On 2/15/24 08:16, Greg Sabino Mullane wrote:
So as I also tested the same as you posted, there has been no change
in "ctid" , when I altered the column data type from 'int' to
'bigint' in the table, so that means full table rewriting
won't happen in such a scenario.
No it was definitely rewritten - do not depend on the ctid to verify
that. Take our word for it, or
use*pg_relation_filenode('int_test');* before and after, as well as
*pg_relation_size('int_test')*;
That is a mixed bag:
test=# select pg_relation_filenode('int_test');
pg_relation_filenode
----------------------
69999
(1 row)
test=# select pg_relation_size('int_test');
pg_relation_size
------------------
368640
(1 row)
test=# alter table int_test alter column int_fld set data type bigint;
ALTER TABLE
test=# select pg_relation_filenode('int_test');
pg_relation_filenode
----------------------
70002
(1 row)
test=# select pg_relation_size('int_test');
pg_relation_size
------------------
368640
Cheers,
Greg
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
