The other big missing bit is that the working variables can't be complex data.
That means that I can't write: - my own form of count unique - approximate aggregates like hyper-log-log, tdigest - anything that constructs complex output like list_aggregate This is just as bad as the lack of two-phased aggregate. On Wed, Sep 23, 2015 at 12:00 PM, Jacques Nadeau <[email protected]> wrote: > Merging is the main missing thing. Drill supports building custom aggregate > functions. However, those are currently run in a single thread per > grouping. Generally, it is much better to do a two-phased aggregate for > custom functions, however the interface doesn't yet support that > functionality. > > -- > Jacques Nadeau > CTO and Co-Founder, Dremio > > On Wed, Sep 23, 2015 at 10:36 AM, Neeraja Rentachintala < > [email protected]> wrote: > > > https://drill.apache.org/docs/developing-an-aggregate-function/ > > See the customer aggregate functions are marked as alpha and experimental > > usage only. > > What features or aspects are missing to make this a 'ready to deploy in > > production' capability. > > Appreciate response. > > > > thanks > > -Neeraja > > >
