In some scenario or as per customer requirement, you need to delete all the Q from SMQ2. Manual deletion of Q is pain & it takes lot of time.
You can follow below method to truncate the table in safe method.
Table Name – TRFCQIN (SMQ2)
For Oracle
SQL>select count(*) from sapsr3.TRFCQIN;
COUNT(*)
———-
2517434
Cross verify the count from SMQ2 with Oracle Result.
SQL>truncate table SAPSR3.TRFCQIN;
From SAP
SE14 – TRFCQIN
Delete Data – Activate & Adjust Database.
Now your SMQ2 is empty.