[Twisted-Python] Atop questions

[Guy Robinson]

I posted this to Divmod mailing list, but perhaps that's not the right place
for these sort of questions?

Hello,

I've just started to play around with Atop. I'm wanting to store data on what
could get up to 500,000 unique products. The structure of the data for each item
is the same or similar. There will be references between data in different
products. Frequent querying of products will occur from the client application.

Should I use nested Pools or, SubStores and Pools/items within each substore?

  From the documentation I can find, the advantages of Pools are easier
referencing and indexing, while substores present better security features and
scalability(less memory)? The documentation also says substores are used more
frequently in most applications. Why?

Are there other issues I should consider?

Another question :-)

A number of the atop examples define Interface classes even though they have no
methods. Is this to make upgrading of object schema easier? Why do this?

TIA,

Guy