On Sat, Oct 27, 2018 at 6:10 AM Thomas Kellerer <spam_eater@xxxxxxx> wrote: > Jeff Janes schrieb am 26.10.2018 um 17:42: > > I typically configure "shared_buffers = 4096MB" on my 16GB system as sometimes when testing, it pays off to have a bigger cache. > > > > With Postgres 10 and earlier, the Postgres process(es) would only allocate that memory from the operating system when needed. > > So right after startup, it would only consume several hundred MB, not the entire 4GB > > > > However with Postgres 11 I noticed that it immediately grabs the complete memory configured for shared_buffers during startup. > > > > It's not really a big deal, but I wonder if that is an intentional change or a result from something else? > > > > > > Do you have pg_prewarm in shared_preload_libraries? > > No. The only shared libraries are those for pg_stat_statemens Does your user have "Lock Pages in Memory" privilege? One thing that is new in 11 is huge AKA large page support, and the default is huge_pages=try. Not a Windows person myself but I believe that should succeed if you have that privilege and enough contiguous chunks of physical memory are available. If you set huge_pages=off does it revert to the old behaviour? -- Thomas Munro http://www.enterprisedb.com
