You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@mahout.apache.org by "Sean Owen (JIRA)" <ji...@apache.org> on 2010/05/11 21:23:44 UTC
[jira] Resolved: (MAHOUT-391) Make vector more space efficient with
variable-length encoding, et al
[ https://issues.apache.org/jira/browse/MAHOUT-391?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sean Owen resolved MAHOUT-391.
------------------------------
Resolution: Fixed
Yeah I think that's a solid win, and about what I'd expect on average in real life. 11% less storage and network traffic at this scale is significant. Committed.
> Make vector more space efficient with variable-length encoding, et al
> ---------------------------------------------------------------------
>
> Key: MAHOUT-391
> URL: https://issues.apache.org/jira/browse/MAHOUT-391
> Project: Mahout
> Issue Type: Improvement
> Affects Versions: 0.3
> Reporter: Sean Owen
> Assignee: Sean Owen
> Priority: Minor
> Fix For: 0.4
>
> Attachments: MAHOUT-391.patch, MAHOUT-391.patch
>
>
> There are a few things we can do to make Vector representations smaller on disk:
> - Use variable-length encoding for integer values like size and element indices in sparse representations
> - Further, delta-encode indices in sequential representations
> - Let caller specify that precision isn't crucial in values, allowing it to store values as floats
> Since indices are usually small-ish, I'd guess this saves 2 bytes or so on average, out of 12 bytes per element now.
> Using floats where applicable saves another 4. Not bad.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.