lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Raavan <valla...@gmail.com>
Subject Re: is OpenBitSet / SortedVIntList compressed bit map index?
Date Mon, 10 Jan 2011 10:00:00 GMT
Thanks Raf.

On Sun, Jan 9, 2011 at 1:20 AM, Raf <r.ventaglio@gmail.com> wrote:

> On Sat, Jan 8, 2011 at 7:24 PM, Raavan <vallalku@gmail.com> wrote:
>
> > Also, just for my understanding, is SortedVIntList able to perform some
> > operations such as AND/OR without decompression ?
> >
>
> No, not natively:
>
> http://lucene.apache.org/java/3_0_2/api/core/org/apache/lucene/util/SortedVIntList.html
>
> But the *iterator* returns the *docIds* by order and there is a
> *constructor
> *that accepts a *DocIdSetIterator*.
>
> So it's quite easy to implement the AND/OR operations by creating a *
> DocIdSetIterator *that receives the two iterators from the original *
> SortedVIntLists* and scans them in parallel, implementing *nextDoc* and *
> advance* methods accordingly to AND/OR semantic.
>
> We use something like that and, for very sparse bitsets, it is more
> efficient than to convert them in *OpenBitSets* in order to perform AND/OR
> operations.
>
> Bye
> *Raf*
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message