On Jul 4, 2009, at 8:04 AM, Ingo Strüwing wrote:
> If the data dictionary is in the engine, how do you know, which engine
> serves a certain table?
Engines are asked in order, with the default being first, about who
has the table (assuming it is not already in the TableShare cache).
The default implementation is only called once (aka... backup DFE for
engines which lack a dictionary).
Seeing how the vast majority use just one engine the hit cost is
practically the same as having just one centralized system. Toss in
the relatively few numbers of tables compared to the size of the
TableCache and... you never see a issue.
At some point the cache itself will be pushed down for the engine to
be able to handle as well, this allows a greater degree of ability for