[p2p-hackers] DHT and complex queries

[Michael Rogers]

Hi Davide,

In theory it should be possible to build any pointer-based data 
structure using DHT IDs instead of pointers. For example you could use a 
sorted linked list to support range queries - each record would contain 
the IDs of the previous and next records. (The IDs would be distributed 
uniformly, as usual.) However, in practice I'm not sure if a DHT would 
provide strong enough consistency guarantees. In the case of a linked 
list I guess you could store "backup" pointers to the second-next 
record, third-next etc, rather like Chord's successor list. (Anyone know 
of any work on fault-tolerant data structures?)

Just a thought,
Michael

Davide Carboni wrote:

>Hi, I'm developing a P2P system where clients must be able to send
>complex queries such as:
>
>author equal "foo"
>and
>publicationDate is between "12 12 1999" and "12 12 2000"
>andnot
>distributor startswith "galax"
>
>etc. etc.
>
>I'm reading some papers about DHT and I wonder whether or not DHT is a
>viable solution for these requirements. I know that with DHT you can
>map a key onto a piece of data, but I cannot see how to manage complex
>query like the one in the example. Probably DHT is not the "good"
>solution for this...but never know,
>
>Any hints?
>Bye.
>Davide
>
>
>  
>