External tables
Netezza environments also support system tables, which are stored on the host, and user tables, which are stored on the disks in the storage arrays.
You can use external tables to load data into an IBM Netezza appliance or store data outside an IBM Netezza appliance. If you use an external table to store data outside an appliance, you can transfer the data to another application or use the data as a table backup. You can also use data from an external table as part of an SQL query.
An external table has a definition, also called a table schema, but the actual data exists outside the Netezza appliance database. After you create the external table definition, you can use INSERT INTO statements to load data from the external file into a database table or use SELECT FROM statements to query the external table.