[Sqlalchemy-tickets] [sqlalchemy] #2778: per-attribute callables due to options, possible reorg to remove performance overhead

[sqlalchemy <mi...@zz...>]

#2778: per-attribute callables due to options, possible reorg to remove
performance overhead
--------------------+--------------------------------------------
 Reporter:  zzzeek  |           Owner:  zzzeek
     Type:  defect  |          Status:  new
 Priority:  medium  |       Milestone:  0.9.0
Component:  orm     |        Severity:  very major - up to 2 days
 Keywords:          |  Progress State:  in queue
--------------------+--------------------------------------------
 e.g.

 {{{
  827855   15.668    0.000   27.068    0.000 …/SQLAlchemy-0.8.1-py2.6
 -linux-
 x86_64.egg/sqlalchemy/orm/strategies.py:184(set_deferred_for_local_state)
    827855   10.524    0.000   10.524    0.000 …/SQLAlchemy-0.8.1-py2.6
 -linux-x86_64.egg/sqlalchemy/orm/strategies.py:259(__init__)
 }}}

 so here we'd want to see how to have an unloaded attribute's default lazy
 callable routine access what was set up for the query that loaded this.  I
 think the mapper's loading of the state would have to assemble some aspect
 of the QueryContext into each state, which is then consulted by the
 instancestate before we do deferred_scalar_loader.  for LazyLoader the
 issue might be a little different.

 something to look into for 0.9 though not critical

--
Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2778>
sqlalchemy <http://www.sqlalchemy.org/>
The Database Toolkit for Python