On Sun, 2024-07-14 at 00:05 +0200, Peter J. Holzer wrote: > On 2024-07-11 10:06:47 +0200, Laurenz Albe wrote: > > On Thu, 2024-07-11 at 13:10 +0530, sud wrote: > > > Dropping will take it's own time for post vacuum however as you > > > rightly said, it won't be blocking which should be fine. > > > > I am not certain if you understood this correctly. > > > > Dropping a column is fast, but doesn't reclaim the space. > > VACUUM won't block anything, but won't reclaim the space. > > VACUUM (FULL) will block everything, but will also not reclaim the space. > > > > You'd need to use a form of ALTER TABLE that rewrites the table, > > as indicated in the documentation. > > Unfortunately the documentation indicates very little. It mentions that > the table will be rewritten with > > * SET ACCESS METHOD > * a volatile DEFAULT > * changing the type of an existing column (unless binary coercible) > > All three change something which you probably don't want to change. Hm, true. You can always do UPDATE tab SET id = id; followed by VACUUM (FULL) tab; Yours, Laurenz Albe
