Hi,
I'm looking for an example of the constraints in HBase with |void check
(put p)|, this is indeed possible, but how? Does anyone possible
examples (code) to?
Ever advance thank you!
best regards!
Am 18.02.2013 01:15, schrieb Andrew Purtell:
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]
<mailto:[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]
<mailto:[email protected]>> wrote:
> bcc: asynchbase@
>
> On Sat, Feb 16, 2013 at 12:28 PM, Steve Berg
<[email protected] <mailto:[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)
