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From Jeff Hammerbacher <ham...@cloudera.com>
Subject Re: switching to different parser in Pig
Date Sun, 15 Feb 2009 23:01:15 GMT
Hey,

Just chiming in to say that Hive uses ANTLR; Ashish (athusoo@facebook.com)
can provide more detailed feedback on their experiences with ANTLR.

Later,
Jeff

On Sat, Feb 14, 2009 at 5:16 AM, Ted Dunning <ted.dunning@gmail.com> wrote:

> Not even close.
>
> Take, for example,
>
> 1) the problem of using the output of a Pig query as the list of files used
> as input.
>
> 2) Or running some query in an iterative fashion until convergence is
> reached.
>
> 3) Or running a pig query, doing a matrix computation on the result and
> then
> running another pig query on the output of the matrix computation.
>
> You can do (1) by running a pig query using an external script and then
> downloading the output and expanding that into a pig using a template
> expansion and then executing that expanded template.
>
> You can do (2) by having an external script that runs a pig program over
> and
> over again, downloading the results and checking for convergence.
>
> You can do (3) by running one program, then downloading results, computing,
> uploading results and running another program.
>
> All of these are maintenance nightmares which would be greatly eased if
> pig's semantics could be glued nicely into a good scripting language.
> Having access to the AST's would make that pretty easy.
>
> On Sat, Feb 14, 2009 at 4:10 AM, pi song <pi.songs@gmail.com> wrote:
>
> > Due to my limited knowledge, I don't quite understand why building ast
> from
> > outside Pig would be helpful. Isn't Pig Latin already good enough to
> > interface to the world?
> >
>
>
>
> --
> Ted Dunning, CTO
> DeepDyve
> 4600 Bohannon Drive, Suite 220
> Menlo Park, CA 94025
> www.deepdyve.com
> 650-324-0110, ext. 738
> 858-414-0013 (m)
>

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