hello, got something strange to me: Same db ie. same data, around 1.2TB,one on pg13, one on pg16 same 16 GB of shared_buffers, I am the single user. both have track_io_timing on
on pg13, if I run a big request with explain (analyze,buffers), I see around 6 GB read if I do rerun the very same request, no more read(s), all data in the shared buffers cache. fine If I check with pg_buffercache what's in it, I see the biggest tables of my request within the biggest users (in number of blocks used). All this is fine. next, if I do the very same on the pg16 machine, whatever the number of times I rerun the explain (analyze, buffers) of the same request, each time, the explain shows the same volume of reads. again and again. If I check with pg_buffercache, the set of objects stay the same, WITHOUT the objects of my request, just like if those objects where sticky. any idea ? thanks Marc MILLAS Senior Architect +33607850334 www.mokadb.com
