How are data types defined in Teradata?

In Teradata, data types are defined at the time of table creation. This is a crucial step because defining the correct data types for each column in a table influences how data is stored, validated, and manipulated within the database system. During table creation, the database administrator or developer specifies the data type of each column, which could include types such as INTEGER, VARCHAR, DATE, and many others. This ensures that the data conforms to expected formats and optimizes storage and performance.

Setting data types at this stage helps enforce data integrity and provides clarity on what kind of data can be stored in each column. It also allows the Teradata database engine to allocate the appropriate amount of storage space and apply relevant processing efficiencies.

Defining data types during data entry, at the time of deployment, or during data migration would not establish a permanent definition of what data type a column should be, and these processes do not inherently create or enforce data structures in the database like table creation does. Therefore, the correct practice in Teradata is to define data types when creating the table.