Increasing the size of character varying type in postgres without data loss

Question

I need to increase the size of a character varying(60) field in a postgres database table without data loss.

I have this command

alter table client_deta         


        

Answer 1

Changing the Column Size in Postgresql 9.1 version

During the Column chainging the varchar size to higher values, table re write is required during this lock will be held on table and user table not able access till table re-write is done.

Table Name :- userdata Column Name:- acc_no

ALTER TABLE userdata ALTER COLUMN acc_no TYPE varchar(250);