Yeah. Jean-Marc is right. You have to think more in terms of a hierarchical model where you’re modeling records not relationships.
Your model would look like a single ER box per record type. The HBase schema is very simple. Tables, column families and that’s it for static structures. Even then, column families tend to get misused. If you’re looking at a relational model… Phoenix or Splice Machines would allow you to do something… although Phoenix is still VERY primitive. (Do they take advantage of cell versioning like spice machines yet? ) There are a couple of interesting things where you could create your own modeling tool / syntax (relationships)… 1) HBase is more 3D than RDBMS 2D and similar to ORDBMSs. 2) You can join entities on either a FK principle or on a weaker relationship type. HBase stores CLOBS/BLOBs in each cell. Its all just byte arrays with a finite bounded length not to exceed the size of a region. So you could store an entire record as a CLOB within a cell. Its in this sense that a cell can represent multiple attributes of your object/record that you gain an additional dimension and why you only need to use a single data type. HBase and Hadoop in general allow one to join orthogonal data sets that have a weak relationship. So while you can still join sets against a FK which implies a relationship, you don’t have to do it. Imagine if you wanted to find out the average cost of a front end collision by car of college aged drivers by major. You would be joining insurance records against registrations for all of the universities in the US for those students between the ages of 17 and 25. How would you model this when in fact neither defining attribute is a FK? (This is why you need a good Secondary Indexing implementation and not something brain dead that wasn’t alcohol induced. ;-) Does that make sense? Note: I don’t know if anyone like CCCis, Allstate, State Farm, or Progressive Insurance are doing anything like this. But they could. > On Apr 5, 2015, at 7:54 PM, Jean-Marc Spaggiari <[email protected]> > wrote: > > Not sure you want to ever do that... Designing an HBase application is far > different from designing an RDBMS one. Not sure those tools fit well here. > > What's you're goal? Designing your HBase schema somewhere and then let the > tool generate your HBase tables? > > 2015-04-05 18:26 GMT-04:00 Ben Liang <[email protected]>: > >> Hi all, >> Do you have any tools to manage Data Architecture & Modeling for >> HBase( or Phoenix) ? Can we use Powerdesinger or ERWin to do it? >> >> Please give me some advice. >> >> Regards, >> Ben Liang >> >> 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
