Re: [Sqlalchemy-tickets] [sqlalchemy] #2779: Join order determinism in polymorphic loads

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

#2779: Join order determinism in polymorphic loads
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      Reporter:  aelaguiz         |      Owner:  zzzeek
          Type:  defect           |     Status:  new
      Priority:  medium           |  Milestone:
     Component:  cextensions      |   Severity:  no triage selected yet
    Resolution:                   |   Keywords:
Progress State:  awaiting triage  |
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Comment (by zzzeek):

 the current spot where ordering isn't deterministic on this one appears to
 be:

 {{{
 #!diff
 --- a/lib/sqlalchemy/orm/mapper.py
 +++ b/lib/sqlalchemy/orm/mapper.py
 @@ -1798,7 +1798,7 @@ class Mapper(_InspectionAttr):
          while stack:
              item = stack.popleft()
              descendants.append(item)
 -            stack.extend(item._inheriting_mappers)
 +            stack.extend(sorted(item._inheriting_mappers, key=lambda m:
 m.class_.__name__))
          return util.WeakSequence(descendants)

      def polymorphic_iterator(self):
 }}}

 but I'd want to look into the best way for this list to be sorted, perhaps
 even using WeakSequence for item._inheriting_mappers in the first place.

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2779#comment:2>
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