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From Rohit Kelkar <rohitkel...@gmail.com>
Subject Re: Migrating Tables with primary key and foreign key from mysql to Hbae
Date Wed, 28 Mar 2012 05:30:42 GMT
In my opinion it is a bad idea to "copy paste" a normalized schema
from an RDBMS to a nosql database like hbase. Hbase encourages
denormalization. Hbase does not support indexing out of the box like
mysql/postgres/etc. So your retrieval time would be affected as the
data size grows. For indexing in hbase you have to separately create
indexes either as a hbase table or use solr, etc.
For purposes of understanding hbase you can treat the primary key to
be equivalent to the row key in hbase. I don't think there is any
concept of foreign keys in hbase but you could explore coprocessors in
hbase to implement something that is equivalent to foreign keys.

- Rohit Kelkar

On Wed, Mar 28, 2012 at 10:05 AM, Neetu Ojha <neetuojha.cdac@gmail.com> wrote:
> Hi Jean,
>  Thanks A lot for reply, I got your point about HBASE , let me give a
> little clear picture of what I am desiring from HBase , If any body is
> willing to migrate ones application on Hadoop and at teh same time migrate
> Mysql database to Hbase to get the advantage of the Hbase in that case if
> migrate Mysql databae or any relational database to Hbase using tools like
> sqoop , but as the database in mysql has tables relation's maintained with
> foreign key , primary key so what need to be done Hbase side to maintain
> the integrity and dependency of one data on the other or its totally a bad
> idea to migrate from Relational database to Hbase.
> PLease through some light on that if possible.
> And I am sure many people must have faced this situation while working
> wkith Hadoop, Hbase for first time.
> REgards
> Neetu
> On Wed, Mar 28, 2012 at 12:43 AM, Jean-Daniel Cryans <jdcryans@apache.org>wrote:
>> Hi,
>> HBase is not a relational database, it doesn't have foreign keys or
>> constraints. I'd suggest you familiarize yourself with HBase by
>> reading the refence manual[1] or buying the book[2].
>> Regards,
>> J-D
>> 1. http://hbase.apache.org/book/book.html
>> 2. http://www.amazon.com/dp/1449396100
>> On Tue, Mar 27, 2012 at 5:25 AM, Neetu Ojha <neetuojha.cdac@gmail.com>
>> wrote:
>> > Dear all,
>> >
>> > I used sqoop tool to migrate the mysql table to hbase but I have not got
>> > any clearity yet that how the primary keys and foreign keys are preserved
>> > in Hbase for the tables migrated from mysql database to hbase so that
>> user
>> > can access the tables from hbase with having the assurance of the data
>> > integrity and behaviour as it was on Mysql database.
>> >
>> > My idea is ti present Hbase as Cloud storage solution and where users can
>> > migrate there mysql database to Hbase and the behaviour and data
>> integrity
>> > is entact too.
>> >
>> > If any one has experience of the same or idea please share with me.
>> >
>> >
>> > Thanks & Regards
>> > Neetu

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