Did you mean that you are doing a select to find a single column? What you typed was row, but that seems out of line with the rest of what you wrote.
If you are truly asking about filtering down to a single row, whether it costs more to return all of the columns rather than just one from a single row will depend on whether Drill is extracting columns before filtering or after. On Mon, Apr 11, 2016 at 6:41 AM, Johannes Zillmann <[email protected] > wrote: > Hey there, > > i currently doing some performance measurements on Drill. > In my case its a single parquet file with a single local Drill Bit. > > Now in one case i have unexpected results and i’m curious if somebody has > a good explanation for it! > > So i have a file with 10 mio rows with 9 columns . > Now i’m doing a select statement to find one single row. > Runtime with select * : ~ 14.79 s > Runtime with select(filterField) : ~ 1.5 sec > > So i’m surprised that there is so much variance depending on the fields i > select, since i thought Drill needs most time for finding that one element, > and then deserialize the other fields only on a hit… > But for deserialising 8 more hits 10 sec seem way to much!?!?!? > > best > Johannes > >
