Monthly Archives: November 2012

Tuning Time Series Metrics

In this post I am going to explore some performance issues related to OBI’s time series functions.  Released back in OBI 10g, the ToDate() and Ago() functions brought a significant improvement to the process of easily creating a variety of time series metrics.  In older versions of Siebel Analytics, creating time series was a very manual effort involving a lot of aliases and special joins that could at time become a little confusing to the developer.  They did have a wizard called the Time Series Wizard to assist, but if you are like me you never use wizards J.  The Time series functions however solved that; using them is a piece of cake, requiring only a minor enhancement to the Date dimension.

All is rosy with the world then, correct?  Well not so fast.  The reality is that these functions do some very strange things behind the scenes in order for them to work properly.  So strange in fact that the database engine typically has some difficulty figuring out what to do.  One thing I’ve learned over the years when it comes to database engine performance – keep it simple if you want it to run fast.

As it turns out these strange things that OBI does for the Time Series functions in fact cause a decent performance hit when compared with the old technique.  This short post will discuss this in more depth. Read the rest of this entry