Today is OTN Appreciation day. In this reason Oracle bloggers share a blog post about himself favorite Oracle feature. This great idea coming from Tim Hall (@oraclebase). I also want share my favorite feature of Oracle Database. Here’s my contribution to the OTN Appreciation Day . How to Oracle working? - this question is interesting all of persons which is using Oracle database. Oracle trace files is very helpful for learn working mechanism of oracle processes. Each server and background process writes to a trace file. When a process detects an internal error, it writes information about the error to its trace file. DBMS_MONITOR is very good package for trace database, session, application, module... etc You can found your trace files in default folder : $ORACLE_BASE/diag/rdbms/SID/INSTANCE_NAME/trace Trace file is not more readable, you can use TKPROF for generate readable, text based file from trace files (*.trc) Read more about Application tracing https://docs.