On Tue, 2023-02-07 at 12:40 -0600, Ron wrote: > > "The DROP COLUMN form does not physically remove the column, but simply > > makes it > > invisible to SQL operations. Subsequent insert and update operations in the > > table > > will store a null value for the column. Thus, dropping a column is quick > > but it > > will not immediately reduce the on-disk size of your table, as the space > > occupied > > by the dropped column is not reclaimed. The space will be reclaimed over > > time as > > existing rows are updated. > > > > To force immediate reclamation of space occupied by a dropped column, you > > can > > execute one of the forms of ALTER TABLE that performs a rewrite of the > > whole table. > > This results in reconstructing each row with the dropped column replaced by > > a > > null value." > > VACUUM FULL doesn't rewrite the table?
It rewrites the table, but it just copies rows rather than reconstructing them. Yours, Laurenz Albe
