code: public List<IndexInfo> getIndexInfo(String tblName, String fldName, Transaction tx) {
  		// Check the cache
  		if (!loadedTables.contains(tblName)) {
  			readFromFile(tblName, tx);
  		}
  		
  		// Fetch from the cache
  		Map<String, List<IndexInfo>> iiMap = iiMapByTblAndFlds.get(tblName);
  		if (iiMap == null)
  			return Collections.emptyList(); // avoid object creation
  		List<IndexInfo> iiList = iiMap.get(fldName);
  		if (iiList == null)
  			return Collections.emptyList(); // avoid object creation
  		
  		// Defense copy
  		return new LinkedList<IndexInfo>(iiList);
  	}
docs: Returns a map containing the index info for all indexes on the specified
  table.
  
  @param tblName
  the name of the table
  @param fldName
  the name of the search field
  @param tx
  the context of executing transaction
  @return a map of IndexInfo objects, keyed by their field names