how to represent and optimize a query over partitioned storage

[Константин Новиков]

Hi,
 
Given some partitioned storage, we can omit the scan of some partitions when a 
filter is present. How can the lower cost of the scan be represented? As far as 
I can tell the current approach only allows providing a single cost for the 
TableScan and Filter can only add to that. Should my implementation provide a 
rule that combines Filter+TableScan?