On Wed, Jun 13, 2012 at 9:08 PM, Greg Fausak <g...@named.com> wrote: > Interesting. > > How do you do it? > > I have a version 2 CF, that works fine. > A version 3 table won't let me invent columns that > don't exist yet. (for composite tables). What's the trick? >
You are able to get the same behaviour as non cql by doing something like this: CREATE TABLE mytable ( id bigint, name text, value text, PRIMARY KEY (id, name) ) WITH COMPACT STORAGE; This table will work exactly like a standard column family with no defined columns. For example: cqlsh:testing> INSERT INTO mytable (id, name, value) VALUES (1, 'firstname', 'Alice'); cqlsh:testing> INSERT INTO mytable (id, name, value) VALUES (1, 'email', ' al...@example.org'); cqlsh:testing> INSERT INTO mytable (id, name, value) VALUES (2, 'firstname', 'Bob'); cqlsh:testing> INSERT INTO mytable (id, name, value) VALUES (2, 'webpage', ' http://bob.example.org'); cqlsh:testing> INSERT INTO mytable (id, name, value) VALUES (2, 'email', ' b...@example.org'); cqlsh:testing> SELECT name, value FROM mytable WHERE id = 2; name | value -----------+------------------------ email | b...@example.org firstname | Bob webpage | http://bob.example.org Not very exciting, but when you take a look with cassandra-cli: [default@testing] get mytable[2]; => (column=email, value=b...@example.org, timestamp=1339648270284000) => (column=firstname, value=Bob, timestamp=1339648270275000) => (column=webpage, value=http://bob.example.org, timestamp=1339648270280000) Returned 3 results. Elapsed time: 11 msec(s). which is exactly what you would expect from a normal cassandra column family. So the trick is to separate your static columns and your dynamic columns into separate column families. Column names and types can of course be something different then my example, and inserts can be done within a 'BATCH' to avoid multiple round trips. Also, I'm not trying to advocate this as being a better solution then just using the old thrift interface, I'm just showing an example of how to do it. I personally do prefer this way as it is more predictable, but of course others will have a different opinion. -- Derek Williams
