Schema hints override inferred target column data types. Teradata recommends schema hints in the following situations:
| Situation | Where to Use Schema Hints |
|---|---|
| Flow created a target table that does not meet your expectations. | Use schema hints for columns that did not map as expected. For example, if Flow infers VARCHAR(134) but the column value can exceed 134 characters, use a schema hint to specify VARCHAR(200). |
| You know exactly how you want to map your input data to the target table. | Use a schema hint for every column. |
| You specify an existing target table. | Use schema hints for columns whose types differ from those that Flow infers (see Schema Inference). This practice helps prevent load errors. |
Specify schema hints in load directives, which are in . Enter the column names and types. For example:
| column name: | type: |
|---|---|
| ticket_cost_usd | DECIMAL(4,2) |
| showing_time | TIME(0) |
| movie_release_date | DATE FORMAT 'YY-MM-DD' |