Sortable Implementation

The logic that defines the sortable feature is wired into the core engine. The sortable feature is activated by setting the sortable flag for a CEId field.

Rank Field

For each sortable field the system creates a rank field in the same table as the sortable field. This field stores a rank value that represents the order of the rows with respect to the sortable field.

If the sortable field is in the module table, the rank field is also placed in the module table. The rank field is then named after the sortable field extended by the suffix _rank. If the sortable field is placed in an external table the rank field is placed in the same external table and is simply named rank.

Placing the rank and the sortable field in the same table allows to create a database index over both fields. This index is considered necessary because order by queries referring to both fields are expected be performed frequently.