Returns the dbkey of the last record read in a currently readied
       relational domain or table.

1  –  Input

       A string expression providing the name of the domain or table.

2  –  Output

       The record dbkey as a byte string.

3  –  Example

       In the following example the FN$FORMAT_DBKEY function returns the
       dbkey of the last record read from CITY_CODE_TABLE in its string
       format.

       DTR> PRINT FN$FORMAT_DBKEY(FN$LASTREC_DBKEY("CITY_CODE_TABLE"))
                  FN$FORMAT
                        DBKEY

       11:149:26
       DTR>