Teradata

Teradata is a relational database management system.

Configure the following details for Teradata data source:

Register data source
Field	Description
Display name	Enter the data source name to be displayed on the screen.
Database name	Enter the name of your database.
Hostname	Enter the hostname.
Port	Enter the port number.
Authentication type	Choose and enter the Authentication type details. TD2: Enter the username and password. LDAP: Enter the username and password.
Port is SSL enabled	Use the toggle switch to enable or disable SSL connection. If enabled, i. The Upload SSL certificate (.pem, .crt, .cert or .cer) link is enabled. ii. Click the Upload SSL certificate (.pem, .crt, .cert or .cer) link. iii. Browse the SSL certificate and upload.
Test connection	Click the Test connection link to test the data source connection. If the data source connection is successful, a success message appears.
Catalog name	Enter the name of the catalog. This catalog is automatically associated with your data source.
Create	Click Create to create the data source.

Limitations for SQL statements

Only ADD COLUMN and DROP COLUMN are supported for ALTER TABLE statement. DROP COLUMN does not drop the first column.
DROP TABLE statement is supported only when enabled in the catalog.

BLOB and CLOB data types support only SELECT and CREATE statements.
The data that is shown from the UI for BLOB data type is in Base64 format, while the result from presto-cli is in hexadecimal format.
BINARY data type supports only SELECT statement.
VARBYTE is the BINARY alternative data type.
When the fields of data type REAL have 6 digits or more in the decimal part with the digits being predominately zero, the values when queried are rounded off. It is observed that the rounding off occurs differently based on the precision of the values. For example, a decimal number 1.654 when rounded to 3-digits after the decimal point are the same. Another example is 10.890009 and 10.89000. It is noticed that 10.89000 is rounded to 10.89, whereas 10.89009 is not rounded off. This is an inherent issue because of the representational limitations of binary floating point formats. This might have a significant impact when querying involves sorting.