public void setChildDatabaseName(String databaseName) {
    this.childDatabaseName = databaseName;
  }
ForeignKeyInfo is a metadata structure containing the foreign keys associated with a table.
The fields include the child database name, the child table name, mapping of the constraint
name to the foreign key columns associated with the key. The foreign key column structure 
contains the parent database name, parent table name, associated parent column name,
associated child column name and the position of the foreign key column in the key.
The position is one-based index.
ql/src/java/org/apache/hadoop/hive/ql/metadata/ForeignKeyInfo.java