On 11/12/24 11:37, Achilleas Mantzios - cloud wrote: > > ... > > We run perf on both systems for 90 seconds to make sure that it included > at least two runs of the slow system, and we attach both outputs. We run > perf as : > > sudo perf record -g -p <PID> -- sleep 90 > > it strikes me that we dont find similarities between the two, but we are > new to perf. > Not sure, but it seems the slow profile has a lot of writes. Not sure why. Do both instances have the same work_mem value / available memory, storatge? Maybe EXPLAIN VERBOSE would show if the remote query is the same ... Maybe try setting log_temp_files=0 before running the query. Writing the foreign scan result set into a temp file could be happening on one of the machines only. regards -- Tomas Vondra
