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From Vladimir Rodionov <vrodio...@carrieriq.com>
Subject RE: How to get Last access time of a record
Date Mon, 24 Feb 2014 20:12:40 GMT
I recommend you work a little bit more on design.
NoSQL in general and HBase in particular are not very good at joining tables, but very good
at point and range queries.

Sure, you can do some optimizations in your current approach: create CACHE table as IN_MEMORY,
set TTL for say 1day (or less, depends
on the data volume your are able to store ) and utilize HBase internal block cache (which
is LRU) for that table.

Best regards,
Vladimir Rodionov
Principal Platform Engineer
Carrier IQ, www.carrieriq.com
e-mail: vrodionov@carrieriq.com

________________________________________
From: Vikram Singh Chandel [vikramsinghchandel@gmail.com]
Sent: Monday, February 24, 2014 11:38 AM
To: user@hbase.apache.org
Subject: Re: How to get Last access time of a record

Hi Vladimir,

We are going to implement cache in HBase, let me give you a example

We have two tables
Table1: 80 m records say Author
Table2 : 5k records say Category
query : Get details of all publications by Author XYZ broken down by
Category

We fire a get on Table 1 to get a list of publications ids(hashed)
Then we do a scan on  Table 2 to get list of publications for each category
and then we do Intersection
of both list and in the end get the details from publication table.

Now suppose same query comes again instead of doing all this computation
again we are going to save the intersected results
in a table we are calling L2 Cache (there's a L1 also)

Hope you would have got idea of what we are trying to achieve.
Now if you can help please





On Tue, Feb 25, 2014 at 12:20 AM, Vladimir Rodionov <vrodionov@carrieriq.com
> wrote:

> Interesting. You want to use HBase as a cache. What data are going to
> cache? Is it some kind of a cold storage
> on tapes or Blu-Ray disks? Just curious.
>
> Best regards,
> Vladimir Rodionov
> Principal Platform Engineer
> Carrier IQ, www.carrieriq.com
> e-mail: vrodionov@carrieriq.com
>
> ________________________________________
> From: Vikram Singh Chandel [vikramsinghchandel@gmail.com]
> Sent: Monday, February 24, 2014 4:25 AM
> To: user@hbase.apache.org
> Subject: Re: How to get Last access time of a record
>
> Hi
> Hbase provides cache on non processed data, we are implementing a second
> level of caching on processed data,
> for eg on intersected data between two tables, or on post processed data.
>
>
> On Mon, Feb 24, 2014 at 5:02 PM, haosdent <haosdent@gmail.com> wrote:
>
> > HBase have already maintained a cache.
> >
> > >we can get last accessed time for a record
> >
> > I think you could get this from your application level.
> >
> >
> > On Mon, Feb 24, 2014 at 7:21 PM, Vikram Singh Chandel <
> > vikramsinghchandel@gmail.com> wrote:
> >
> > > Hi
> > >
> > > We are planning to implement caching mechanism for our Hbase data model
> > for
> > > that we have to remove the *LRU (least recently used)  records* from
> the
> > > cached table.
> > >
> > > Is there any way by which we can get last accessed time for a record,
> > > primarily the access will be
> > > using *Range Scan and Get *
> > >
> > > --
> > > *Regards*
> > >
> > > *VIKRAM SINGH CHANDEL*
> > >
> > > Please do not print this email unless it is absolutely
> necessary,Reduce.
> > > Reuse. Recycle. Save our planet.
> > >
> >
> >
> >
> > --
> > Best Regards,
> > Haosdent Huang
> >
>
>
>
> --
> *Regards*
>
> *VIKRAM SINGH CHANDEL*
>
> Please do not print this email unless it is absolutely necessary,Reduce.
> Reuse. Recycle. Save our planet.
>
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> immediately notify the sender and/or Notifications@carrieriq.com and
> delete or destroy any copy of this message and its attachments.
>



--
*Regards*

*VIKRAM SINGH CHANDEL*

Please do not print this email unless it is absolutely necessary,Reduce.
Reuse. Recycle. Save our planet.

Confidentiality Notice:  The information contained in this message, including any attachments
hereto, may be confidential and is intended to be read only by the individual or entity to
whom this message is addressed. If the reader of this message is not the intended recipient
or an agent or designee of the intended recipient, please note that any review, use, disclosure
or distribution of this message or its attachments, in any form, is strictly prohibited. 
If you have received this message in error, please immediately notify the sender and/or Notifications@carrieriq.com
and delete or destroy any copy of this message and its attachments.

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