Re: [Pytables-users] Query speed: Table (very fast) vs' Array (slow)

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

A Saturday 29 January 2011 20:20:15 Raphael Weingartner escrigué:
[clip]
> Question:
> Why is openFile reading the original data file as an array.Array
> object if querying tables is so much faster?

The quick answer is that PyTables is specially tuned for, well, tables.  
And these entities wear special I/O buffers and query engines that are 
fined tuned for maximum speed.  *Array objects do not wear the same 
machinery.

By the way, you can get still faster queries by using the `where()` 
method:

result = [x for x in h5fast.root.detector.where('pnum==7848107')]

For faster access, you can also use the indexation feature in PyTables 
Pro.  See:

http://www.pytables.org/docs/manual/ch05.html#searchOptim

for some benchmarks and advices on getting maximum query speed.

Hope this helps,

-- 
Francesc Alted