| From: | Ron Johnson <ron(dot)l(dot)johnson(at)cox(dot)net> |
|---|---|
| To: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: primary key index |
| Date: | 2007-05-14 07:45:47 |
| Message-ID: | 464813AB.4060703@cox.net |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-general |
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On 05/14/07 03:27, Sim Zacks wrote:
> Is a primary key an implicit index, or if I want to join on that field
> is it also worthwhile to make an explicit index?
On-line documentation is such a wonderful resource...
http://www.postgresql.org/docs/7.3/interactive/sql-createtable.html
PostgreSQL automatically creates an index for each unique
constraint and primary key constraint to enforce the uniqueness.
Thus, it is not necessary to create an explicit index for
primary key columns.
(Yes, I purposefully used the doc set of an ancient version.)
- --
Ron Johnson, Jr.
Jefferson LA USA
Give a man a fish, and he eats for a day.
Hit him with a fish, and he goes away for good!
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (GNU/Linux)
iD8DBQFGSBOrS9HxQb37XmcRAlhTAKDFekzal8p33SB5oW10NyTiQtkNQACeIXpP
Y8JuW+MjqIxWqZl86PsIxuw=
=TxAn
-----END PGP SIGNATURE-----
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Sim Zacks | 2007-05-14 08:27:18 | primary key index |
| Previous Message | Purusothaman A | 2007-05-14 07:45:10 | OID - file object, are damaged by PostgreSQL. |