Views and Path Filtering for CSV | Native Object Store ( NOS ) | Teradata Vantage - 17.00 - Using Views and Path Filtering - Teradata Database

Teradata Vantageā„¢ - Native Object Store Getting Started Guide

prodname
Advanced SQL Engine
Teradata Database
vrm_release
17.00
created_date
September 2020
category
Programming Reference
featnum
B035-1214-170K

There are specific benefits to creating foreign table views, in addition to the usual reasons of security and hiding SQL complexity. These benefits include:

  • Simplified payload attribute names. You can replace attributes named with dot notation with descriptive names.
  • Makes it easier to query object store data with inconsistent uppercase and lowercase field names. CSV field names are case sensitive, but Teradata SQL is case insensitive.
  • You can hide the $path references in a foreign table and make path names look like standard column names.

Follow these recommendations when creating a view on a foreign table:

  • Include both path names and payload attributes as columns in the view.
  • CAST all values in the view to an appropriate data type.
  • It is often the case that the path segment name (such as siteno in data / siteno / year / month / day) is also represented by an attribute in your data. When this is true, Teradata recommends you equate them in the WHERE expression in the view and only specify one of them in the column list. For example, see the use of TheSite in the example view here: Using a View with Path Filtering.