What does 'No', 'Yes' and 'Global' mean in the 'Block' column in Session Browser and how to use this information to determine which sessions are being locked.
The BLOCK column in session browser is derived from the V$LOCK (or GV$LOCK if 'Use RAC view' is checked) view column 'BLOCK' which can have the value 0, 1 or 2.
Session browser display
Value '0' --> 'No' This is NOT a blocking session
Value '1' --> 'Yes' This IS a blocking session
Value '2' --> 'Global' This is a DML lock by Oracle at the database level
Click on a session which has the Block value Yes' and then select the 'Blocked locks' tab, you will see which sessions/transactions are being blocked
Click on a session which has the Block value 'No' and then select the 'Blocking locks' tab, you will see which session is blocking.
If you require more information relating to the significance of the values 0,1& 2 from the V$LOCK/GV$LOCK view, please refer to Oracle documentation.
