When data is first written it does remain in memory until that memory is
flushed. After the data is only on disk, it remains there until a read
for that row-key/column is requested so in essense it's always load on
demand.
Currently there is no support for async notifications of changes.
On 08/12/2012 03:24 PM, Oliver Plohmann wrote:
Hello,
I'm looking a bit into Cassandra to see whether it would be something
to go with for my company. I searched through the Internet, looked
through the FAQs, etc. but there are still some few open questions.
Hope I don't bother anybody with the usual beginner questions ...
Is there a way to do load-on-demand of data in Cassandra? For the time
being, we cannot afford to built up a cluster that holds our 700 GB
SQL-Database in RAM. So we need to be able to load data on-demand from
our relational database. Can this be done in Cassandra? Then there
also needs to be a way to unload data in order to reclaim RAM space.
Would be nice if it were possible to register for an asynchronous
notification in case some value was changed. Can this be done?
Thanks for any answers.
Regards, Oliver
