Yes, but implementing a constraint requires implementing a coprocessor, which is not something I'd recommend to users as a general practice. HBase doesn't offer referential integrity as commonly understood in the RDBMS world (foreign keys, etc.) out of the box.
On Sat, Feb 16, 2013 at 6:52 PM, Ted Yu <[email protected]> wrote: > Some addendum to Benoit's answers. > In HBase you can setup Constraint for your table. From javadoc: > > * Apply a {@link Constraint} (in traditional database terminology) to a > HTable. > > * Any number of {@link Constraint Constraints} can be added to the table, > in > > * any order. > See > hbase-server/src/main/java/org/apache/hadoop/hbase/constraint/Constraint.java > > Cheers > > On Sat, Feb 16, 2013 at 4:48 PM, tsuna <[email protected]> wrote: > > > bcc: asynchbase@ > > > > On Sat, Feb 16, 2013 at 12:28 PM, Steve Berg <[email protected]> > > wrote: > > > I have some questions for HBase DB: > > > > Hi Steve, > > I'm moving this thread to the HBase user mailing list. > > > > > How to ensure data integrity? > > > > Data stored by HBase in HDFS has 3 replicas of the data and checksums. > > > > > Are there methods ensure the integrity? > > > > It's all built-in, I'm not sure what you meant by "methods" here. > > > > > Does HBase primary key? or alternatives > > > > HBase has only one primary key per table. > > You may wanna look at the HBase Book, Chapter 5. "Data Model": > > http://hbase.apache.org/book.html#datamodel > > > > > Foreign key? > > > > No. > > > > > Referential Integrity? > > > > No. > > > > > How are the ACID properties to be implemented? > > > > http://hbase.apache.org/acid-semantics.html > > > > -- > > Benoit "tsuna" Sigoure > > > -- Best regards, - Andy Problems worthy of attack prove their worth by hitting back. - Piet Hein (via Tom White)
