Performance Diagnostic Methodology

Performance Diagnostic Method and Tools is targeted to uncover and resolve performance related issues in three primary areas...

1. Costly SQL Operations --- this will go beyond finding and resolving the “Killer Query”  and the highly skewed queries which are quite easy to identify.  Focus on finding  costly scripts and repeating patterns which tend to have lots of smaller operations well below the radar of the traditional performance tuning effort.
    
2. Excessive Statistics Collection ---  Statistics collection is very important in that it gives the optimizer critical demographic information with which to build efficient join plans.  But statistics collection has a cost and it can be easily overdone.  There are some systems where over 20% of the resources are consumed in statistics collection.  Add the cost of ETL and there isn’t very much system left to perform analytic work.  A reasonable target is five to ten percent.
    
3. Index and Partition Tuning  --- it is a well-known fact that Teradata is extremely effective at doing full table scans and other that the Primary Index needed for data distribution is not overly dependent on indexes.  What is less known is that Teradata has a full suite of index options which can be effective to improve efficiency and performance.   The methods and tools shown here have proven helpful in identifying where index efforts should be focused.

Presenter: Arnie VanWyk