Search notes:

ORA-01031: insufficient privileges

The error ORA-01031: insufficient privileges is typically thrown if a user lacks a privilege to execute an SQL statement (when already connected to the database, in contrast to ORA-01031: insufficient privileges which is raised if a user cannot be authenticated to connect to the database).
Necessary privileges can be given to a user (or a role) with the grant statement.

Starting an instance

If this error is thrown when an instance is started up, it might indicate that the user trying to start the instance does not belong to the ora_dba group on Windows or dba group on Unix.
On Windows, a user can be added to the Window group with 
net localgroup ora_dba rene /add

See also

ORA-01039: insufficient privileges on underlying objects of the view
SQL parsing
MOS Note 730067.1 points out that ORA-01031 may be thrown if the definition of SQLNET.AUTHENTICATION_SERVICES in tnsnames.ora has leading blank spaces.
Other Oracle error messages

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...', 1740469411, '18.118.55.201', 'Mozilla/5.0 App...', NULL) #2 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/development/databases/Oracle/errors/ORA-01031_insufficient-privileges/index(57): insert_webrequest() #3 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 78