A session waits for this event when it is requesting a shared mutex pin and another session is holding an exclusive mutex pin on the same cursor object. Wait Time: Microseconds Parameter Description P1 Hash value of cursor P2 Mutex value (top 2 bytes contains SID holding mutex in exclusive mode, and bottom two bytes…
A session waits on this event when it wants to update a shared mutex pin and another session is currently in the process of updating a shared mutex pin for the same cursor object. This wait event should rarely be seen because a shared mutex pin update is very fast. Wait Time: Microseconds Parameter Description P1…
The session requests the mutex for a cursor object in exclusive mode, and it must wait because the resource is busy. The mutex is busy because either the mutex is being held in exclusive mode by another session or the mutex is being held shared by one or more sessions. The existing mutex holder(s) must release…
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…
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…
The session waits on the buffer hash chain latch. Primarily used in the dump routines. The virtual address in the SGA where this latch is located. Use the following statement to find the name of this latch: select * from v$latch a, v$latchname b where addr = latch addr and a.latch# = b.latch#; chain# The…
A session is waiting on another process to allocate a system change number (SCN). If the foreground timed out waiting on a process to get the SCN, the foreground will get the SCN.
Cause: The value of the DB_FILES initialization parameter was exceeded. Action: Increase the value of the DB_FILES parameter and warm start.
Cause: DB_BLOCK_SIZE initialization parameter is wrong for the database being mounted. It does not match the value used to create the database. Action: Fix the value of the DB_BLOCK_SIZE parameter or mount a database that matches the value.
Cause: The number of temporary tables equals or exceeds the number of temporary table locks. Temporary tables are often created by large sorts. Action: Increase the value of the TEMPORARY_TABLE_LOCKS initialization parameter and warm start.
Oracle Database Internal Mechanism 