The number of characters or bytes Database Engine 20 exports can exceed or be less than the number of characters or bytes the client application expects to receive unless the export width is set properly.
The export width defines how the system reserves space for each character field in result set rows returned to Teradata clients.
64000 bytes is the maximum possible for an exported character string.
Export Width Rules
The character conversion parameters for all export width definitions are stored as a rule set in the DBC.ExportWidth table, for example:
SELECT * FROM DBC.ExportWidth;
ExportDefinitionName ExportWidthRuleSet -------------------- ----------------------------------------- EXPECTED 1112211111222232222211121111112222322222 MAXIMUM 1322323221332232322321123111122322323222 COMPATIBILITY 1112211111111231111111121111112222322222 CustomDefinition1 4112211111222232222211121111112222322224
Export Width Space Considerations
The export width value is a multiplier, so that if data in the server character set is n bytes, and the export width is 2, the same data in the result set occupies 2n bytes.