Running Same Report Can Output Slightly Different Data

Products

• CA Infrastructure Management
• CA Performance Management - Usage and Administration

Issue/Introduction

Reports for metrics such as 95th percentile are showing very small  (.01 difference) when run repeatedly

Environment

Release :

Component : IM Reporting / Admin / Configuration

Cause

The functionality of the Vertica APPROXIMATE_PERCENTILE function

https://www.vertica.com/blog/database-approximate-median-percentile-functions/

Resolution

You can see small variances in the data due to the use of the APPROXIMATE_PERCENTILE function in the percentile queries.