and by Fucsh I mean Fuchs of course .. On Dec 22, 2011, at 4:22 PM, Aaron Cordova wrote:
> by "byte pairs" I mean byte arrays .. of course ... > > On Dec 22, 2011, at 4:20 PM, Aaron Cordova wrote: > >> _You_ can think of it that way, cause you're Adam Fucsh, distributed >> database expert extraordinaire, but that's not how the BigTable data model >> was described by the original authors - "BigTable is a sparse, sorted, >> distributed, multidimensional map", and most users do understand Accumulo to >> be a map of keys to values where the keys are made up of a row, colfam, >> colqual, colvis, and timestamp and the values are arbitrary byte pairs. >> >> To start explaining to people that Accumulo is a multi-map, or to actually >> make it into a multi-map (i.e. allowing identical keys, where a key includes >> the timestamp), would be a mistake, in my opinion. >> >> >> On Dec 22, 2011, at 4:09 PM, Adam Fuchs wrote: >> >>> Sorry, I thought we were talking about users' perceptions of semantics. >>> Bigtable also supports holding multiple versions of key/value pairs, so it >>> can be thought of as having an underlying multi-map as well. >>> >>> Adam >>> >>> >>> On Thu, Dec 22, 2011 at 4:04 PM, Aaron Cordova <[email protected]> wrote: >>> >>>> >>>> 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. >>>> >>>> >>>> >> >
