--- old/mensa.cpp	2012-07-05 14:32:13.000000000 +0530
+++ new/mensa.cpp	2012-07-05 14:32:05.000000000 +0530
@@ -274,6 +274,7 @@
 	    ibis::column* col = (*it)->getColumn(colname);
 	    if (col != 0)
 		col->indexSpec(opt);
+	    (*it)->updateMetaData();  // Persit the index spec in the metadata file.
 	}
     }
 } // ibis::mensa::indexSpec