Michael, I don’t understand the invective. I’m sure you have something to contribute but when bring on this tone the only thing I hear are the snide comments.
-j P.s., I’ll refer you to this: https://hbase.apache.org/book.html#_joins On 3/16/15, 11:15 AM, "Michael Segel" <michael_se...@hotmail.com> wrote: >You’ll have to excuse Andy. > >He’s a bit slow. HBASE-13044 should have been done 2 years ago. And it >was trivial. Just got done last month…. > >But I digress… The long story short… > >HBASE-9203 was brain dead from inception. Huawei’s idea was to index on >the region which had two problems. >1) Complexity in that they wanted to keep the index on the same region >server >2) Joins become impossible. Well, actually not impossible, but >incredibly slow when compared to the alternative. > >You really should go back to the email chain. >Their defense (including Salesforce who was going to push this approach) >fell apart when you asked the simple question on how do you handle joins? > >That’s their OOPS moment. Once you start to understand that, then >allowing the index to be orthogonal to the base table, things started to >come together. > >In short, you have a query either against a single table, or if you’re >doing a join. You then get the indexes and assuming that you’re only >using the AND predicate, its a simple intersection of the index result >sets. (Since the result sets are ordered, its relatively trivial to walk >through and find the intersections of N Lists in a single pass.) > > >Now you have your result set of base table row keys and you can work with >that data. (Either returning the records to the client, or as input to a >map/reduce job. > >That’s the 30K view. There’s more to it, but once Salesforce got the >basic idea, they ran with it. It was really that simple concept that the >index would be orthogonal to the base table that got them moving in the >right direction. > > >To Joseph’s point, indexing isn’t necessarily an RDBMS feature. However, >it seems that some of the Committers are suffering from rectal induced >hypoxia. HBASE-12853 was created not just to help solve the issue of ‘hot >spotting’ but also to get the Committers to focus on bringing the >solutions that they glum on in the client, back to the server side of >things. > >Unfortunately the last great attempt at fixing things on the server side >was the bastardization of coprocessors which again, suffers from the lack >of thought. This isn’t to say that allowing users to extend the server >side functionality is wrong. (Because it isn’t.) But that the >implementation done in HBase is a tad lacking in thought. > >So in terms of indexing… >Longer term picture, there has to be some fixes on the server side of >things to allow one to associate an index (allowing for different types) >to a base table, yet the implementation of using the index would end up >becoming a client. And by client, it would be an external query engine >processor that could/should sit on the cluster. > >But hey! What do I know? >I gave up trying to have an intelligent/civilized conversation with >Andrew because he just couldn’t grasp the basics. ;-) > > > > > >> On Mar 13, 2015, at 4:14 PM, Andrew Purtell <apurt...@apache.org> wrote: >> >> When I made that remark I was thinking of a recent discussion we had at >>a >> joint Phoenix and HBase developer meetup. The difference of opinion was >> certainly civilized. (smile) I'm not aware of any specific written >> discussion, it may or may not exist. I'm pretty sure a revival of >>HBASE-9203 >> would attract some controversy, but let me be clearer this time than I >>was >> before that this is just my opinion, FWIW. >> >> >> On Thu, Mar 12, 2015 at 3:58 PM, Rose, Joseph < >> joseph.r...@childrens.harvard.edu> wrote: >> >>> I saw that it was added to their project. I’m really not keen on >>>bringing >>> in all the RDBMS apparatus on top of hbase, so I decided to follow >>>other >>> avenues first (like trying to patch 0.98, for better or worse.) >>> >>> That Phoenix article seems like a good breakdown of the various >>>indexing >>> architectures. >>> >>> HBASE-9203 (the ticket that deals with 2’ indexes) is pretty civilized >>>(as >>> are most of them, it seems) so I didn’t know there were these >>>differences >>> of opinion. Did I miss the mailing list thread where the architectural >>> differences were discussed? >>> >>> >>> -j > >The opinions expressed here are mine, while they may reflect a cognitive >thought, that is purely accidental. >Use at your own risk. >Michael Segel >michael_segel (AT) hotmail.com > > > > >
