CREATE TABLE table_17115950_2 (date_of_vacancy VARCHAR2, replaced_by VARCHAR2)

What was the date of vacancy when Viorel Moldovan replaced a manager?
SELECT date_of_vacancy FROM table_17115950_2 WHERE replaced_by = "Viorel Moldovan"
SELECT "date_of_vacancy" FROM "table_17115950_2" WHERE "Viorel Moldovan" = "replaced_by"