It sounds, of course, a lot like transaction isolation using MVCC. It's the obvious solution, and has been for since the late 1970's.
I hope it won't be too hard to convince people to use it :-) It's been the reason for the early success of Oracle. Dennis Gearon Signature Warning ---------------- It is always a good idea to learn from your own mistakes. It is usually a better idea to learn from others’ mistakes, so you do not have to make them yourself. from 'http://blogs.techrepublic.com.com/security/?p=4501&tag=nl.e036' EARTH has a Right To Life, otherwise we all die. --- On Mon, 10/11/10, Yonik Seeley <yo...@lucidimagination.com> wrote: > From: Yonik Seeley <yo...@lucidimagination.com> > Subject: Re: LuceneRevolution - NoSQL: A comparison > To: solr-user@lucene.apache.org > Date: Monday, October 11, 2010, 7:20 PM > On Mon, Oct 11, 2010 at 8:32 PM, > Peter Keegan <peterlkee...@gmail.com> > wrote: > > I listened with great interest to Grant's presentation > of the NoSQL > > comparisons/alternatives to Solr/Lucene. It sounds > like the jury is still > > out on much of this. Here's a use case that might > favor using a NoSQL > > alternative for storing 'stored fields' outside of > Lucene. > > > > When Solr does a distributed search across shards, it > does this in 2 phases > > (correct me if I'm wrong): > > > > 1. 1st query to get the docIds and facet counts > > 2. 2nd query to retrieve the stored fields of the top > hits > > > > The problem here is that the index could change > between (1) and (2), so it's > > not an atomic transaction. > > Yep. > > As I discussed with Peter at Lucene Revolution, if this > feature is > important to people, I think the easiest way to solve it > would be via > leases. > > During a query, a client could request a lease for a > certain amount of > time on whatever index version is used to generate the > response. Solr > would then return the index version to the client along > with the > response, and keep the index open for that amount of > time. The client > could make consistent additional requests (such as the 2nd > phase of a > distributed request) by requesting the same version > of the index. > > -Yonik >
