Robert Haas <robertmh...@gmail.com> writes: > On Fri, Jul 15, 2016 at 4:28 AM, Craig Ringer <cr...@2ndquadrant.com> wrote: >> I don't think anyone's considering moving from multi-processing to >> multi-threading in PostgreSQL. I really, really like the protection that the >> shared-nothing-by-default process model gives us, among other things.
> We get some very important protection by having the postmaster in a > separate address space from the user processes, but separating the > other backends from each other has no value. I do not accept that proposition in the least. For one thing, debugging becomes an order of magnitude harder when you've got multiple threads in the same address space: you have essentially zero guarantees about what one thread might have done to the supposedly-private state of another one. > ... enough other people have > written complex, long-running multithreaded programs that I think it > is probably possible to do so without unduly compromising reliability. I would bet that every single successful project of that sort has been written with threading in mind from the get-go. Trying to retro-fit threading onto thirty years' worth of single-threaded coding is a recipe for breaking your project; even if you had control of all the code running in the address space, which we assuredly do not. regards, tom lane -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers