I have taken a quick look at phoenix. It's baked into HBase-specific features pretty hard.
It uses coprocessors to do things like create index entries. This is a common enough idiom in the HBase community, but not something we've supported in Accumulo. In general, you do not want an accumulo Iterator or Constraint generating data for other tables. However, a more sophisticated Percolator type implementation ( https://github.com/keith-turner/Accismus) could support index generation and query transactions. We could probably re-use a lot of it, but it's not going to be as simple as changing the classes that talk to the database back-end. -Eric On Tue, Apr 29, 2014 at 9:21 AM, Kepner, Jeremy - 0553 - MITLL < kep...@ll.mit.edu> wrote: > Hi James, > Can you explain how the SQL layer to HBase works? > Regards. -Jeremy > > On Apr 29, 2014, at 1:32 AM, James Taylor <jamestay...@apache.org> > wrote: > > > Hello, > > Would there be any interest in developing a SQL-layer on top of Accumulo? > > I'm part of the Apache Phoenix project and we've built a similar system > on > > top of HBase. I wanted to see if there'd be interest on your end at > working > > with us to generalizing our client and provide in a server that would do > > Accumulo-specific push down in support of a SQL layer. I suspect there's > > enough similarity between HBase and Accumulo that this would be feasible. > > Thanks, > > James > >
