Re: [Pytables-users] Speed of in-kernel Full-Table Search

[Antonio V. <ant...@ti...>]

Hi Sebastian,

Il 24/06/2013 11:25, Wagner Sebastian ha scritto:
> Dear PyTables-Users,
> 
> For testing purposes I use a PyTables DB with 4 columns (1x Uint8 and 3xFloat) with 750k rows, the total file size about 90MB. As the free version does no support indexing I thought that a search (full-table) on this database would last a least one or two seconds, because the file has to be loaded first (throttleneck I/O), and then the search over ~20k rows can begin. But PyTables took only 0.05 seconds for a full table search (in-kernel, so near C-speed, but nevertheless full table), while my bisecting algorithm with a precomputed sorted list wrapped around PyTables (but saved in there), took about 0.5 seconds.
> 
> So the thing I don't understand: How can PyTables be so fast without any Indexing?
> 
> I'm using 3.0.0rc2 coming with WinPython
> 
> Regards,
> Sebastian

The indexing features of PyTables Pro are now available in the open
source version of PyTables since version 2.3 (please see [1]).



[1]
http://pytables.github.io/release-notes/RELEASE_NOTES_v2.3.x.html#changes-from-2-2-1-to-2-3

ciao

-- 
Antonio Valentino