@Override protected int getMapNameLength(String[] keys) {
    return SCHEMAS.length;
  }
The number of fragments that will be used to determine the map name.
@param keys key fragments
@return a number equal (or inferior) to <code>keys.length - 1</code> since a property name is at least 1 fragment
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/properties/HMSPropertyManager.java