Best Practices for Using Native Object Store | NOS | Teradata Vantage - 17.10 - Best Practices for Using NOS - Advanced SQL Engine - Teradata Database
Teradata Vantage™ - Native Object Store Getting Started Guide
- Product
- Advanced SQL Engine
- Teradata Database
- Release Number
- 17.10
- Release Date
- July 2021
- Content Type
- Programming Reference
- Publication ID
- B035-1214-171K
- Language
- English (United States)
- You can use READ_NOS to ascertain whether headers are present.
- To reduce the volume of data processed in the Advanced SQL Engine, either specify a more specific LOCATION string in the USING clause of the foreign table definition or use PATHPATTERN variables in the SQL statement.
- To ensure that path filtering is applied consistently, Teradata recommends that the database administrator capture path filtering (with appropriate casting of column data types) in a view of the foreign table and make the view available to end users.
- To improve performance of SQL statements with GROUP BY or ORDER BY clauses that include JSON files, cast values from their default VARCHAR data type to narrower data types.
- When joining a foreign table to either a relational table or another foreign table, collect statistics on the payload attribute that is used as a join constraint.
- If you generate spool tables, the spool is smaller if you cast values to narrower data types.