1. Data Modeling In Cassandra Jahangir Mohammed md.jahangir27@gmail.com
2. ELEMENTS Keyspace: Like Database. Container for CFs. Column Family: Like Table(But, not exactly a relational database table). Container of rows. Row: Sorted collection of columns. Column: Basic unit of data structure. Triplet of name, value and timestamp.
3. ELEMENTS Super Column: Special column. Sorted associative array of columns. Map of maps. Only one level deep. Super Column Family: Container of rows having super columns. 4-D DHT = Standard CF: [Keyspace][ColumnFamily][Key][Column]. 5-D DHT = Super CF: [Keyspace][ColumnFamily][Key][SuperColumn][SubColumn].
4. elements Composite key: Composite Key name(e.g. <systemid:time>). Subcolumns inside supercolumn are not indexed. May be used when 10’s of thousands of subcolumns. Valueless column: Column’s name is the value and value is empty.
5. ROWS Skinny Rows: Small number of columns. Like RDBMS rows. Optional columns(schema less design). Wide Rows: Loads of columns. Typically monitoring applications or time series data. Column Sorting.
