I use SA on a daily basis and its feature set is awesome. I recommend to you using the declarative layer http://www.sqlalchemy.org/docs/05/ormtutorial.html#creating-table-class-and-mapper-all-at-once-declaratively This makes it easier to you, to jump into SA. Moreover, the declarative extension is officially supported on the SA mailing list. There exists also an o'Reilly book on SA.
Michael On 27 Mai, 18:17, William Stein <wst...@gmail.com> wrote: > On Wed, May 27, 2009 at 1:49 AM, Simon King <simon.k...@uni-jena.de> wrote: > > > Hi! > > > The mission statement or our project on cohomology rings says that we > > should make a data base publically available. It should in some way be > > available for Sage (say, as an optional/experimental package), but I > > wonder if it is possible. > > > 1) An spkg just with our programs would be about 460 MB. I think this > > is ok. But a gzipped tar ball of our results (forming the data of a > > data base) would be 20 GB for about 2500 cohomology rings. Is this too > > much for inclusion into the spkg? I guess it is. > > One of the first Sage optional spkg's I ever made is 2 TB (terabytes!). > You could have your 20GB spkg listed here: > > http://sagemath.org/sagedb/ > > > > > But how else could I provide the data? Perhaps I can keep it on some > > web site (on sage.math?), for downloading the data of single > > cohomology rings on demand? > > You could certainly also do that. Just put it in a directory in your > home directory. I have directories like that: > > http://sage.math.washington.edu/home/wstein/db/modsym/data/ > > > > > 2) Having the data is one thing. Having a relational data base is a > > different thing. > > What I can do: > > Given the address (q,n) of a finite p-group in the Small Groups > > Library, my cohomology constructor first tries to find the cohomology > > data stored on disk, and if it fails then it creates the ring from > > scratch. > > What I want to be able to do: > > The data base should be able to return, say, a list of all known > > cohomology rings of depth 2, or a list of all cohomology rings with a > > given Poincare series. > > > I guess that those things are doable with sqlalchemy, but perhaps you > > have a different/better suggestion. > > Such a database would be tiny. Just store the depth and poincare > series and some pointer to each cohomology ring, which you could store > on sage.math. > > > And I would appreciate a direct pointer to manual pages that explain > > how to create a data base, given a function that returns some object > > to a given key, so that the data base relates the key with certain > > special properties (depth, Poincare series,...) of the returned > > objects. > > I would just copy an existing an example. You might also look at the > sqlalchemy web page if you want to make a relational database. > > William > > > > > Best regards, > > Simon > > -- > William Stein > Associate Professor of Mathematics > University of Washingtonhttp://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
