The syntax for defining LOB data, either as BLOB or CLOB, in a Teradata PT schema is shown below:
- BLOB (lengthBytes) or CLOB (lengthBytes)
This syntax indicates that the Teradata PT load or extract job will use the inline method to transfer the LOB data between the Teradata PT and Teradata Database.
- BLOB (lengthBytes) AS DEFERRED BY NAME or CLOB (lengthBytes) AS DEFERRED BY NAME
This syntax indicates that the LOB data is transferred using the deferred method.
When LOB columns are defined as DEFERRED BY NAME in the schema, Teradata PT expects regular VARCHARs in place of deferred LOB columns in a data row. Each VARCHAR is a file name of a flat file that contains the actual data for a deferred LOB column. Teradata PT refers to these VARCHARs as LOB file locators.