I am trying to understand the motivation to not write anything to disk when we do a CTAS with a LIMIT 0 query.
And how will Drill treat an empty parquet file (one that has just the metadata and no actual data in it) that was generated by some external tool ? Today we return an Exception for such a case, in the future do we plan to handle this case and return (0 records or say no rows found) ? Thanks, Khurram On Fri, Mar 18, 2016 at 10:38 AM, Abdel Hakim Deneche <[email protected] > wrote: > Drill used to create such empty parquet files, but we would get an > exception when we try to query them (DRILL-3635 > <https://issues.apache.org/jira/browse/DRILL-3635>). > > Drill's current behavior when you do a CTAS with a LIMIT 0 query is to not > write anything to disk, then when you try to query the table you would get > a "table not found" error message. > > On Fri, Mar 18, 2016 at 2:53 AM, Khurram Faraaz <[email protected]> > wrote: > > > Hello All, > > > > Currently in Drill 1.7.0 we do not support, > > - the creation of empty parquet files. > > - and we see an Exception when empty parquet file is queried using > Drill > > > > Should we support the creation of empty parquet file that just has the > > metadata information in the parquet footer and no actual data (consider > the > > CTAS case that uses a LIMIT 0 query) > > > > Once such an empty parquet file is created, Drill should also be able to > > query that parquet file, and report to user that there are no rows to > > return. > > > > Thanks, > > Khurram > > > > > > -- > > Abdelhakim Deneche > > Software Engineer > > <http://www.mapr.com/> > > > Now Available - Free Hadoop On-Demand Training > < > http://www.mapr.com/training?utm_source=Email&utm_medium=Signature&utm_campaign=Free%20available > > >
