| From: | Gregory Stark <stark(at)enterprisedb(dot)com> |
|---|---|
| To: | "Pg Coder" <pgcoder(at)gmail(dot)com> |
| Cc: | <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: Char vs SmallInt |
| Date: | 2007-07-21 08:37:51 |
| Message-ID: | 87ps2m6tk0.fsf@oxford.xeocode.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-general |
"Pg Coder" <pgcoder(at)gmail(dot)com> writes:
> Which data type is smaller and will lead to better query performance -
> smallint or char?
smallint is 2 bytes, usually with 2-byte alignment.
If you declare a column as char it means CHAR(1) which in 8.2 is 5-8 bytes (5
bytes if it's an ascii character) and has 4-byte alignment. In 8.3 it's 2-5
bytes (2 bytes if it's an ascii character) and has 1-byte alignment.
If you declare a column as "char" with the quotes then it's a 1-byte integer
with 1-byte alignment. That'll be smaller than smallint.
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Nis Jørgensen | 2007-07-21 11:50:32 | Re: Foreign key constraint question |
| Previous Message | angga erwina | 2007-07-21 07:02:28 | Best interval timeout and check interval for Slony |