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.