What is the purpose of 'uniqueConstraintName' in the <constraint> tag?

I’m wondering what the uniqueConstraintName element of the tag is in the changelog XML file actually does?
When I try to give my unique columns a name such as:

and then install (update) the changelog into an HSQL in-memory database and diff it against an empty DB2 database, it doesn't use the constraint name I gave it.  Instead it gives me this name in the report output:
    Missing Indexes:


I also don’t understand why it’s being reported under Missing Indexes instead of Missing Unique Constraints?  I can’t see any way to get Liquibase diff to report show anything under Missing/Unexpected Unique Constraints.

I probably asked you before, but what version of liquibase are you running? 

Not having the code in front of me right now, it could be that hsql does not support named unique indexes.  As to why it is being reported under missing indexes, the jdbc metadata coming back makes it hard to differentiate between indexes and unique constraints at times.  There is logic in there to try to figure it out, but it gets confused at times.  I plan to put some major work into the diff tool for the 2.1 release.  I do consider the diff tool to be a guide, though, and not something that should be relied on.


OK, thanks.
According to the pom.xml file, we branched from 2.0-rc2-SNAPSHOT.
We’re using HSQL 2.0.0-rc8 & DB2 8.2.