hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jon Schutz <Jon.Sch...@youramigo.com>
Subject TTL, Versions and storing long history
Date Tue, 30 Jun 2009 02:21:58 GMT

How do TTL and Versions specifications interact?  I'm guessing that the
first limit reached applies, i.e. if TTL is 1 week and versions is 3,
adding a fourth update to a data record would cause the first to be
bumped even if it is less than a week old?  And if I only have 2
versions but one is 2 weeks old, the expired one gets bumped even though
the versions limit has not been reached?

Is there a way to say "Keep versions < x weeks old, but always keep at
least the latest version, no matter how old?"

Suppose I want to keep the history about a particular object forever.
Looks like TTL can be set to 'Forever' (-1) but Versions has no
'infinite' setting - I guess that's OK as in practice MAXINT is "big
enough".  Would it be wise to use Hbase like this to maintain a history,
or should I be adding a time component into the key and storing multiple
records?  Can anyone help outline the pros and cons?


Jon Schutz                        My tech notes http://notes.jschutz.net
Chief Technology Officer                        http://www.youramigo.com

View raw message