Carlos Benkendorf <chbenkendorf(at)yahoo(dot)com> writes:
> I could not clear my doubt. Will the standard form, free disk space to the
> operational system or not?
It will release space to the OS if (a) there are one or more completely
empty pages at the end of the table and (b) it is able to get an
exclusive lock on the table (ie, there's not anyone else using the table
at the time).
regards, tom lane