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Accumulo, mail # dev - Re: [jira] [Commented] (ACCUMULO-227) Improve in memory map counts to provide cell level uniqueness for repeated columns in mutation


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Re: [jira] [Commented] (ACCUMULO-227) Improve in memory map counts to provide cell level uniqueness for repeated columns in mutation
Aaron Cordova 2011-12-22, 21:04

On Dec 22, 2011, at 4:00 PM, Adam Fuchs wrote:

> Timestamp doesn't usually make
> it into the uniqueness concept, from a user's perspective, even though that
> affects the sort order of Keys. In fact, most users let Accumulo set the
> timestamp for them. I think your definition of uniqueness takes timestamp
> into account, and from that perspective what we're doing is sort of like
> providing a finer grained timestamp instead of using one timestamp for an
> entire Mutation (or for all Mutations that show up within a millisecond).

Timestamps do define separate keys. This is not just my definition - this is in the BigTable design as well as Hbase's, and likely every other BigTable clone.