My porblem is that I'm doing migration from HSQLDB to Oracle11g. I got to do it so I'm writing what I've done hoping to help someone else in my situation.
1) Do regular Import/Export using Alfresco tools and bootstrap as described in the wiki. Now the destination Alfresco is aligned, except from workflow instances.
2) Disable constraints from destination database
3) Install SquirreSql with the plugins: CopyDb, and the databases that apply
4) Copy the jars of the dirvers if necessary (the hsqldb jar is in the alfresco lib folder..)
5) Create the 2 aliases to the databases (the connection definitions)
6) Use copy db (select any JBPM* table, right mouse button, copy table) from the hsqldb session, select the destination schema and right button, paste tables.
7) Reenable contraints in dest db
😎 Done! Alfresco doesn't even need to be restarted!