If you want to be able to get the data over time, you need to store it in multiple columns. You can use TimeUUID columns if you need to be able to get ranges of times through queries.
-----Original Message----- From: Maifi Khan [mailto:maifi.k...@gmail.com] Sent: Friday, August 06, 2010 2:51 PM To: user@cassandra.apache.org Subject: one question about cassandra write Hi I have a question about the internal of cassandra write. Say, I already have the following in the database - (row_x,col_y,val1) Now if I try to insert (row_x,col_y,val100), what will happen? Will it overwrite the old data? I mean, will it overwrite the data physically or will it keep both the old version and the new version of the data? If the later is the case, can I retrieve the old version of the data? One sample example where I may need this is as follows - say I want to log the stock price of a particular company over time. Say company name is the row key and stock price is the column. Then the stock price column needs to be written repeatedly. HTH thanks Maifi
