Depends on your scale, you can either code something yourself through the API or take advantage of the Hadoop integration and run jobs that read and write the data back. In either case you can change the code first to write to the new column as well as the old, then update all existing data, then change the code to read from the new field.
When you change the comparator the existing data is not migrated. Some changes are backwards compatible, e.g. moving from BytesType to any other type, AsciiType to UTF8Type, moving from LongType to IntegerType. What sort of change did you want to do? Hope that helps. ----------------- Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 10 Jun 2011, at 21:21, Artem Orobets wrote: > If my application works in production and I change structure of my data (e.g. > type of column name) > I will need to process all my stored data. > As variant I can create new column family and import legacy data. > > I think, that is typical task, so tool for doing this should exist, but I > can’t find anything. > Are there any tools or proved approaches to solve this task ?
