps below to add column families to an existing keyspace. Also see, Creating Keyspaces.

1. Click List under Cassandra Keyspaces and select a keyspace to add column families to.
   

2. Click Add a New Column Family to open the New Column Family window where you can enter column family details to the keyspace.
   
   
   The fields of the new column family window are described below:

   Fields	Description
   Name*	Column Family (CF) Name is mandatory. Must not contain the character "-".
   Comment	Description of the column family. Used to attach additional human-readable information about the column family to its definition
   Column Type	Standard Column Family Super Column Family
   Key Validation Class	Datatype of Row keys
   Comparator	Datatype of Column keys
   Default Validation Class	Default datatype of Column values

3. Click Save after adding column family details. The Keyspace Information window opens with links to column family operations such as Set Permissions, edit or delete.
   

4. Click on the Column Family's name and then the Add New Index/Non-Index Column link to create an indexed or non-indexed column.

   

   Field	Description	Required/Optional
   Name	Name of the new column	Required
   Index Name	Index Name	Required (only in case of an index column)
   Validation Class	Datatype of column value	Required

   There are 2 ways of defining a column. 

   1) Create a (non-indexed) column with a Validation class: Do not specify any values for 'Index Name'.

   2) Create an indexed column with a Validation class: Specify a name for the Index in 'Index Name'.