When you start looking at secondary indexing, they really become powerful when you want to join two tables.
(Something I thought was already being discussed....)
So you can use the inverted table as a secondary index with one small glitch...
And then create a table of indexes. Where each row represents an index and the columns are the rowkeys in that index.
(Call it a foreign key table.)
Now for the glitch... what happens when your row exceeds the width of your region. ;-)
There's a solution for that. ;-)
The other issue would be asynchronous writes.
I figured that one should get the talk started now, rather than wait until later.
This is why you want secondary indexes., the other issue... theta joins but lets save that for later.
The opinions expressed here are mine, while they may reflect a cognitive thought, that is purely accidental.
Use at your own risk.
michael_segel (AT) hotmail.com