Super columns have some limitations http://wiki.apache.org/cassandra/CassandraLimitations
it's not possible to bring back a range of super columns, as you say you can specify one or zero super column names in your ColumnParent.
You could use standard CF's, and do two reads. First one would be the Super Col part of your query below to find the first day. Second would be to get all the values for that day from one row. You can treat cassandra as an indexing building machine, and make a couple of requests to get your final data.
There are also index operations available in 07. I'm not up to date enough with them to recommend an approach.
Hope that helps.
Aaron
On 17 Nov, 2010,at 03:21 PM, E S <tr1skl...@yahoo.com> wrote:
I am going to have a supercolumn family where some rows can be quite large
(10-100 mb). I'd like to be able to pull a subset of this data without having
to pull the whole thing into memory and send it over the wire.
Each query will be for only one row. The supercolumn key and the child column
keys are going to be dates. I want to query:
"For row 123, give me all the column values whose date are between 1/1/2000 and
1/1/2005 for the first supercolumn whose date is before 1/1/2009."
Since super columns and columns are sorted by date, it seems like it should be
pretty efficient to do this in 1 query, but I can't figure out how to do this in
the API. If I knew the super column name, I could do a slicerange for the key
with the target supercolumn as parent on a range of dates (1/1/2000-1/1/2005),
but I only know that I want the first supercolumn before a date.
Thanks for any help!
