In each family, both CF and SCF, data are grouped by rows.
Just to give an idea ...
Super Column Family Name{
Row 1 {
SuperColumn1 { Column1 Key: Column1 Value ... ColumnN Key:
ColumnN Value}
SuperColumn2 { Column1 Key: Column1 Value, ColumnN Key:
ColumnN Value}
}
Row N {
SuperColumn1 { Column1 Key: Column1 Value ... ColumnN Key:
ColumnN Value}
SuperColumn2 { Column1 Key: Column1 Value ... ColumnN Key:
ColumnN Value}
SuperColumn3 { Column1 Key: Column1 Value ... ColumnN Key:
ColumnN Value}
}
}
Column Family Name {
Row1 {
Column1 Key: Column1 Value
.....
ColumnN Key: ColumnN Value
}
RowN {
Column1 Key: Column1 Value
.....
ColumnN Key: ColumnN Value
}
}
Your representation looks like a SCF ...
detailed_log: { // supercolumnfamily
username : { // row
uuid // supercolumn identifier {
{ price : 100 } // column price
{ min : 10 } column min
{ max : 500 }, // column max
}
uuid // supercolumn identifier {
{ price : 100 } // column price
{ min : 10 } column min
{ max : 500 }, // column max
}
}
}
detailed_log can contains from 0 to N rows and each row can contain from 0 to
N SuperColumns. Each SuperColumn can contain from 0 to N columns.
>SELECT * FROM detailed_log WHERE username = 'foobar' AND uuid RANGE(
>start_UUID -> end_UUID );
I would say in Pelops (java) Client i Use is something like this ...
.... getSuperColumnsFromRow(/**
* Retrieve super columns from a row
* @param rowKey The key of the row
* @param columnFamily The name of the column family
containing the super columns
* @param colPredicate The super column selector
predicate
* @param cLevel The Cassandra consistency level
with
which to perform the operation
* @return A list of matching columns
*/)
List<SuperColumn> result = selector.getSuperColumnsFromRow(username,"
detailed_log", Selector.newColumnsPredicateAll(false, howmany),
ConsistencyLevel.ONE);
This will retrieve "howmany" SuperColumns, sorted by your Storage Conf sorting
definition, from the row username.
Hope this helps.
Best Regards
Carlo
