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Notes:
There are a few undocumented flashback database-related parameters that could be investigated for additional control and tuning options. See the script flashback_parameters_undocumented.sql for the following code:
SYS@orcl> SELECT x$ksppi.ksppinm, x$ksppi.ksppdesc, x$ksppcv.ksppstvl
2 FROM x$ksppi, x$ksppcv
3 WHERE x$ksppi.indx = x$ksppcv.indx
4 and x$ksppi.ksppinm like '/_%flashback%' escape '/'
5 order by 1;
KSPPINM KSPPDESC KSPPSTVL
----------------------------------- ---------------------------------------- ----------
_flashback_allow_noarchivelog Allow enabling flashback on noarchivelog FALSE
database
_flashback_barrier_interval Flashback barrier interval in seconds 1800
_flashback_copy_latches Number of flashback copy latches 10
_flashback_fuzzy_barrier Use flashback fuzzy barrier TRUE
_flashback_generation_buffer_size flashback generation buffer size 4194304
_flashback_hint_barrier_percent Flashback hint barrier percent 20
_flashback_log_io_error_behavior Specify Flashback log I/O error behavior 0
_flashback_log_min_size Minimum flashback log size 100
_flashback_log_size Flashback log size 1000
_flashback_logfile_enqueue_timeout flashback logfile enqueue timeout for 600
opens
_flashback_max_log_size Maximum flashback log size in bytes (OS 0
limit)
_flashback_max_n_log_per_thread Maximum number of flashback logs per 2048
flashback thread
_flashback_n_log_per_thread Desired number of flashback logs per 128
flashback thread
_flashback_standby_barrier_interval Flashback standby barrier interval in 1800
seconds
_flashback_verbose_info Print verbose information about FALSE
flashback database
_flashback_write_size_qm Desired flashback write size in quarter 4
MB
_percent_flashback_buf_partial_full Percent of flashback buffer filled to be 50
considered partial full
_validate_flashback_database Scan database to validate result of FALSE
flashback database
_verify_flashback_redo Verify that the redo logs needed for TRUE
flashback are available
19 rows selected.