WL#8149  B-tree Index Support on non-materialized virtual columns
    WL#8114  Don't store virtual generated columns in database
    WL#8227  Support SEs to create index on virtual generated columns
    WL#8481  Callback for computation of virtual column index values
    from InnoDB purge threads
    All 4 worklogs are to support virtual column and virtual index on such
    columns