Re: swarm and database

[Alex Lancaster]

>>>>> "DR" == david ROBIN <address@hidden> writes:

DR> Hi,i am using swarm in java under NT and i want to know if it is
DR> possible to get initialisations parameters from a database,
DR> instead of a ".scm" file.

David,

The HDF5 serialization backend for Swarm is a "database" oriented
solution.  HDF5 saves information in a binary compressed form, which
can be accessed in a random-access fashion (i.e.  you give the
database a "key" and you have efficient hash-table look-up).

The advantages are:

1) Swarm supports HDF5 directly (i.e. you save objects with the same
API as you do for Scheme files) via the "Archiver" protocol (you set a
flag to use HDF5 when you create the "Archiver" object).

2) R (a free S-Plus like clone statistics package) has been enhanced
(by Marcus) to read HDF5 files directly.

HDF5 is particularly useful when you have large homogeneous data sets
(like big vectors) which don't need to be human-readable and/or for
objects that are relatively "flat" (i.e. don't contain
many objects-with-objects).

Links to R and HDF5 can be found at:

 http://www.santafe.edu/projects/swarm/release-apps.html#support

There are a number of bits of example code that Marcus has posted to
Swarm Support in the past.  Do a search on the archive with the
keyword "HDF5".

If you want to use an SQL database (like MySQL [free] or Oracle
[commercial]) you could go ahead and write an interface, there's
nothing in principle with Swarm that makes this impossible, and it
would be someday nice to have such a beast, but it's probably not a
high-priority right now.

Hope this helps.

 --- Alex 

-- 
Alex Lancaster * address@hidden * www.santafe.edu/~alex * 505 984-8800 x242
Santa Fe Institute (www.santafe.edu) & Swarm Development Group (www.swarm.org)

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