Comment 6 for bug 931602

MyISAM does not support FK constraints. If mysql is set to use MyISAM as default, any FK created prior to 022_set_engine_mysql_innodb.py ends up being missing later on. Converting tables to InnoDB in 022 does not create the FKs, and sqlalchemy does nothing to ensure they are created. We should add migration somewhere that ensures missing FKs exist and ensure schemas are consistent across storage engines so that errors like this turn up in gating, as this seems to happen often. I'll file a bug and submit something for that.