Just curious...How can a column have multiple origins? Join key type scenarios where they have the same value regardless of where they originate from?
On Feb 19, 2017 09:18, "[email protected]" < [email protected]> wrote: > You can often get the original of a column via > RelMetadataQuery.getColumnOrigin(), > but keep in mind columns can have multiple origins or no origin at all. > > > On Feb 18, 2017, at 5:47 PM, barry squire <[email protected]> wrote: > > > > Hi everyone, > > > > Calcite's SQL parsing, planning and execution using the enumerators > module > > looks like a pretty good fit for an application I want to develop. > However, > > I have one requirement that I'd really appreciate some guidance on. > > > > Given an SQL query, I'm looking for a way to trace the lineage of a row > > from source tables, through each operator and eventually to the results. > > This is so I can produce something similar to pig illustrate ( > > http://research.yahoo.com/files/paper_5.pdf). > > > > I'm still very new to Calcite, but if I understand it correctly, I think > > could modify the BlockStatement that is generated in each > > Enumerator.implement function to track lineage between input and output > > rows. This doesn't seem wise though as it would lead to a custom fork > that > > I'd need to maintain. > > > > Can anyone provide some insight into the best way to approach this > problem? > > > > Thanks >
