Trace file not generated

There are some deletes that are going on for last 4 days and it appears that query is hung. The maximum records the query should delete is less than 200K. I tried to run a trace on that OS PID but I entered some wrong syntax which came up in that trace file. After that I deleted the trace file and corrected the syntax. Since the correction of syntax oracle is not generating the trace file. Please advise.

SQL> !ps -ef|grep 7569546
  oracle 6910136 6615220   0 09:15:15  pts/0  0:00 grep 7569546
  oracle 7569546       1  68   Apr 13      - 1357:00 ora_j000_cog3

SQL> oradebug setospid 7569546;
Oracle pid: 339, Unix process pid: 7569546, image: oracle@serverdb2