On 2016-09-02 11:10:35 -0600, Scott Marlowe wrote: > On Fri, Sep 2, 2016 at 4:49 AM, dandl <da...@andl.org> wrote: > > Re this talk given by Michael Stonebraker: > > > > http://slideshot.epfl.ch/play/suri_stonebraker > > > > > > > > He makes the claim that in a modern ‘big iron’ RDBMS such as Oracle, DB2, MS > > SQL Server, Postgres, given enough memory that the entire database lives in > > cache, the server will spend 96% of its memory cycles on unproductive > > overhead. This includes buffer management, locking, latching (thread/CPU > > conflicts) and recovery (including log file reads and writes).
I think those numbers are overblown, and more PR than reality. But there certainly are some things that can be made more efficient if you don't care about durability and replication. > > I wondered if there are any figures or measurements on Postgres performance > > in this ‘enough memory’ environment to support or contest this point of > > view? I don't think that's really answerable without individual use-cases in mind. Answering that question for analytics, operational, ... workloads is going to look different, and the overheads are elsewhere. I personally think that each implementations restrictions are more likely to be an issue than anything "fundamental". > What limits postgresql when everything fits in memory? The fact that > it's designed to survive a power outage and not lose all your data. > > Stonebraker's new stuff is cool, but it is NOT designed to survive > total power failure. > > Two totally different design concepts. It's apples and oranges to compare > them. I don't think they're that fundamentally different. Greetings, Andres Freund -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
