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From Ravikumar Govindarajan <ravikumar.govindara...@gmail.com>
Subject Re: Grouping on multiple shards possible in lucene?
Date Tue, 20 Nov 2012 15:37:19 GMT
But, I think it should be possible with some fun codec & merge policy
& MultiReader magic, to have docIDs assigned in "reverse chronological
order"

Can you explain it a bit more? I was thinking perhaps we store absolute
doc-ids instead of delta to do reverse traversal. But this could waste a
lot of storage

The default merge policy will merge adjacent segments no? Is it going to
disturb the ordering?

--
Ravi

On Tue, Nov 20, 2012 at 5:19 PM, Michael McCandless <
lucene@mikemccandless.com> wrote:

> On Tue, Nov 20, 2012 at 1:49 AM, Ravikumar Govindarajan
> <ravikumar.govindarajan@gmail.com> wrote:
> > Thanks Mike. Actually, I think I can eliminate sort-by-time, if I am able
> > to iterate postings in reverse doc-id order. Is this possible in lucene?
>
> Alas that is not easy to do in Lucene: the posting lists are encoded
> in forward docID order.
>
> But, I think it should be possible with some fun codec & merge policy
> & MultiReader magic, to have docIDs assigned in "reverse chronological
> order" ...
>
> > Also, for a TopN query sorted by doc-id will the query terminate early?
>
> Actually, it won't!  But it really should ... you could make a
> Collector that throws an exception once the N docs have been
> collected?
>
> Mike McCandless
>
> http://blog.mikemccandless.com
>
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