Oracle 11.2.0.4 -- sql_id not found in v$sql or v$session

I was looking in v$session_longops and found an operation currently being run and its corresponding SQL_ID

SELECT sql_id, sid, to_char(start_time,'hh24:mi:ss') stime, time_remaining,message,( sofar/totalwork)*100 percent FROM v$session_longopsWHERE sofar/totalwork < 1/SQL_ID  SID STIME   TIME_REMAINING  MESSAGE PERCENT381hwy1dbtntp   104 09:36:57    157 Index Fast Full Scan:  SOME_USER.SOME_TABLE: 12715 out of 36702 Blocks done 34.643888616424173069587488420249577679690htuhsqj193gf   184 09:15:21    4488    Table Scan:  SOME_USER.SOME_TABLE: 7028 out of 13568 Blocks done    51.79834905660377358490566037735849056604

When I look for the user session running this based on the SQL_ID I didn't find any session running the first one. (381hwy1dbtntp)

select distinct sql_id from v$session;SQL_IDfwxv8a99vkg9r1cwb8j02491w0gypnfv5nzurb00htuhsqj193gf2b064ybzkwf1y

I also looked in v$sql and could not find any records with this sql_id. Could someone help out with some pointers explaining the reasoning behind this?

Thanks