Re: Oracle 9i features?

From: Serge Rielau <srielau_at_ca.eye-be-em.com>
Date: Sat, 07 Feb 2004 11:36:32 -0500
Message-ID: <c0347c$jro$1@hanover.torolab.ibm.com>

Sybrand Bakker wrote:

> On 7 Feb 2004 00:39:22 -0800, pascaldamian_at_icqmail.com (Pascal Damian)
> wrote:
>

>>* computed field/column is not supported, use VIEW for that purpose;

>
>
> Has been supported all the time
>

Sybrand,
can you elaborate? When I researched generated columns I did not see that concept in the Oracle docs. Also I don't recall Oracle standards folks bringing it up when IBM brought the feature into SQL 4.

What Pascal seems to be refering to is:
SQL Server 2000: CREATE TABLE ... (c1 INT, c2 AS c1 + 5); (a virutal column) DB2 V7: ...c1 INT, c2 GENERATED ALWAYS AS (c1 + 5)..) (a materialized, functionally dependend, column)

AFAIK you would either use index on expression or a combination of before trigger and check constraint in Oracle, depending on the intended use.

Cheers
Serge

-- 
Serge Rielau
DB2 SQL Compiler Development
IBM Toronto Lab

Received on Sat Feb 07 2004 - 10:36:32 CST