Oops, typo: I reversed the inequality. I've corrected it below. On Friday February 23 2007 2:02 pm, Ed L. wrote: > I've been periodically collecting the stats stored in > pg_statio_all_tables and pg_stat_database for ~30 different > clusters, and have noticed a curiosity. > > I would have thought that for a given period, the change in > pg_stat_database.blks_read would be >= the sum of the changes > in pg_statio_user_tables.heap_blks_read + > pg_statio_user_tables.idx_blks_read + > pg_statio_user_tables.toast_blks_read + > pg_statio_user_tables.tidx_blks_read. > > In short, the total would be >= heap + idx + toast + idx for > user tables. > > It does not appear that way. The table-level IO stats appear > to be typically 1-2 orders of magnitude larger than the > db-level stats. Can anyone explain that? > > TIA. > Ed
