On Wed, Dec 9, 2015 at 5:17 PM, Kevin Grittner <kgrittn@xxxxxxxxx> wrote: > On Wed, Dec 9, 2015 at 5:13 PM, Edson Richter <edsonrichter@xxxxxxxxxxx> wrote: > >> I do have several tables that uses varchar(2000) as store for remarks. >> Lately, one customer need to store more than 2000 characteres, and I'm >> considering changing from varchar(2000) to text. >> >> What is the overhead? > > None -- they are stored in exactly the same format; the only > difference is whether the length is limited. I probably should have mentioned that an ALTER TABLE to change the column type from varchar(2000) to text does not rewrite the data (since it is in the same format) -- it just changes the catalogs to reflect the lack of a limit on length. Changing the other way would require a pass to check that all existing data passes the length check. >> Is there any place where I can learn about storage impacto for each data >> type? > > http://www.postgresql.org/docs/current/interactive/datatype-character.html While it's fairly technical, you might also be interested in this: http://www.postgresql.org/docs/current/interactive/storage-toast.html -- Kevin Grittner EDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
