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From Geoffry Roberts <geoffry.robe...@gmail.com>
Subject Re: ORM in Cassandra?
Date Mon, 26 Apr 2010 15:32:20 GMT
I am going to agree with axQd. Having something that does for Cassandra what
say, Hibernate does for RDBMS seems an effort well worth pursuing.  I have
some complex object graphs written in Java.  If I could annotate them and
get persistence with a well laid out schema. It would be good.

On Mon, Apr 26, 2010 at 8:21 AM, Schubert Zhang <zsongbo@gmail.com> wrote:

> I think you should forget these RDBMS tech.
>
>
>
> On Sat, Apr 24, 2010 at 11:00 AM, aXqd <axqd001@gmail.com> wrote:
>
>> On Sat, Apr 24, 2010 at 1:36 AM, Ned Wolpert <ned.wolpert@imemories.com>
>> wrote:
>> > There is nothing wrong with what you are asking. Some work has been done
>> to
>> > get an ORM layer ontop of cassandra, for example, with a RubyOnRails
>> > project. I'm trying to simplify cassandra integration with grails with
>> the
>> > plugin I'm writing.
>> > The problem is ORM solutions to date are wrapping a relational database.
>> > (The 'R' in ORM) Cassandra isn't a relational database so it does not
>> map
>> > cleanly.
>>
>> Thanks. I noticed this problem before. I just want to know, in the
>> first place, what exactly is the right way to model relations in
>> Cassandra(a no-relational database).
>> So far, I still have those entities, and, without foreign keys, I use
>> relational entities, which contains the IDs of both sides of
>> relations.
>> In some other cases, I just duplicate data, and maintain the relations
>> manually by updating all the data in the same time.
>>
>> Is this the right way to go? Or what I am doing is still trying to
>> convert Cassandra to a RDBMS?
>>
>> >
>> > On Fri, Apr 23, 2010 at 1:29 AM, aXqd <axqd001@gmail.com> wrote:
>> >>
>> >> On Fri, Apr 23, 2010 at 3:03 PM, Benoit Perroud <benoit@noisette.ch>
>> >> wrote:
>> >> > I understand the question more like : Is there already a lib which
>> >> > help to get rid of writing hardcoded and hard to maintain lines like
>> :
>> >> >
>> >> > MyClass data;
>> >> > String[] myFields = {"name", "label", ...}
>> >> > List<Column> columns;
>> >> > for (String field : myFields) {
>> >> >    if (field == "name") {
>> >> >       columns.add(new Column(field, data.getName()))
>> >> >    } else if (field == "label") {
>> >> >      columns.add(new Column(field, data.getLabel()))
>> >> >    } else ...
>> >> > }
>> >> > (same for loading (instanciating) automagically the object).
>> >>
>> >> Yes, I am talking about this question.
>> >>
>> >> >
>> >> > Kind regards,
>> >> >
>> >> > Benoit.
>> >> >
>> >> > 2010/4/23 dir dir <sikerasakti@gmail.com>:
>> >> >>>So maybe it's weird to combine ORM and Cassandra, right? Is
there
>> >> >>>anything we can take from ORM?
>> >> >>
>> >> >> Honestly I do not understand what is your question. It is clear
that
>> >> >> you can not combine ORM such as Hibernate or iBATIS with Cassandra.
>> >> >> Cassandra it self is not a RDBMS, so you will not map the table
into
>> >> >> the object.
>> >> >>
>> >> >> Dir.
>> >>
>> >> Sorry, English is not my mother tongue.
>> >>
>> >> I do understand I cannot combine ORM with Cassandra, because they are
>> >> totally different ways for building our data model. But I think there
>> >> are still something can be learnt from ORM to make Cassandra easier to
>> >> use, just as what ORM did to RDBMS before.
>> >>
>> >> IMHO, domain model is still intact when we design our software, hence
>> >> we need another way to map them to Cassandra's entity model. Relation
>> >> does not just go away in this case, hence we need another way to
>> >> express those relations and have a tool to set up Keyspace /
>> >> ColumnFamily automatically as what django's SYNCDB does.
>> >>
>> >> According to my limited experience with Cassandra, now, we do more
>> >> when we write, and less when we read/query. Hence I think the problem
>> >> lies exactly in how we duplicate our data to do queries.
>> >>
>> >> Please correct me if I got these all wrong.
>> >>
>> >> >>
>> >> >> On Fri, Apr 23, 2010 at 12:12 PM, aXqd <axqd001@gmail.com>
wrote:
>> >> >>>
>> >> >>> Hi, all:
>> >> >>>
>> >> >>> I know many people regard O/R Mapping as rubbish. However it
is
>> >> >>> undeniable that ORM is quite easy to use in most simple cases,
>> >> >>> Meanwhile Cassandra is well known as No-SQL solution, a.k.a.
>> >> >>> No-Relational solution.
>> >> >>> So maybe it's weird to combine ORM and Cassandra, right? Is
there
>> >> >>> anything we can take from ORM?
>> >> >>> I just hate to write CRUD functions/Data layer for each object
in
>> even
>> >> >>> a disposable prototype program.
>> >> >>>
>> >> >>> Regards.
>> >> >>> -Tian
>> >> >>
>> >> >>
>> >> >
>> >
>> >
>> >
>> > --
>> > Virtually, Ned Wolpert
>> >
>> > "Settle thy studies, Faustus, and begin..."   --Marlowe
>> >
>>
>
>

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