i know it's a throwaway example, but i would probably structure your
column the other way around in that case.
ie steve.4, steve.5, steve.6, greg.4, greg.6, greg.9.
and then do two slice queries, steve.4-steve.10, greg.4-greg.10.
On 04/01/2012 15:41, Jeremiah Jordan wrote:
You can't use a slice range. But you can query for the specific
columns. "4.steve", "5.steve", "6.steve" ... "4.greg", "5.greg",
"6.greg". Just have to ask for all of the possible columns you want.
On 01/03/2012 04:31 PM, Stephen Pope wrote:
The bonus you're talking about here, how do I apply that?
For example, my columns are in the form of 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]
Sent: Tuesday, January 03, 2012 3:12 PM
To: 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.)
