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From Konstantin Boudnik <...@apache.org>
Subject Re: Timestamp resolution
Date Sat, 24 May 2014 00:58:24 GMT
What's the purpose of nanos accuracy in the TS? I am trying to think of one,
but I don't know much about real production use cases.


P.S. Are you saying that a real concern is how usable Hbase will be in
nearly 300 years from now? ;) Or I misread you? 

On Fri, May 23, 2014 at 05:27PM, lars hofhansl wrote:
> We have discussed this in the past. It just came up again during an internal discussion.
> Currently we simply store a Java timestamp (millisec since epoch), i.e. we have ms resolution.
> We do have 8 bytes for the TS, though. Not enough to store nanosecs (that
> would only cover 2^63/10^9/3600/24/365.24 = 292.279 years), but enough for
> microseconds (292279 years).
> Should we just store he TS is microseconds? We could do that right now (and
> just keep the ms resolution for now - i.e. the us part would always be 0 for
> now).
> Existing data must be in ms of course, so we'd grandfather that in, but new
> tables could store by default in us.
> We'd need to make this configurable both the column family level and client
> level, so clients could still opt to see data in ms.
> Comments? Too much to bite off?
> -- Lars

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