Statistics
A collection of 51 issues
Optimizing Teradata SQL Queries by Avoiding Full Table Scans and Utilizing Secondary Indexes
Learn how to optimize your Teradata SQL performance by leveraging secondary indexes! Avoid full table scans by bypassing the COALESCE function in the WHERE clause.
Improving SQL Performance with Simple Query Rewrites: Dealing with Duplicates and Business Calendars
Understanding Teradata Statistics Histograms: How the Optimizer Estimates Cardinality for WHERE Conditions
Teradata Statistics Histograms - A Short Introduction
Many are familiar with the Optimizer's statistical confidence levels. I was recently surprised to discover that a "high confidence" rating does not guarantee a fully accurate estimation (provided the statistics collected are not stale). While I remain hopeful that
Layer and Preparatory Table Strategies
Typically, query tuning involves altering the composition of various objects.
An alternative method for achieving quicker results, in cases where modifying SQL, is not feasible or has already been completed, involves substituting the objects from which data is retrieved. By incorporating intermediate objects into a daily job chain, numerous queries
Collect Statistics in Teradata - Evaluation
How Teradata Optimizer Uses Multi-Column Statistics
SQL Tuning Goals: Improving Performance and Reducing Resource Usage
Learn about the goals of SQL tuning and how to optimize database performance by reducing resource usage. Skew, IOs, and CPU seconds are key metrics. Discover how to ensure completeness and correctness of Teradata statistics, detect missing and stale statistics, and improve query plans.
How to Simplify Database-to-Database Table Copying with Teradata Parallel Transporter (TPT) and tdload
The Teradata Parallel Transporter (TPT) is a Teradata Tools and Utilities (TTU) product. Teradata TPT offers under one roof an SQL-like scripting language that simplifies the syntax of old Teradata Utilities for handling external data (e.g., FastLoad, MultiLoad, TPump, BTEQ, and FastExport).
Copying Tables between Teradata Systems
A classic