On 2018-02-10 16:13:04 +0100, Nicolas Paris wrote: > Hello > > I d'found useful to be able to import/export from postgres to those modern data > formats: > - avro (c writer=https://avro.apache.org/docs/1.8.2/api/c/index.html) > - parquet (c++ writer=https://github.com/apache/parquet-cpp) > - orc (all writers=https://github.com/apache/orc) > > Something like : > COPY table TO STDOUT ORC; > > Would be lovely. > > This would greatly enhance how postgres integrates in big-data ecosystem. > > Any thought ? So, I think making COPY extensible would be quite beneficial. I'm however quite doubtful that we want to add core code to handle all of the above. I think we should make the COPY input/output formatting extensible by extensions. I think we'd have something like CREATE COPY HANDLER name HANDLER somefunction; somefunction would have to be a function that returns type pg_copy_handler, which in turn basically is a struct of function pointers. I imagine we'd have callbacks for - start copy in / out - output row, with a an array of values/nulls - parse row, with a input buffer as argument, returning values / nulls arrays - finish copy in / out we'd also need to expose a few more utility functions from copy.c externally. I think this'd require a good bit of cleanup in copy.c... Greetings, Andres Freund
