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
