Mysteriously Inconsistent Behaviour of ORACLE 7.3.3

From: NNOOR <Nnoor_at_cris.com>
Date: 1997/06/06
Message-ID: <5n8uab$4l3@chronicle.concentric.net>#1/1

I experienced following in Oracale 7.3.3 WGS NT which I don't have any explanation for.

I have a view defined on ATable as following...

Select...[snip]
Where....
..... AField = 1

NOTE: AField used to be of type Number when this view was written. Field type was changed to be VARCHAR2(2) some time ago. But this view kep working fine. Yesterday, all of a sudden, I started to get an Oracle error message "Invalid Number" during a process which is run hundreds of times a day and uses the above view every single time. Once this error message showed up, it was persistent in appearing every single time. After being totally clueless for some time, I tried the following change in the query:
.... AField = '1' (i.e. enclose 1 in quotes)

It made the problem go away. I am toally baffled. Why would Oracle suddenly decide to cough up on an issue which it simply ignored for quite a long while?

(No, the data in the ATable had not changed in days).

Any clues?

Regards,
Nasir (nnoor_at_cris.com) Received on Fri Jun 06 1997 - 00:00:00 CDT