Efficient Retrieval of JSON Data | Native Object Store ( NOS ) | Teradata Vantage - 17.05 - Using Filtering to Retrieve JSON Data More Efficiently - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - Native Object Store Getting Started Guide

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
Release Date
January 2021
Content Type
Programming Reference
Publication ID
B035-1214-175K
Language
English (United States)

Reading all the objects in a bucket can be time-consuming and expensive. An alternative solution is to filter the object store using one or both of the following filtering methods:

Path Filtering
  • A path is a series of values that constitute a multi-level key (siteno, year, month, day) which identifies one or more objects within an object store.
  • Path filtering lets you pre-select which objects in the object store you want to bring back to the database, by providing specified values for different levels in a path key (for example, "WHERE $path.$siteno = '09380000'")
  • Path filtering is the most efficient way to read a selected portion on object store.
Payload Filtering
  • The payload column within a foreign table contains all of the values within an object.
  • When filtering is applied to attributes within a payload column ("WHERE payload.Flow > '15'"), all objects in the object store have to be brought inside the database and be transformed prior to applying filtering.
  • When given a choice, this is usually less efficient because it will incur greater effort at both the object store level and the database level than does path filtering.