?
Solved

Retrieve a dropped constraint

Posted on 2014-07-23
4
Medium Priority
?
240 Views
Last Modified: 2014-10-03
A constraint with a system generated name (SYS_CXXXXXXX) was accidentally dropped. Is there a way to add it back. The script for the constraint is not saved and I am not even sure on what table the constraint was applied so that I could do a comparison with the datamodel

Thanks,
0
Comment
Question by:gs79
  • 2
4 Comments
 
LVL 35

Accepted Solution

by:
johnsone earned 1000 total points
ID: 40216486
The only way I can think of that you might be able to retrieve it is with LogMiner.  You would have to have archive log mode turned on and know the timeframe when the drop occurred so that you could grab the correct archive(s).  It should give you the command to put back the constraint.

The documentation for LogMiner is here:

http://docs.oracle.com/cd/E11882_01/server.112/e22490/logminer.htm#SUTIL019
0
 
LVL 78

Assisted Solution

by:slightwv (䄆 Netminder)
slightwv (䄆 Netminder) earned 500 total points
ID: 40216539
You might also look at restoring a backup to a different server and see what it was.
0
 
LVL 29

Assisted Solution

by:MikeOM_DBA
MikeOM_DBA earned 500 total points
ID: 40219596
Constraints like "SYS_CXXXXXXX" are check constraints (99% of them "NOT NULL" constraints).
If you have a test or qa instance you could compare the schema's to production.
;)
0
 
LVL 35

Assisted Solution

by:johnsone
johnsone earned 1000 total points
ID: 40219752
They are not necessarily check constraints.  They can be any kind of unnamed constraint.  As long as you create it without a name, it will get a SYS_C prefix.

Take for example these 2 statements:

CREATE TABLE t 
  ( 
     x NUMBER PRIMARY KEY 
  ); 

CREATE TABLE u 
  ( 
     x NUMBER, 
     y NUMBER PRIMARY KEY, 
     FOREIGN KEY (x) REFERENCES t(x) 
  ); 

Open in new window


That will create 2 primary keys and one referential integrity constraint.  All of them will be prefixed with SYS_C.  At least they all were in the 11gR2 system I just ran those statements on.
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Working with Network Access Control Lists in Oracle 11g (part 2) Part 1: http://www.e-e.com/A_8429.html Previously, I introduced the basics of network ACL's including how to create, delete and modify entries to allow and deny access.  For many…
Background In several of the companies I have worked for, I noticed that corporate reporting is off loaded from the production database and done mainly on a clone database which needs to be kept up to date daily by various means, be it a logical…
This videos aims to give the viewer a basic demonstration of how a user can query current session information by using the SYS_CONTEXT function
This video explains what a user managed backup is and shows how to take one, providing a couple of simple example scripts.
Suggested Courses

621 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question