Warning: Teradata 16.20 Upgrade May Affect Reporting Queries - Potential Fix Found
There are some important considerations to keep in mind when upgrading to Teradata 16.20.
After upgrading to Teradata 16.20, we noticed that certain reporting queries produced inconsistent result sets upon each execution. Occasionally, the results were accurate, while at other times they were inaccurate.
Upon analysis, I found a correlation between Incremental Planning and Execution (IPE). When this function is enabled, the execution plan may encounter errors. I will conduct additional research and provide an update regarding this matter. It is possible that a patch has already been released. Your feedback is welcome.
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Ever since disabling this feature, my result sets have been consistently accurate. To ensure this remains the case until a resolution is found, I am implementing the following query band as a pre-SQL step on every Microstrategy report.
SET QUERY_BAND = ‘DynamicPlan=OFF;’ FOR SESSION;This information could be helpful to those encountering this issue.
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Written by Roland Wenzlofsky, founder of DWHPro and author of Teradata Query Performance Tuning. DWHPro has helped data warehouse practitioners for 15+ years.