Explanation:
SMON is Oracle background process, which handles instance recovery after database startup if necessary, and periodically coalesces smaller chunks of free space in table spaces into larger chunks. The main function of SMON in instance recovery is to roll forward transactions applying changes in the redo log files. Also a function of SMON in Oracle8 is to deallocate space in temporary segments no longer in use.
Incorrect Answers:
1: SMON does not write data anywhere itself, ARCH process writes data to the archive log files.
2: SMON does not write data anywhere itself, LGWR process writes data changes into redo log files.
3: PMON process frees resources held by user processes, not SMON.
4: CKPT process synchronizes data file header and control file.
6: DBWR background process writes dirty buffers from the buffer cache to the datafiles.
Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 565
Chapter 12: Overview of Backup and Recovery

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