Detailed Oracle commit usage

Oracle commit detailed usage commit working process before commit is submitted Oracle generates a revocation record in the SGA undo segment buffer, the undo record contains the old value www.2cto.com for updating and deleting table rows. Oracle generates a redo log record in the SGA redo log buffer. The transaction in the redo log record is marked as the committed transaction when the buffer commit in the Oracle modified SGA database is committed. the unique scn log writing program will redo the transaction log information and the transaction scn, release the Oracle lock from the redo log files written from the redo log buffer to the disk, mark the transaction as completing the commit_wait initialization parameter commit_wait = {nowait | wait | force_wait} by default, Oracle uses the commit method as the role of wait: controls the write mode of redo logs. Remarks: nowait application scenarios (a, there are a large number of transaction redo logs, and the information needs to be written into the redo log; B, tolerate partial data loss) C. Wait until LGWR is written, which cannot be tolerated by the application ). Force_wait: oracle will be applied by default to submit commit_logging initialization parameter commit_logging = {immediat | batch} immediat: LGWR to write redo information to the redo log file immediately batch: The redo information will be buffer, that is, the redo logs are not immediately written to the redo log file. The usage of commit write wait; commit write nowait commit write batch; commit write immediate; wait and nowait control when redo information is written to redo logsimmediat and batch control how redo information is written to redo logs. Remarks: pl/SQL default batch nowait