Hey Larry, Drill transforms your CSV data into an internal memory-resident format for processing, but does not change the structure of your original data.
If you want to convert your file to parquet, you can do this: create table `foo.parquet` as select * from `foo.csv` This will, however, not leave you with interesting column names. You can add names inside the select or by putting a parenthesized list of fields after the word 'table'. Often you will want to add casts in the select to indicate what type of data you want to use. On Thu, Jul 2, 2015 at 12:48 PM, Larry White <ljw1...@gmail.com> wrote: > hi, > > i'm using drill to provide a query-able wrapper around some csv files. when > i load a csv datasource, is the data transformed in someway (beyond what > Calcite does) to improve performance? Specifically, is it transformed into > column format? re-written as parquet, or otherwise optimized? > > thanks. > > larry >
