Re: C constraints

From: fumi <fumi_at_tpts5.seed.net.tw>
Date: Mon, 26 Mar 2001 23:12:24 +0800
Message-ID: <99nmp5$qjp$1@news.seed.net.tw>

"Dudo" <dubravko.cunovic_at_ka.tel.hr> ¼¶¼g©ó¶l¥ó news:99gi3c$4gcc$1_at_as121.tel.hr...
> The CONSTRAINT_TYPE column in USER_CONSTRAINTS has only one value for all
> the tables:
> "C"
> No P or U or R ...
> What does it mean for performance?

They are used for data integrity, not for performance. Type of constraint definition:

C (check constraint on a table)
P (primary key)
U (unique key)
R (referential integrity)
V (with check option on a view)
O (with read only, on a view)

> If it isn't easy to explain, can you suggest any article on subject?

Take a look on Oracle Reference manual. Received on Mon Mar 26 2001 - 09:12:24 CST