Datastore Key IDs

[ae]

Hi,

just wondering, do the datastore key ids get recycled for an entity?
or are they guaranteed to by unique for an entity? e.g. if key id 7
to 10 gets deleted, do those key id ever get used again?

Thanks

[theo]

They are supposed to be unique. I have managed to make duplicate id's
though. Keys are always unique, as far as I can tell.

[ryan]

theo is right: only entire keys (ie paths) are guaranteed to be
unique. more:

http://code.google.com/appengine/docs/datastore/keysandentitygroups.html#Entity_Groups_Ancestors_and_Paths

one corollary to this is that ids (and key names) are guaranteed to be
unique within all entities of a given kind with the same parent.
similarly, ids and key names will be unique within all root entities
of a given kind.