OWNER_CONNECTION_ID in M_SQL_PLAN_CACHE

Hi there,

For some monitoring purpose, I need the use of M_SQL_PLAN_CACHE system view, but I see most of the values in the OWNER_CONNECTION_ID are -1, I just want to know the reason why it is -1 and what -1 indicates!

Another thing is that in M_CONNECTIONS, I see some (not all) of the CONNECTION_ID are negative (like -200,XXX), again, may I know why is that negative?

Thanks.