Re: [Pytables-users] performance question ( with source )

[Francesc A. <fa...@ca...>]

A Dimarts 27 Setembre 2005 20:21, Stefan Kuzminski va escriure:
> Ahh, that's the ticket.  I can get the throughput I need now ( >4000tps
> )!!  Another quick questions or so..

Excellent!

> 1.  If I use a dictionary as a table description ( rather than a
> IsDescrition subclass ), how do I tell it what order the columns are?
> Dictionaries are non-ordered?

You can use the ._v_names attribute of table description. For example:

In [8]:f.root.newgroup.table.description._v_names
Out[8]:['name', 'lati', 'longi', 'pressure', 'temperature']


> 2.  Is there some type of SQL interface built on top of pyttables?

Not as such, but there are several ways to do data selections in
tables, namely, general selections, in-kernel selections and indexed
selections. Look at:

http://pytables.sourceforge.net/doc/SciPy04.pdf

for some directions, experiments, recomendations and limitations about
data selections.

Or do you need something different from selections?

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