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From DB Tsai <>
Subject Re: [VOTE][SPARK-27396] SPIP: Public APIs for extended Columnar Processing Support
Date Sat, 25 May 2019 00:03:24 GMT
+1 on exposing the APIs for columnar processing support.

I understand that the scope of this SPIP doesn't cover AI / ML
use-cases. But I saw a good performance gain when I converted data
from rows to columns to leverage on SIMD architectures in a POC ML

With the exposed columnar processing support, I can imagine that the
heavy lifting parts of ML applications (such as computing the
objective functions) can be written as columnar expressions that
leverage on SIMD architectures to get a good speedup.


DB Tsai
PGP Key ID: 42E5B25A8F7A82C1

On Wed, May 15, 2019 at 2:59 PM Bobby Evans <> wrote:
> It would allow for the columnar processing to be extended through the shuffle.  So if
I were doing say an FPGA accelerated extension it could replace the ShuffleExechangeExec with
one that can take a ColumnarBatch as input instead of a Row. The extended version of the ShuffleExchangeExec
could then do the partitioning on the incoming batch and instead of producing a ShuffleRowRDD
for the exchange they could produce something like a ShuffleBatchRDD that would let the serializing
and deserializing happen in a column based format for a faster exchange, assuming that columnar
processing is also happening after the exchange. This is just like providing a columnar version
of any other catalyst operator, except in this case it is a bit more complex of an operator.
> On Wed, May 15, 2019 at 12:15 PM Imran Rashid <> wrote:
>> sorry I am late to the discussion here -- the jira mentions using this extensions
for dealing with shuffles, can you explain that part?  I don't see how you would use this
to change shuffle behavior at all.
>> On Tue, May 14, 2019 at 10:59 AM Thomas graves <> wrote:
>>> Thanks for replying, I'll extend the vote til May 26th to allow your
>>> and other people feedback who haven't had time to look at it.
>>> Tom
>>> On Mon, May 13, 2019 at 4:43 PM Holden Karau <> wrote:
>>> >
>>> > I’d like to ask this vote period to be extended, I’m interested but
I don’t have the cycles to review it in detail and make an informed vote until the 25th.
>>> >
>>> > On Tue, May 14, 2019 at 1:49 AM Xiangrui Meng <>
>>> >>
>>> >> My vote is 0. Since the updated SPIP focuses on ETL use cases, I don't
feel strongly about it. I would still suggest doing the following:
>>> >>
>>> >> 1. Link the POC mentioned in Q4. So people can verify the POC result.
>>> >> 2. List public APIs we plan to expose in Appendix A. I did a quick check.
Beside ColumnarBatch and ColumnarVector, we also need to make the following public. People
who are familiar with SQL internals should help assess the risk.
>>> >> * ColumnarArray
>>> >> * ColumnarMap
>>> >> * unsafe.types.CaledarInterval
>>> >> * ColumnarRow
>>> >> * UTF8String
>>> >> * ArrayData
>>> >> * ...
>>> >> 3. I still feel using Pandas UDF as the mid-term success doesn't match
the purpose of this SPIP. It does make some code cleaner. But I guess for ETL use cases, it
won't bring much value.
>>> >>
>>> > --
>>> > Twitter:
>>> > Books (Learning Spark, High Performance Spark, etc.):
>>> > YouTube Live Streams:
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