public void compileSortCriteria(String sortCriterion) {

    CompiledValue obj = pop();
    boolean criterion = sortCriterion.equals("desc");
    CompiledSortCriterion csc = new CompiledSortCriterion(criterion, obj);
    push(csc);

  }
compiles sort criteria present in order by clause and push into the stack
geode-core/src/main/java/org/apache/geode/cache/query/internal/QCompiler.java