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Performance Tuning

A collection of 267 issues

Optimizing Join and Aggregation with Teradata UNION ALL Views

Teradata 16 introduces a new option for handling sets of rows combined with "UNION ALL" in views and derived tables, reducing resource usage. The optimizer can apply aggregation steps and join operations to each branch of the "UNION ALL" separately, resulting in smaller spool sizes and improved perf

Understanding Soft Referential Integrity and Its Role in Improving Performance

Learn about referential integrity and how it ensures data consistency in databases. Discover soft referential integrity and its use in inner join elimination.

How to Optimize Joins in Teradata: A Case Study

Learn how to optimize joins in Teradata with this case study. Discover how simple changes in query text can improve query performance.

How to Use Biased Value Histograms for Accurate Statistics Estimation on Teradata SQL

Learn how biased value histograms store exact cardinalities and provide up-to-date statistics for queries, and witness how the Optimizer estimates the number of rows for a given query.

Improving Performance through Query Rewriting with Row Partition Elimination: A Real-World Optimization Example on a 400-Million-Row Table

Learn how query rewriting can improve performance in row partition elimination. Follow the test setup to optimize the retrieval of rows from a table.

How to Reduce Skew in Teradata Joins Using the RANDOM() Function

Natural skew may hinder join performance, but the PDPR capability in Teradata 14 can alleviate this problem. However, PDPR may not detect all potential applications if skewed values are not evident in the statistics. If your Teradata version is below 14, PDPR is unavailable. To address this, you can use

Understanding Workload Flow Control with DBC. ResUsageSAWT Table in Teradata 14.10 and Later Versions

Learn how to analyze workload in Teradata using the DBC.ResUsageSAWT table. This guide explores the essential columns and measures to consider.

Understanding Teradata Express Requests and How They Work with AMPs

Learn how express requests work in Teradata, bypassing stages like syntax checking and permission checking, and how Teradata 14.10 offers a new feature to expedite them.

Teradata Tuning Ideas: Best Practices and Strategies

Learn how to optimize Teradata performance with these general tuning ideas. From changing one parameter at a time to testing on the target system.

Practical Approach for Teradata SQL Tuning: Finding the Root Cause of Performance Issues

To optimize Teradata SQL performance, it is crucial to identify the root cause of any issues. The SQL statement itself is typically not the culprit but rather one or more stages of the execution plan. This article does not cover genuine optimization techniques. Instead, it presents a pragmatic method for