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From Tim Robertson <timrobertson...@gmail.com>
Subject Re: Newbie question
Date Mon, 15 Nov 2010 06:47:47 GMT
>So updating is okay but Handling deletes is not possible in the current version
> of the data unless a new version of the data is written down.

Not quite.  You can delete a record and it will not show up in scans
and gets etc, but physically it will still take up space on the disk
until HBase cleans up the files - HBase effectively marks it as
deleted, but the application sitting above HBase will not see it.



> Hi All,
>
> Thank you for the feedback. So to summarize, HBase is doing good for high
> reads, writes. Update is really writing a new version of the data. So
> updating is okay but Handling deletes is not possible in the current version
> of the data unless a new version of the data is written down.
>
> Also, I was reading some documentation to figure out if there is a way to
> store and get column values in a sorted manner.
> I understand It is possible to do range queries on key (as the key is sorted
> and stored) but it looks like its not straight forward to do the same on the
> columns values. For example I have a set of column values with a name and a
> score and for a given key and i want to retrieve the column names for a
> given key sorted by the score. From my understanding so far, this has to be
> handled at the application end. Please let me know if I am missing something
> here.
>
> Thanks,
> Gayatri
>
> On Mon, Nov 15, 2010 at 10:29 AM, Ryan Rawson <ryanobjc@gmail.com> wrote:
>
>> That is a static snapshot of a particular version of HBase with a
>> particular version of their code (each with various flaws, mistakes,
>> etc, etc).
>>
>> At this moment, Stumbleupon uses HBase behind parts of it's website,
>> doing reads, writes, updates, and so on.  Performance is quite good,
>> and we are very happy with HBase.
>>
>> -ryan
>>
>> On Sun, Nov 14, 2010 at 8:54 PM, Hari Sreekumar
>> <hsreekumar@clickable.com> wrote:
>> > Hi,
>> >   I read the comparison from this pdf:
>> >   http://www.brianfrankcooper.net/pubs/ycsb-v4.pdf
>> >
>> > hari
>> >
>> >
>> > On Mon, Nov 15, 2010 at 4:20 AM, Jonathan Gray <jgray@facebook.com>
>> wrote:
>> >
>> >> HBase is well-suited for a high-write workload.
>> >>
>> >> Hari, I'm not sure what would be different in a database like Cassandra
>> >> with respect to updates and deletes?  In this regard HBase and Cassandra
>> are
>> >> nearly identical (updates are really just insertions of new versions,
>> >> deletions are actually tombstone markers... ie data is immutable once
>> >> written).
>> >>
>> >> JG
>> >>
>> >> > -----Original Message-----
>> >> > From: Hari Sreekumar [mailto:hsreekumar@clickable.com]
>> >> > Sent: Friday, November 12, 2010 6:21 AM
>> >> > To: user@hbase.apache.org
>> >> > Subject: Re: Newbie question
>> >> >
>> >> > Hi Gayatri,
>> >> >
>> >> >              I am myself quite new to hbase but from my little
>> >> > experience
>> >> > and from whatever I have read, HBase is more suitable for environments
>> >> > with
>> >> > high read and write, but very few updates and no real deletions. It
is
>> >> > more
>> >> > of a write once and forget kind of database. Cassandra or MongoDB
>> might
>> >> > be
>> >> > more suitable for your requirement imo. My advice would be to consider
>> >> > those
>> >> > as well before making any decision.
>> >> >
>> >> > thanks,
>> >> > hari
>> >> >
>> >> > On Fri, Nov 12, 2010 at 7:00 PM, Gayatri Rao <rgayatri1@gmail.com>
>> >> > wrote:
>> >> >
>> >> > > Hi All,
>> >> > >
>> >> > > I am new to hbase. I have been reading up documentation and studying
>> >> > how
>> >> > > hbase suits to our requirement.
>> >> > >
>> >> > > We want to be able to store a key and corresponding values. However,
>> >> > while
>> >> > > reading, i want to read values in sorted order something like
the
>> >> > topN. Its
>> >> > > a web facing environment and our requirement is write heavy infact
>> >> > they are
>> >> > > updates of the already existing records (about 270K updates in
an
>> >> > hour
>> >> > > though actual data that needs to be stored in it might be much
much
>> >> > more).
>> >> > > Deletes would be in the order of a few thousands every day.
>> >> > >
>> >> > > I wanted to find out know your opinions on how good is hbase for
>> this
>> >> > kind
>> >> > > of scenario.
>> >> > >
>> >> > > Thanks,
>> >> > > Gayatri
>> >> > >
>> >>
>> >
>>
>

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