Scope of a constraint name? (ORA-02264: name already used by an existing constraint)

Posted on 2004-10-19
Last Modified: 2012-08-13
Hello experts,
I would like to know the scope of constraint name.  I've read the manual ( but couldnt find the needed info.

In particular, when I run the following sql:
CREATE TABLE myTable02 ( ItemID1 RAW(4) NOT NULL, #more fields here# , CONSTRAINT ItemID_p_k PRIMARY KEY(ItemID1) );
an error is returned: ORA-02264: name already used by an existing constraint

Note that before running the above statement, another sql has been run successfully (only the table name is different):
CREATE TABLE myTable01 ( ItemID1 RAW(4) NOT NULL, #more fields here# , CONSTRAINT ItemID_p_k PRIMARY KEY(ItemID1) );

So the question is: is the scope of the constraint name (ItemID_p_k) bound by the schema or the table? If the scope of constraint is within a table, then why do I have the error?

Question by:dttai
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3

Accepted Solution

morphman earned 500 total points
ID: 12345378
It is bound by the schema.

You must have different constraint names for every constraint in a schema. It is common practice to include the table name in the constraint name.

Author Comment

ID: 12345423
Thanks morphman,
Just a follow-up question: is the length limit on identifier applied to all including table name, index name, constraint name, etc..? Table name limited to 32 chars seems a little too short for me.

Expert Comment

ID: 12345439
yes, unfortunateley this is true. However it is even worse for you as the limit is 30 characters, not 32.
Instantly Create Instructional Tutorials

Contextual Guidance at the moment of need helps your employees adopt to new software or processes instantly. Boost knowledge retention and employee engagement step-by-step with one easy solution.


Author Comment

ID: 12351618
Thanks morphman,
You will get all the points I previously posted (250).
Since I've a number of questions related to  scope, I will just continue to post it here. Those who answer these questions will get the points I just increase.
1) when i check all_indexes, they have at least two fields (index_name, table_name). However, if I create indexes on two tables with the same index name, Oracle still complains. I guess index name is also bound by schema. Anyhow, I found this scope is rather inconvenient. Why don't they just go ahead and use the pair (index_name, table_name) to identify an index. That way two tables can be allowed to have the same name for their indexes.

... Please check back for several more questions.
Thanks all,

Author Comment

ID: 12351659
2) Where can I find the length limit on name for all sorts of identities in Oracle.
I know:
table name: 32 chars
constraint name: 30 chars
index name: 32 or 30?
view name: ??
user name: ??
Better yet, if you happen to know which Oracle doc has all of these info, please share with me.


Assisted Solution

morphman earned 500 total points
ID: 12352215

Table names are definateley only 30 characters in length.

In fact all oracle identifiers are limited to 30 characters in length.

See here:-

table a-1


Featured Post

Veeam gives away 10 full conference passes

Veeam is a VMworld 2017 US & Europe Platinum Sponsor. Enter the raffle to get the full conference pass. Pass includes the admission to all general and breakout sessions, VMware Hands-On Labs, Solutions Exchange, exclusive giveaways and the great VMworld Customer Appreciation Part

Question has a verified solution.

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

How to Unravel a Tricky Query Introduction If you browse through the Oracle zones or any of the other database-related zones you'll come across some complicated solutions and sometimes you'll just have to wonder how anyone came up with them.  …
When it comes to protecting Oracle Database servers and systems, there are a ton of myths out there. Here are the most common.
This video shows syntax for various backup options while discussing how the different basic backup types work.  It explains how to take full backups, incremental level 0 backups, incremental level 1 backups in both differential and cumulative mode a…
Via a live example, show how to restore a database from backup after a simulated disk failure using RMAN.
Suggested Courses

632 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