On Tue, Jun 22, 2010 at 09:59, David Boxenhorn <da...@lookin2.com> wrote: > In my system, I have a Cassandra front end, and an Oracle back end. Some > information is created in the back end, and pushed out to the front end, and > some information is created in the front end and pulled into the back end. > > Question: How do I locate new rows that have been crated in Cassandra, for > import into Oracle? > > I'm thinking of having a special column family "newRows" that contains only > the keys of the new rows. The offline process would look there to see what's > new, then delete those rows. The "newRows" CF would have no data! (The data > would be in the "real" CF.)
I've never tried an empty row, but I'm pretty sure you need at least one column. > > Is this a good solution? It seems weird to have a CF with rows but no data. > But I can't think of a better way. > > Any thoughts? Another approach would be to have a CF with a single row whose column names refer to the new row ids. This would allow you efficient slicing. The downside is that you'd need to make sure the row doesn't get too wide. So depending on your throughput and application behavior, this may or may not work. Gary.
