"David G. Johnston" <david.g.johnston@xxxxxxxxx> writes: > On Friday, September 3, 2021, Philippe Doussot <philippe.doussot@xxxxxxx> > wrote: >> I don't understand why disabling all index from the table speed up the >> update because the boolean column is not indexed > Index entries point to physical records. You just deleted one physical > record and added another. The indexes need to be updated with that > information. Yeah. The OP's mental model is apparently update-in-place, but that's not how Postgres does things. The index-update overhead is avoided if the update is "HOT", which requires that (a) no indexed column changes and (b) there is room on the same page for the new copy of the row. Ensuring (b) requires running with a fairly low fill-factor, which bloats your table and thereby creates its own costs. Still, that might be worth doing depending on your particular circumstances. regards, tom lane
