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From Josh Wills <josh.wi...@gmail.com>
Subject Re: Best Practice for Materialization
Date Wed, 24 Feb 2016 20:20:35 GMT
Turn the PCollection into a ReadableData object, which is serializable and
can be passed into a DoFn and read in during initialization for use during
processing. That's how the MapsideJoin stuff is implemented.
On Wed, Feb 24, 2016 at 12:19 PM Micah Whitacre <mkwhitacre@gmail.com>
wrote:

> How do you need the data in the DoFn?  One easy way of doing this might be
> a MapSideJoin[1] but that would probably require similar keys for what you
> are doing with the data and might not fit with adding supplementary data in
> the DoFn like you are intending.
>
> [1] - http://crunch.apache.org/user-guide.html#mapjoin
>
> On Wed, Feb 24, 2016 at 2:04 PM, Robinson, Landon - Landon <
> landon.t.robinson@lowes.com> wrote:
>
>> Crunch Gurus,
>>
>> Say I have a small data set of key/value pairs I’m reading into a
>> Pcollection. I want to give that small set as a supplementary data set to
>> DoFns for comparisons.
>> I’ve done this before with hardcoded String arrays and such, but wanted
>> to know what best practice is for taking the contents of a very small
>> Pcollection, and handing it as an object to a DoFn.
>>
>> I know I can turn it into a Hashmap and pass it as an argument/param, but
>> is there a recommended way in Crunch? Thanks!
>>
>> ---------------------------------------------------------------------------
>> Landon Robinson
>> Big Data & Hadoop Engineer
>> IT Business Intelligence, Lowe’s Companies Inc.
>>
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