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From Paul Davis <paul.joseph.da...@gmail.com>
Subject Re: View Intersections
Date Sat, 11 Apr 2009 16:58:32 GMT
On Fri, Apr 10, 2009 at 11:31 PM, kowsik <kowsik@gmail.com> wrote:
> Parallel == multiple-threads across multiple-machines in the cluster? :-)
>
> By definition, temp views don't have no disk IO. It's map/reduce
> parallelized in memory directly served back over a TCP socket. Is that
> still not going to be fast enough?
>

Even temp views are written to disk.

> K.
>
> On Fri, Apr 10, 2009 at 7:26 PM, Paul Davis <paul.joseph.davis@gmail.com> wrote:
>> On Fri, Apr 10, 2009 at 8:51 PM, kowsik <kowsik@gmail.com> wrote:
>>> IMHO, the need for view intersections will go away once we have
>>> parallel map/reduce to the point where _temp_views's are fast!
>>>
>>> K.
>>>
>>
>> The lower bound for view generation is disk I/O. Temp views will never
>> be fast enough for production.
>>
>> HTH,
>> Paul Davis
>>
>>> On Fri, Apr 10, 2009 at 10:04 AM, Wout Mertens <wout.mertens@gmail.com>
wrote:
>>>>
>>>> On Apr 10, 2009, at 11:46 AM, Sho Fukamachi wrote:
>>>>
>>>>> the obvious followup question to those examples is "well, how do I find
a
>>>>> document with all of (n) tags?".
>>>>
>>>> How about this algorithm. Needed: tagcount view and document-by-tag view
>>>>
>>>> - given a list of tags that the document should have
>>>> - find the tag that has the lowest document count with the tagcount view
>>>> - request all documents with that tag through the document-by-tag view
>>>> - filter manually on documents that match
>>>>
>>>> If that would mean too many documents, make a view that emits all
>>>> combinations of 2 tags a document has, that way you filter by that much
>>>> more.
>>>>
>>>> It would be neat if one could post a temporary view that runs against a
>>>> subset of the output of a real view. That way the viewserver farm could do
>>>> the filtering...
>>>>
>>>> Wout.
>>>>
>>>
>>
>

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