cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jeremiah Jordan <>
Subject Re: Replacing supercolumns with composite columns; Getting the equivalent of retrieving a list of supercolumns by name
Date Wed, 04 Jan 2012 15:43:48 GMT
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".


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 < 
> <>> wrote:
>      The bonus you're talking about here, how do I apply that?
>      For example, my columns are in the form of
>     <> such as 4.steve, 4.greg, 5.steve, 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 [
>     <>]
>     Sent: Tuesday, January 03, 2012 3:12 PM
>     To: <>
>     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.)

View raw message