protected void initLookup(){
  m_lookup=new HashMap();
  for (int i=0; i < m_names.length; ++i) {
    m_lookup.put(m_names[i],new Integer(i));
  }
}

protected void initLookup ( ) { m_lookup = new HashMap ( ) ; for ( int i = 0 ; i < m_names . length ; ++ i ) { m_lookup . put ( m_names [ i ] , new Integer ( i ) ) ; } }
lazily construct the lookup table for this schema . used to accelerate name - based lookups of schema information .
