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HBase >> mail # user >> Pagination with HBase - getting previous page of data


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Re: Pagination with HBase - getting previous page of data
Yes, your suggested solution only works on RowKey based pagination. It will
fail when you start filtering on the basis of columns.

Still, i would say it's comparatively easier to maintain this at
Application level rather than creating tables for pagination.

What if you have 300 columns in your schema. Will you create 300 tables?
What about handling of pagination when filtering is done based on multiple
columns ("and" and "or" conditions)?

On Tue, Jan 29, 2013 at 1:08 PM, Jean-Marc Spaggiari <
[EMAIL PROTECTED]> wrote:

> No, no killer solution here ;)
>
> But I'm still thinking about that because I might have to implement
> some pagination options soon...
>
> As you are saying, it's only working on the row-key, but if you want
> to do the same-thing on non-rowkey, you might have to create a
> secondary index table...
>
> JM
>
> 2013/1/27, anil gupta <[EMAIL PROTECTED]>:
> > That's alright..I thought that you have come-up with a killer solution.
> So,
> > got curious to hear your ideas. ;)
> > It seems like your below mentioned solution will not work on filtering on
> > non row-key columns since when you are deciding the page numbers you are
> > only considering rowkey.
> >
> > Thanks,
> > Anil
> >
> > On Fri, Jan 25, 2013 at 6:58 PM, Jean-Marc Spaggiari <
> > [EMAIL PROTECTED]> wrote:
> >
> >> Hi Anil,
> >>
> >> I don't have a solution. I never tought about that ;) But I was
> >> thinking about something like you create a 2nd table where you place
> >> the raw number (4 bytes) then the raw key. You go directly to a
> >> specific page, you query by the number, found the key, and you know
> >> where to start you scan in the main table.
> >>
> >> The issue is properly the number for each lines since with a MR you
> >> don't know where you are from the beginning. But you can built
> >> something where you store the line number from the beginning of the
> >> region, then when all regions are parsed you can reconstruct the total
> >> numbering... That should work...
> >>
> >> JM
> >>
> >> 2013/1/25, anil gupta <[EMAIL PROTECTED]>:
> >> > Inline...
> >> >
> >> > On Fri, Jan 25, 2013 at 9:17 AM, Jean-Marc Spaggiari <
> >> > [EMAIL PROTECTED]> wrote:
> >> >
> >> >> Hi Anil,
> >> >>
> >> >> The issue is that all the other sub-sequent page start should be
> moved
> >> >> too...
> >> >>
> >> > Yes, this is a possibility. Hence the Developer has to take care of
> >> > this
> >> > case. It might also be possible that the pageSize is not a hard limit
> >> > on
> >> > number of results(more like a hint or suggestion on size). I would say
> >> > it
> >> > varies by use case.
> >> >
> >> >>
> >> >> so if you want to jump directly to page n, you might be totally
> >> >> shifted because of all the data inserted in the meantime...
> >> >>
> >> >> If you want a real complete pagination feature, you might want to
> have
> >> >> a coproccessor or a MR updating another table refering to the
> >> >> pages....
> >> >>
> >> > Well, the solution depends on the use case. I will be doing pagination
> >> > in
> >> > HBase for a restful service but till now i am unable to find any
> reason
> >> why
> >> > this cant be done at application level.
> >> > Are you suggesting to use MR for paging in HBase? If yes, how?
> >> > How would you use another table for pagination?what would you store in
> >> the
> >> > extra table?
> >> >
> >> >>
> >> >> JM
> >> >>
> >> >> 2013/1/25, anil gupta <[EMAIL PROTECTED]>:
> >> >> > Hi Vijay,
> >> >> >
> >> >> > I've done paging in HBase by using Scan only(no pagination filter)
> >> >> > as
> >> >> > Mohammed has explained. However it was just an experimental stuff.
> >> >> > It
> >> >> works
> >> >> > but Jean raised a very good point.
> >> >> > Find my answer inline to fix the problem that Jean reported.
> >> >> >
> >> >> >
> >> >> > On Fri, Jan 25, 2013 at 4:38 AM, Jean-Marc Spaggiari <
> >> >> > [EMAIL PROTECTED]> wrote:
> >> >> >
> >> >> >> Hi Vijay,
> >> >> >>
> >> >> >> If, while the user os scrolling forward, you store the key of each

Thanks & Regards,
Anil Gupta
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB