On Sep 27, 2007, at 3:53 PM, [EMAIL PROTECTED] wrote:
> > i know in 0.4 one can request a polymorphic request to be automaticaly > split into multiple per-subtype requests. i've no idea how this > compares +/- to the huge union/outerjoin that gives all in one long > shot. > > my question is.. can this mechanism/approach be used somehow for > (semi) automatic "vertical" loading, i.e. instead of loading all > items in all rows, load only some items normaly while (pre)loading > some specific columns in whole in one separate shot? > say there is a table X having a,b,c..p,q. So i do a plain row query > over X, getting a,b,c,d per row, and request the p and q columns > (pre)loaded whole (or partial as per some limit). > i imagine this to be useful to avoid zillions of eagerloads/joins etc > (when the columns in question are links to somewhere). > but i might be wrong... - i've no idea how the eagerloading scales. > Any arguments pro/con? if youre talking about just one table X, "deferred" columns will hold off the loading of those columns until they are accessed. as far as the joined tables, polymorphic_fetch="deferred" will leave those to be loaded when those attributes are first accessed. that's as well as I understand your question so far.... --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
