text vs. varchar
Is there any difference between "text" and "varchar" data types? (Not varchar(n), just varchar.) I can't see a different from the manual page, but I'm wondering about index usage or something similarly subtle.
On Wed, 2010-07-21 at 08:58 -0700, Ben Chobot wrote:
Is there any difference between "text" and "varchar" data types? (Not varchar(n), just varchar.) I can't see a different from the manual page, but I'm wondering about index usage or something similarly subtle.
They are the same thing. So is varchar(n) it just has a length
constraint.
JD
--
PostgreSQL.org Major Contributor
Command Prompt, Inc: http://www.commandprompt.com/ - 509.416.6579
Consulting, Training, Support, Custom Development, Engineering
varchar allows you to define an explicit length of the field, text does not.
varchar with a length specified (varchar(n)) is sql92 compliant while
varchar() and text are pgsql extensions.
On 2010-07-21 08:58:54AM -0700, Ben Chobot wrote:
Is there any difference between "text" and "varchar" data types? (Not varchar(n), just varchar.) I can't see a different from the manual page, but I'm wondering about index usage or something similarly subtle.
--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
--
===========================================================
Peter C. Lai | Bard College at Simon's Rock
Systems Administrator | 84 Alford Rd.
Information Technology Svcs. | Gt. Barrington, MA 01230 USA
peter AT simons-rock.edu | (413) 528-7428
===========================================================
Import Notes
Reply to msg id not found: 19656_1279728019_4C471992_19656_40_1_053345DC-DBFB-44E9-9E37-CAABC13A539C@silentmedia.comReference msg id not found: 19656_1279728019_4C471992_19656_40_1_053345DC-DBFB-44E9-9E37-CAABC13A539C@silentmedia.com | Resolved by subject fallback
On 21 July 2010 16:58, Ben Chobot <bench@silentmedia.com> wrote:
Is there any difference between "text" and "varchar" data types? (Not varchar(n), just varchar.) I can't see a different from the manual page, but I'm wondering about index usage or something similarly subtle.
--
Here's what Tom Lane had to say on the matter when I asked previously:
"There is some potential overhead from using varchar instead of text
because of the extra dummy cast nodes that are likely to be present in
your query expressions (since all the native functions are declared to
take/return text, not varchar). In most cases I'd think you'd be
hard-put to measure any difference though."
Thom
On Jul 21, 2010, at 9:05 AM, Thom Brown wrote:
On 21 July 2010 16:58, Ben Chobot <bench@silentmedia.com> wrote:
Is there any difference between "text" and "varchar" data types? (Not varchar(n), just varchar.) I can't see a different from the manual page, but I'm wondering about index usage or something similarly subtle.
--Here's what Tom Lane had to say on the matter when I asked previously:
"There is some potential overhead from using varchar instead of text
because of the extra dummy cast nodes that are likely to be present in
your query expressions (since all the native functions are declared to
take/return text, not varchar). In most cases I'd think you'd be
hard-put to measure any difference though."
Thanks, this is precisely what I was looking for.