lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Shai Erera (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (LUCENE-4609) Write a PackedIntsEncoder/Decoder for facets
Date Fri, 08 Feb 2013 13:43:13 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-4609?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13574484#comment-13574484
] 

Shai Erera commented on LUCENE-4609:
------------------------------------

Well ... this encoding may be better if really you had many more values in the range 128-256
(which w/ vint are encoded w/ 2 bytes). But that seems arbitrary .. why those values?

I am not sure if we should keep this encoder, b/c it consumes more space and even in EncodingSpeed,
which indexes categories that are very close to each other, vint achieved slightly better
compression.

I am not sure anymore that for an arbitrary set of integers, we can do better than VInt (well,
just b/c of all the attempts we've had :)).
                
> Write a PackedIntsEncoder/Decoder for facets
> --------------------------------------------
>
>                 Key: LUCENE-4609
>                 URL: https://issues.apache.org/jira/browse/LUCENE-4609
>             Project: Lucene - Core
>          Issue Type: New Feature
>          Components: modules/facet
>            Reporter: Shai Erera
>            Priority: Minor
>         Attachments: LUCENE-4609.patch, LUCENE-4609.patch, LUCENE-4609.patch, LUCENE-4609.patch,
LUCENE-4609.patch, SemiPackedEncoder.patch
>
>
> Today the facets API lets you write IntEncoder/Decoder to encode/decode the category
ordinals. We have several such encoders, including VInt (default), and block encoders.
> It would be interesting to implement and benchmark a PackedIntsEncoder/Decoder, with
potentially two variants: (1) receives bitsPerValue up front, when you e.g. know that you
have a small taxonomy and the max value you can see and (2) one that decides for each doc
on the optimal bitsPerValue, writes it as a header in the byte[] or something.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: dev-help@lucene.apache.org


Mime
View raw message