I execute the command sync && echo 3 > /proc/sys/vm/drop_caches but I still got buffers hit added to that buffers read now.Why I got the buffers hit?
2017-11-24 17:55 GMT+01:00 Tom Lane <t...@sss.pgh.pa.us>: > bricklen <brick...@gmail.com> writes: > > On Fri, Nov 24, 2017 at 6:54 AM, hmidi slim <hmidi.sl...@gmail.com> > wrote: > >> I'm trying to analyze some queries using the explain instructions and > the > >> option analyze and buffers. I realized that the query refers to the > cache > >> memory to return the results. Is there any solution to clear the cache > in > >> postgresql inorder to get execution time of the query when it get data > from > >> disk and not from cache memory? > > > If you are on a (non-production) *nix server you can use: > > sync && echo 3 > /proc/sys/vm/drop_caches > > You would also need to restart the postmaster, to get rid of whatever > is in Postgres' shared buffers. > > regards, tom lane >
