Wait Event – log file parallel write

Writing redo records to the redo log files from the log buffer. Wait Time: Time it takes for the I/Os to complete. Even though redo records are written in parallel, the parallel write is not complete until the last I/O is on disk.   Parameter Description files Number of files to be written blocks Number of…

Wait Event – cursor: pin X

A session waits on this event when it is requesting an exclusive mutex pin for a cursor object and it must wait because the resource is busy. The mutex pin for a cursor object can be busy either because a session is already holding it exclusive, or there are one or more sessions which are holding…

Wait Event – broadcast mesg recovery queue transition

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…

Wait Event – broadcast mesg queue transition

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,…

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

latch: cache buffers chains – Oracle wait event

The Buffer cache is implemented as a chain of blocks linked together under a hash value known as cache buffer chains (CBC). When a buffer is requested the hash value of the chain where the buffer is, will be calculated and then that chain is scanned by walking the chain until the buffer is found.…