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…
When a process spawn is aborted while the process spawning background is in the middle of spawning, the current session must wait until the pid of the new process is filled in. Once the pid is filled in, then the process spawn can be actually aborted.
A session waits for a checkpoint to complete. This could happen, for example, during a close database or a local checkpoint.
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…
Oracle does not really wait on this event; the foreground only yields the CPU. Thus, the chances of catching this event are very low. This is not an application induced deadlock, but an assumed deadlock by the cache layer. The cache layer cannot get a buffer in a certain mode within a certain amount of…
Processes enter “wait for broadcast mesg recovery queue transition” when cleaning up a publisher channel handle to a RELIABLE broadcast channel. The broadcasted message is in the recovery queue of another channel handle (for example, ch2). Process enters this wait, if the message is yet to be removed from the recovery queue of the ch2…
Processes enter “wait for broadcast mesg queue transition” when cleaning up a publisher channel handle to a RELIABLE broadcast channel. The publisher is responsible for moving the message to the free queue, but it cannot do so until the message is in the done queue. If the message is still not in the done queue,…
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.
Used to track the time (in centiseconds) that ARCn background processes spend blocked waiting for network write operations to complete.
Oracle Database Internal Mechanism 