Wait Event – cursor: mutex S

A session waits on this event when it is requesting a mutex in shared mode, when another session is currently holding a this mutex in exclusive mode on the same cursor object. Parameter Description P1 Hash value of cursor P2 Mutex value (top 2 bytes contain SID holding mutex in exclusive mode, and bottom two…

Wait Event – control file parallel write

This event occurs while the session is writing physical blocks to all control files. This happens when: The session starts a control file transaction (to ensure the control files are up to date in case the session crashes before committing the control file transaction) The session commits a transaction to a control file Changing a generic…

Wait Event – buffer read retry

This event occurs only if the instance is mounted in shared mode (Oracle Real Application Cluster). During the read of the buffer, the contents changed. This means that either: The version number, dba, or the incarnation and sequence number stored in the block no longer match The checksum on the block does not match the…

Wait Event – alter system set dispatcher

A session has issued a statement ALTER SYSTEM SET DISPATCHER = string and is waiting for the dispatchers to get started. Wait Time: The session will wait 1 / 100 of a second and verify if the new dispatchers have started, else the session will wait again