StateMap operator

Performs a mapping of incoming attributes to out-coming attributes using map functions. Odysseus also provides a wide range of mapping functions.

Hint: StateMap can use history information. To access the last n.th version of an attribute use "__last_n." Mind the two "_" at the beginning!

Parameter

• expressions: A list of expressions to map multiple incoming attribute values to out-coming attributes. Optional each expression can have a name (in this case use ['expression', 'expressionName'])
• group_by: An optional list of attributes over which the grouping should occur.

Example

output = STATEMAP({
              expressions = ['auction_id * 5','sqrt(auction_id)', '__last_5.auction_id]
             }, input)