Data Block Selectivity | Teradata Vantage - 17.10 - Data Block Selectivity - Advanced SQL Engine - Teradata Workload Management

Teradata Vantageā„¢ - Workload Management User Guide

Product
Advanced SQL Engine
Teradata Workload Management
Release Number
17.10
Release Date
July 2021
Content Type
Administration
User Guide
Publication ID
B035-1197-171K
Language
English (United States)

Use the data block selectivity criterion (the percentage of the table the request accesses) to give more resources to requests that access a small subset of the table. For example, you can send a request doing a full-table scan against a large table to a low-priority workload, and send a request accessing only one partition (1/200th of the table) to a high-priority workload.

Data block selectivity is particularly useful on large partitioned tables, but it is also useful for nonpartitioned tables.