Not if the column is storage type EXTERNAL. See a past discussion here: http://archives.postgresql.org/pgsql-general/2003-07/msg01447.php
what is the reasoning behind this syntax?
ALTER TABLE [ ONLY ] table [ * ] ALTER [ COLUMN ] column SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }
I find it nonintuitive and hard to remember. Perhaps something like this is better (I know, it's probably too late):
ALTER [ COLUMN ] column SET STORAGE { INLINE | EXTERNAL } ALTER [ COLUMN ] column SET COMPRESSION { YES | NO }
-- dave
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