On Mon, Feb 24, 2014 at 2:11 AM, Mohsen SM <mohsensoodkhah@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
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