Hi, I see "The CompareWith attribute tells Cassandra how to sort the columns for slicing operations." on wiki ( http://wiki.apache.org/cassandra/StorageConfiguration). So the CompareWith defines how to sort column (or super-columns) in scope of one row. So this option is relate to (multi)get_slice operation.
I'm not sure if you can retrieve sorted rows. The only way how to get more rows is "get_range_slices" method (and "get_indexed_slices") and there is no sorting. Augi 2011/2/18 cbert...@libero.it <cbert...@libero.it> > Hi all, > I created a CF in which i need to get, sorted by time, the Rows inside. > Each > Row represents a comment. > > <ColumnFamily name="Comments" compareWith="TimeUUIDType" / > > > I've created a few rows using as Row Key a generated TimeUUID but when I > call > the Pelops method "GetColumnsFromRows" I don't get the data back as I > expect: > rows are not sorted by TimeUUID. > I though it was probably cause of the random-part of the TimeUUID so I > create > a new CF ... > > <ColumnFamily name="Comments2" compareWith="LongType" / > > > This time I created a few rows using the java System.CurrentTimeMillis() > that > retrieve a long. I call again the "GetColumnsFromRows" and again the same > results: data are not sorted! > I've read many times that Rows are sorted as specified in the compareWith > but > I can't see it. > To solve this problem for the moment I've used a SuperColumnFamily with an > UNIQUE ROW ... but I think this is just a workaround and not the solution. > > <ColumnFamily name="Comments" type="Super" compareWith="TimeUUIDType" > CompareSubcolumnsWith="BytesType"/ > > > Now when I call the "GetSuperColumnsFromRow" I get all the SuperColumns as > I > expected: sorted by TimeUUID. Why it does not happen the same with the > Rows? > I'm confused. > > TIA for any help. > > Best Regards > > Carlo >
