Search notes:

Oracle: Init parameter SQL_TRACE

alter session set sql_trace=true;

select value from v$diag_info where name = 'Default Trace File';

… execute some SQL statements…

alter session set sql_trace=false;

See also

dbms_monitor.session_trace_enable and session_trace_disable.
Trace files
Prerequisites for filling V$SQL_PLAN_STATISTICS and V$SQL_PLAN_STATISTICS_ALL
The parameter tracefile_identifier 
alter session set events '10046 level …';
init parameters

Index

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 8 attempt to write a readonly database in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php:78 Stack trace: #0 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(78): PDOStatement->execute(Array) #1 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(30): insert_webrequest_('/notes/developm...', 1758198689, '216.73.216.150', 'Mozilla/5.0 App...', NULL) #2 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/development/databases/Oracle/adminstration/init-parameters/sql_trace/index(56): insert_webrequest() #3 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 78