You may try define a hive table with hbase storage handler n then query it ..though response time will be slow based on how much data you have On Oct 11, 2012 4:19 PM, <[email protected]> wrote:
> Hi Anoop, > Thanks a lot for your reply, > Actually our requirment is just to count the distinct deptno from emp > ( Hbase table), We are running various pentaho jobs and we need to test > the validity of the results, for that we need the below query. > > We need a query to select distinct deptno from emp Hbase table. > > Example :- > HBase Table name :- emp, column_family := cf > Let us say deptno is the field in the column family cf > > emp > ---- > deptno > 10 > 20 > 30 > 10 > 10 > 10 > > The Result should be > The count (distinct deptno) = 3 > > We need just the query to know the count of distinct deptno . > > Thanks > Regards > Raviprasad. T > Mobile :- 91- 9894769541 > > > -----Anoop Sam John <[email protected]> wrote: ----- > To: "[email protected]" <[email protected]> > From: Anoop Sam John <[email protected]> > Date: 10/11/2012 09:33AM > Cc: "[email protected]" <[email protected]> > Subject: RE: HBase table - distinct values > > Hi Ravi > If dept_no is a CF:qualifier, to know all the dept numbers > (distinct or not) you need a full table scan. As Doug said if it is a > frequent online query don't think MR is a good choice.. If the data in > your emp table is huge a full table scan also wont be that good I feel.... > Can you guys think about storing dept number in another table? If you > people need query like select <empdetails> from emp where dept_no=? (this > query also) you can think about creating secondary index implementation > and indexing dept_no... You can use index table for above query as well as > the 1st one you asked about. :) > > -Anoop- > ________________________________________ > From: [email protected] [[email protected]] > Sent: Wednesday, October 10, 2012 7:51 PM > To: [email protected] > Cc: [email protected]; [email protected] > Subject: RE: HBase table - distinct values > > Hi, > Hbase table name :- emp > Column family :- cf > Under the column family cf we will be having the field name deptno > > > Regards > Raviprasad. T > Mobile :- 91- 9894769541 > > > -----Anoop Sam John <[email protected]> wrote: ----- > To: "[email protected]" <[email protected]>, " > [email protected]" <[email protected]> > From: Anoop Sam John <[email protected]> > Date: 10/10/2012 06:18PM > Subject: RE: HBase table - distinct values > > Hi > Your schema? 'deptno' is a cf:qualifier? > > -Anoop- > ________________________________________ > From: [email protected] [[email protected]] > Sent: Wednesday, October 10, 2012 4:29 PM > To: [email protected]; [email protected] > Subject: HBase table - distinct values > > Hi all, > Is it possible to select distinct value from Hbase table. > > Example :- > what is the equivalant code for the below Oracle code in Hbase ? > > Select count (distinct deptno) from emp ; > > Regards > Raviprasad. T > > > This e-Mail may contain proprietary and confidential information and is > sent for the intended recipient(s) only. If by an addressing or > transmission error this mail has been misdirected to you, you are requested > to delete this mail immediately. You are also hereby notified that any use, > any form of reproduction, dissemination, copying, disclosure, modification, > distribution and/or publication of this e-mail message, contents or its > attachment other than by its intended recipient/s is strictly prohibited. > > Visit us at http://www.polarisFT.com > > > This e-Mail may contain proprietary and confidential information and is > sent for the intended recipient(s) only. If by an addressing or > transmission error this mail has been misdirected to you, you are requested > to delete this mail immediately. You are also hereby notified that any use, > any form of reproduction, dissemination, copying, disclosure, modification, > distribution and/or publication of this e-mail message, contents or its > attachment other than by its intended recipient/s is strictly prohibited. > > Visit us at http://www.polarisFT.com > > > This e-Mail may contain proprietary and confidential information and is > sent for the intended recipient(s) only. If by an addressing or > transmission error this mail has been misdirected to you, you are requested > to delete this mail immediately. You are also hereby notified that any use, > any form of reproduction, dissemination, copying, disclosure, modification, > distribution and/or publication of this e-mail message, contents or its > attachment other than by its intended recipient/s is strictly prohibited. > > Visit us at http://www.polarisFT.com >
