Can rdd4j be used to persist Strings

I am trying to use rdd4j to persist a String but this does not seem to work.
Any idea?

Pretty sure rrd is numerical only. It is capable of doing mathematical expressions on the elements.

thanks. Jim.
What would be the best way to persist a string or a datetype when rrd4j is not suited?

If you don’t require historical values, then mapdb persistence will work. I use this so stuff is restored correctly upon startup.

Thanks for the advice. Mark.

Does the mapdb persistance store grow over the time or does it also have the nice feature of rdd4j to stay constant?

No; it only stores the last value and won’t grow over time.

@watou, thanks for the support

Hi Martin,

Based on your question, I just made a major update to the Persistence wiki page that now includes a big table of available persistence options, including documentation and external links, whether the service supports queries, and other notes about the service. This should provide better guidance about the available persistence options. Please have a look!


This table is really a valuable enhancement of the documentation.
Thanks for you effort.

cheers Martin

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