code: public boolean isIndexed(String id) {
  		DatabaseEntry key = new DatabaseEntry();
  		StringBinding.stringToEntry(id, key);
  		DatabaseEntry data = new DatabaseEntry();
  		if ((idToIidDB.get(null, key, data, null) == OperationStatus.SUCCESS)) {
  			return true;
  		} else {
  			return false;
  		}
  	}
docs: <b>{@link #getInternalId(String)} can always be called instead of this method at the same cost!</b>
  <br>
  Checks if the vector with the given id is already indexed. This method is useful to avoid re-indexing
  the same vector. Its convention is that if the given name is already in idToIidBDB, then the vector is
  indexed in all other structures e.g. iidToIdBDB. The rest of the checks are avoided for efficiency.
  Accesses the BDB store!
  
  @param id
  The id the vector
  @return true if the vector is indexed, false otherwise