I have never really played with log miner, but used it many times implicitly for streams. The need to get to grips with it arose when a developer created unrecoverable operations (i.e. something non-logging) in a QA system. I don't want them to run the same in production so I had to find out who did it. First of all I needed a test case on my 10.2.0.4 32bit Linux system, following these steps:

1. Build the dictionary

That's probably not always necessary, but I did create it anyway. I chose to put that into a file instead of the online redo logs since I couldn't/didn't want to enable supplemental logging on the database. With that said the streams initialisation-adding supplemental logging to all replicated tables makes a lot more sense! I also started to understand "dictionary_begin" and "dictionary_end" in v$archived_log more.

To build the dictionary to a file, you need to have utl_file_dir set correctly, which sounds a bit anachronistic nowadays where we have directories but I digress. In my case utl_file_dir was set to '/home/oracle/utl_file_dir'. The command I executed was:

begin
  DBMS_LOGMNR_D.BUILD(
    dictionary_filename => 'dictionary.ora',
    dictionary_location => '/tmp/', 
    options => DBMS_LOGMNR_D.STORE_IN_FLAT_FILE);
end;
/ 

2. Add log files

I knew from v$archived_log that my logfiles are for sequence 23 and 24 so I added them to the list of file to mine:

begin
  DBMS_LOGMNR.ADD_LOGFILE(
    LOGFILENAME => '/u01/oracle/ora10/arch/arch1_23_703580639.dbf', 
    OPTIONS => DBMS_LOGMNR.NEW);
  DBMS_LOGMNR.ADD_LOGFILE(
    LOGFILENAME => '/u01/oracle/ora10/arch/arch1_24_703580639.dbf', 
    OPTIONS => DBMS_LOGMNR.NEW);
end;
/ 

3. Start log miner

Now for the interesting part of this!

begin
 dbms_logmnr.start_logmnr( 
    dictfilename => '/home/oracle/utl_file_dir/dictionary.ora');
end;
/ 

4. Analysing the results

Now query v$logmnr_contents at your heart's delight!

5. End your log miner session

The final step is to end the session.

begin
 dbms_logmnr.end_logmnr;
end;
/