Derek, Thanks for that!
Yes, I am aware of that technique. I am currently using something very similar on an sql database. I think one of the great benefits with Cassandra is that you can invent these on the fly. I also think there is great benefit to keep all of the columns in the same row. Anyway, I didn't mean to hijack Oleg's thread. I am interested in the original question about the serialization/deserialization on write. Does anybody know? -g On Wed, Jun 13, 2012 at 11:45 PM, Derek Williams <de...@fyrie.net> wrote: > 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 >
