On Mon, Feb 24, 2014 at 2:11 AM, Mohsen SM <mohsensoodk...@gmail.com> wrote: > when did use varchar_transform function? > src/backend/uitls/adt/varchar.c.
The main point of that machinery is that if you do something like ALTER TABLE zot ALTER COLUMN thunk SET DATA TYPE varchar(30) on a column that is currently varchar(20), it won't feel obliged to rewrite the table. That function lets it figure out that anything that's a valid varchar(20) value is also a valid varchar(30) value. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers