String indexName = unescapeIdentifier(ast.getChild(0).getText());
String typeName = unescapeSQLString(ast.getChild(1).getText());
String tableName = unescapeIdentifier(ast.getChild(2).getText());
List<String> indexedCols = getColumnNames((ASTNode) ast.getChild(3));
IndexType indexType = HiveIndex.getIndexType(typeName);
if (indexType != null) {
typeName = indexType.getHandlerClsName();
} else {
try {
Class.forName(typeName);
} catch (Exception e) {
throw new SemanticException("class name provided for index handler not found.", e);