Closes #12626 (grafted from 2f04f787260ea6bd52ecf4b3ac414d343c78dc70) --HG-- branch : 6.0
This avoids uniqueness constraint error in case of concurrent creation. Closes #10747 (grafted from c4674b8f6fbda574212a4b1768afd86f4651f7c7) --HG-- branch : 6.0
--HG-- branch : 6.0