Unless you are running into an issue with using super columns that make
the composite columns better fit what you are trying to do, I would just
stick with super-columns. "if it ain't broke don't fix it".
-Jeremiah
On 01/03/2012 11:21 PM, Asil Klin wrote:
@Stephan: in that case, you can easily tell the names of all columns
you want to retrieve, so you can make a query to retrieve those list
of composite columns.
@Jeremiah,
So where is my best bet ? Should I leave the supercolumns as it is as
of now, since I can find a good way to use them incase I replace them
with composite columns?
On Wed, Jan 4, 2012 at 4:01 AM, Stephen Pope <stephen.p...@quest.com
<mailto:stephen.p...@quest.com>> wrote:
The bonus you're talking about here, how do I apply that?
For example, my columns are in the form of number.id
<http://number.id> such as 4.steve, 4.greg, 5.steve, 5.george. Is
there a way to query a slice of numbers with a list of ids? As in,
I want all the columns with numbers between 4 and 10 which have
ids steve or greg.
Cheers,
Steve
-----Original Message-----
From: Jeremiah Jordan [mailto:jeremiah.jor...@morningstar.com
<mailto:jeremiah.jor...@morningstar.com>]
Sent: Tuesday, January 03, 2012 3:12 PM
To: user@cassandra.apache.org <mailto:user@cassandra.apache.org>
Cc: Asil Klin
Subject: Re: Replacing supercolumns with composite columns;
Getting the equivalent of retrieving a list of supercolumns by name
The main issue with replacing super columns with composite columns
right now is that if you don't know all your sub-column names you
can't select multiple "super columns" worth of data in the same
query without getting extra stuff. You have to use a slice to get
all subcolumns of a given super column, and you can't have
disjoint slices, so if you want two super columns full, you have
to get all the other stuff that is in between them, or make two
queries.
If you know what all of the sub-column names are you can ask for
all of the super/sub column pairs for all of the super columns you
want and not get extra data.
If you don't need to pull multiple super columns at a time with
slices like that, then there isn't really an issue.
A bonus of using composite keys like this, is that if there is a
specific sub column you want from multiple super columns, you can
pull all those out with a single multiget and you don't have to
pull the rest of the columns...
So there are pros and cons...
-Jeremiah
On 01/03/2012 01:58 PM, Asil Klin wrote:
> I have a super columns family which I always use to retrieve a
list of
> supercolumns(with all subcolumns) by name. I am looking forward to
> replace all SuperColumns in my schema with the composite columns.
>
> How could I design schema so that I could do the equivalent of
> retrieving a list of supercolumns by name, in case of using
composite
> columns.
>
> (As of now I thought of using the supercolumn name as the first
> component of the composite name and the subcolumn name as 2nd
> component of composite name.)
