Hey Milinda, Are you referring to this thread?
http://mail-archives.apache.org/mod_mbox/incubator-calcite-dev/201502.mbox/%3CCACwebjTshFNi=es4qz1zkkqmuygzn+lwj_bapqpdrvsy2tq...@mail.gmail.com%3E It appears as though your question remains unanswered. :( > If we consider LogicalFilter as a relation operator, we need something to > convert input stream to a relation before sending the tuples downstream. Does CQL model this as a window operator where every window is exactly 1 row (i.e. a sliding window of length 1)? Cheers, Chris On Thu, Feb 26, 2015 at 12:18 PM, Milinda Pathirage <mpath...@umail.iu.edu> wrote: > Hi devs, > > I ask about $subject in calcite-dev. You can find the archived discussion > at [1]. I think your thoughts are also valuable in this discussion in > calcite list. > > I discovered the requirement for a default window operator when I tried to > integrate streamscan (I was using tablescan prevously) into the physical > plan generation logic. Because of the way we have written the > OperatorRouter API, we always need a stream-to-relation operator at the > input. But Calcite generates a query plan like following: > > LogicalDelta > LogicalProject(id=[$0], product=[$1], quantity=[$2]) > LogicalFilter(condition=[>($2, 5)]) > > StreamScan(table=[[KAFKA, ORDERS]], fields=[[0, 1, 2]]) > > If we consider LogicalFilter as a relation operator, we need something to > convert input stream to a relation before sending the tuples downstream. > In addition to this, there is a optimization where we consider filter > operator as a tuple operator and have it between StreamScan and > stream-to-relation operator as a way of reducing the amount of messages > going downstream. > > Other scenario is windowed aggregates. Currently window spec is attached to > the LogicalProject in query plan like following: > > LogicalProject(EXPR$0=[CASE(>(COUNT($2) OVER (ROWS BETWEEN 2 PRECEDING AND > 2 FOLLOWING), 0), CAST($SUM0($2) OVER (ROWS BETWEEN 2 PRECEDING AND 2 > FOLLOWING)):INTEGER, null)]) > > I wanted to know from them whether it is possible to move window operation > just after the stream scan, so that it is compatible with our operator > layer. > May be there are better or easier ways to do this. So your comments are > always welcome. > > Thanks > Milinda > > > [1] > > http://mail-archives.apache.org/mod_mbox/incubator-calcite-dev/201502.mbox/browser > > -- > Milinda Pathirage > > PhD Student | Research Assistant > School of Informatics and Computing | Data to Insight Center > Indiana University > > twitter: milindalakmal > skype: milinda.pathirage > blog: http://milinda.pathirage.org >
