Bug #45736 Can't create an FK without an index on the columns
Submitted: 25 Jun 2009 3:02 Modified: 13 May 2010 16:03
Reporter: Andrew Dalgleish Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: InnoDB storage engine Severity:S4 (Feature request)
Version:5.0 OS:Any
Assigned to: CPU Architecture:Any
Triage: Needs Triage: D5 (Feature request)

[25 Jun 2009 3:02] Andrew Dalgleish
Description:
A customer reports they would like to be able to drop the index from an existing foreign key relationship, or create an FK without an index.

They have read the documentation on FK constraints, and understand the potential performance penalties.

How to repeat:
NA - feature request
[25 Jun 2009 3:45] Valeriy Kravchuk
Thank you for the feature request. Although there are few cases (I can't think of any really good example at the moment) when FK without index is needed, Oracle RDBMS, for example, allows to declare FK without creating index. So, there is some reason to have the same feature, at least, in Oracle compatibility sql_mode.