Re: [bailey-developers] Features and their design

[Yonik S. <yo...@ap...>]

On Thu, Mar 6, 2008 at 5:47 PM, Ning Li <nin...@gm...> wrote:
>  5 A document database?
>   - We store documents anyway.
>   - We don't support sub-document updates.

Field updates?  We could if we store all the fields.  Solr has a patch
for this, but it might be more efficient to implement in Lucene.  It
requires being able to get the *latest* stored fields for a doc, even
if they are uncommitted.

>  Here are a few comments on the features:
>  1 Consistent hashing uses hash values because hash values
>   distribute uniformly on the ring. Can we support
>   application-specified keys for the ring?

Seems like we could allow the user to specify their own hash value.
What's the usecase here?

> The difference
>  is that the distribution may not be uniform so we need
>  to rebalance sometimes (remove a virtual node and insert
>  it somewhere else).

I'll refer back again to my comments on separating replication (the
range of node X is replicated on nodes X-1 and X-2) from key
partitioning (the range of node X is 0-1000 + 5000-6000 for example).
One can change the key partitioning w/o touching the replication configuration.

>  1 On the assumption that an application specifies document
>   version number. It greatly simplifies things, but is
>   it practical?

I think so...
If the application can't provide it, the server (or client proxy)
could perhaps provide it via a timestamp.

-Yonik