Min/Max functions do not work for firstn() and lastn() aggregation

Min/Max functions do not work for firstn() and lastn() aggregation

book

Article ID: KB0079223

calendar_today

Updated On:

Products Versions
TIBCO Streaming 7.7

Description

I want to obtain the maximum or minimum last N values from a list in an aggregate context.  For example.. 

max(lastn(4, MyField))
..produces a typecheck error in Studio ("not a valid aggregate expression").

Resolution

These errors occur because max() and min() functions cannot accept lists as input arguments.  Instead, use maxelement().. 
maxelement(lastn(4, MyField))

 

Issue/Introduction

Min/Max functions do not work for firstn() and lastn() aggregation

Additional Information

For reference, our List-related functions are noted in the Help under StreamBase Home > StreamBase References > StreamBase Expression Language Functions > (sub-heading) Simple Functions: Lists:

https://docs.tibco.com/pub/sb-cep/7.7.3/doc/html/reference/expressions.html
Powered by Wolken Software