Postgresql 9.6: Support parallel aggregation

>> I am interested in possibly switching at some point if it's worthwhile

> If you aren't using it now, and thus don't know how fast or slow it would be on your data and queries, why would you care about percentage speed ups?

I'm working under the assumption that similar operations between PostgreSQL and MySQL for operations that aren't using an advanced feature that the other plainly doesn't support will be roughly comparable in performance. I understand this isn't true, but it's useful in that it gives me a baseline to work with when reasoning without forcing me to migrate my application (or at least a significant portion of the data) to PostgreSQL just to test. If I'm then confronted with a feature that one supports and the other doesn't that has the capability to in some cases reduce the query time by an order of magnitude, then it's starts approaching the criteria needed for me to invest that time to see if it's worth migrating.

> I gather that people considering migrating who want some reassurance before investing time in testing should be more interested in such things things as benchmarks that show whether PostgreSQL can saturate your hardware for various query types

Isn't that exactly what this is? Throwing CPU cores at aggregating data to reduce time? I asked for benchmarks regarding this specific feature, to see what type of gain we were talking about with this. I didn't ask for comparisons to other databases because those benchmarks are generally harder to perform fairly, so I would have been (and am) happy with comparative gain benchmarks.

I really do wonder whether there's a verified "path of trust" where I can get a copy of e.g. Debian (without knowing what the canonical website for Debian is), install it on a machine, connect it to the internet and update it, without being at all vulnerable to a MitM attack at any step.

I would be suspicious that it's the very first step that poses the most danger: there's little way to know whether minor-distro-X is "properly" hosted at minordistrox.com or distrox.org or even distrox.github.io, other than by blindly trusting the relative PageRanks of each.

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Something that would be very nice, I think, would be a way to rely on the package-signing infrastructure of the OS you've already got (and trust), to guarantee for you the copies of any new OS images—even for different OSes!—you download. Sort of the same way you download new versions of OSX through the Mac App Store, but going a bit further.

Now that I think about it, the browser-preloaded HSTS list might do the trick... if it was coupled with a mapping of 'important well-known downloads' to a single (HSTS-preloaded) domain you should be allowed to get those downloads from. (Presumably with heuristic detection, so it could find "something looking mostly, from its metadata, like a Debian ISO image.") Then your browser would just tell you you're being phished if you're trying to get a Debian ISO from debianisamazing.info.