Let me rephrase: The *majority* of the literature, of which I cited just one example, calls them punctuation, and a couple of recent papers out of Mountain View doesn't change that. There are some fine distinctions between punctuation, heartbeats, watermarks and rowtime bounds, mostly in terms of how they are generated and propagated, that matter little when planning the query. On Fri, Feb 5, 2016 at 5:18 PM, Ted Dunning wrote: > On Fri, Feb 5, 2016 at 5:10 PM, Julian Hyde wrote: > >> Yes, watermarks, absolutely. The "to do" list has "punctuation", which >> is the same thing. (Actually, I prefer to call it "rowtime bound" >> because it is feels more like a dynamic constraint than a piece of >> data, but the literature[1] calls them punctuation.) >> > > Some of the literature calls them punctuation, other literature [1] calls > them watermarks. > > [1] http://www.vldb.org/pvldb/vol8/p1792-Akidau.pdf