The following bug has been logged online: Bug reference: 4689 Logged by: Email address: xuan--2009.03--submitbug--support--postgresql....@baldauf.org PostgreSQL version: 8.3.5 Operating system: Linux 2.6.18-6-amd64 Description: Expanding the length of a VARCHAR column should not induce a table rewrite Details:
Suppose there is a table "sometable" with a column "somecolumn" of type "VARCHAR(5)". This table as many rows. When executing "ALTER TABLE sometable ALTER COLUMN somecolumn TYPE VARCHAR(7)", the whole table is re-written, and this rewrite takes many hours. During these hours, all writers on this table stall, making the database effectively unavailable. However, in almost all cases, there is no need for such relaxing of limits to require a table rewrite. So the expected run time needed for this statement is about one second, the actual run time needed for this statement is many hours. -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
