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From Ted Zlatanov <...@lifelogs.com>
Subject Re: Cassandra users survey
Date Tue, 24 Nov 2009 14:32:45 GMT
On Mon, 23 Nov 2009 23:30:51 -0500 Matt Revelle <mrevelle@gmail.com> wrote: 

MR> Are you both using timestamps as row keys?  Would be great to hear
MR> more details.

I'm using super column keys in a super column.

So let's say your resource is "routerA."

Your data will be:

Row "routerA"
 SuperColumn "Status"
  SuperColumn key T0 (this morning)
   Columns { status: connected, location: USA, ... }
  SuperColumn key T1 (T0 + 10 seconds for example)
   Columns { status: disconnected, location: Europe, ... }
  SuperColumn key T2 (T1 + 10 seconds for example)
   Columns { status: connected, ... } // no location specified

Then you can say "give me the latest super column key" (limit = 1, 
order = reversed, start == end == 0) and you'll get T1.

Ted


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