Hello
Please recheck with track_io_timing = on in configuration. explain (analyze,buffers) with this option will report how
manytime we spend during i/o
> Buffers: shared hit=2 read=31492
31492 blocks / 65 sec ~ 480 IOPS, not bad if you are using HDD
Your query reads table data from disks (well, or from OS cache). You need more RAM for shared_buffers or disks with
betterperformance.
regards, Sergei