On Monday, December 20, 2021, Tom Lane <t...@sss.pgh.pa.us> wrote: > Justin Pryzby <pry...@telsasoft.com> writes: > > On Mon, Dec 20, 2021 at 08:11:42PM -0800, Lars Bergeson wrote: > >> Still taking 10X more I/O to read the smaller table. Very odd. > > > If I'm not wrong, it's even worse than that ? > > It takes 20 or 30sec to run the query - but it says the associated I/O > times > > are ~500sec or ~6000sec ? > > It would help if somebody had labeled the units of I/O Time > ... but I'm guessing those are microsec vs. the millisec > of the other times, because otherwise it's completely wrong. > > Related to my preceding observation, from the explain (buffers) docs:
“…and the time spent reading and writing data file blocks (in milliseconds) if track_io_timing <https://www.postgresql.org/docs/current/runtime-config-statistics.html#GUC-TRACK-IO-TIMING> is enabled.“ David J.
