Hi Shen, The row refers to the ability for a DoFn in a ParDo to access per-key (and window) state cells that persist beyond the lifetime of an element or bundle. This is a feature that was in the later stages of design when the Beam code was donated. Hence it a row in the graph, but even the Beam Model column says "no", pending a public design proposal & consensus. Most runners already have a similar capability at a low level; this feature refers to exposing it in a nice way for users.
I have a design doc that I'm busily revising to make sense for the whole community. I will send the doc to this list and add it to our technical docs folder as soon as I can get it ready. You can follow BEAM-25 [1] if you like, too. Kenn [1] https://issues.apache.org/jira/browse/BEAM-25 On Fri, Jun 24, 2016 at 10:56 AM, Shen Li <cs.she...@gmail.com> wrote: > Hi, > > There is a "Keyed State" row in the "What is being computed" section of > the capability matrix. What does the "Keyed State" refer to? Is it a global > key-value store? > > ( > > http://beam.incubator.apache.org/beam/capability/2016/03/17/capability-matrix.html > ) > > Thanks, > > Shen >
