LOG_CHECKPOINT_INTERVAL [message #56543] |
Mon, 07 April 2003 15:17 |
reshma
Messages: 10 Registered: January 2003
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Junior Member |
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Hi,
an anybody Describe the significance of the parameter log_checkpoint_internal in instance recovery?
Thanks
Reshma
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Re: LOG_CHECKPOINT_INTERVAL [message #56557 is a reply to message #56543] |
Tue, 08 April 2003 11:27 |
Anand
Messages: 161 Registered: August 1999
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Senior Member |
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LOG_CHECKPOINT_INTERVAL specifies the frequency of checkpoints in terms of the number of redo log file blocks that can exist between an incremental checkpoint and the last block written to the redo log. This number refers to physical operating system blocks, not database blocks.
Regardless of this value, a checkpoint always occurs when switching from one online redo log file to another. Therefore, if the value exceeds the actual redo log file size, checkpoints occur only when switching logs. Checkpoint frequency is one of the factors that influence the time required for the database to recover from an unexpected failure.
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Notes:
Specifying a value of 0 (zero) for LOG_CHECKPOINT_INTERVAL has the same effect as setting the parameter to infinity and causes the parameter to be ignored. Only nonzero values of this parameter are considered meaningful.
Recovery I/O can also be limited by setting the FAST_START_IO_TARGET or LOG_CHECKPOINT_TIMEOUT parameter or by the size specified for the smallest redo log. For information on which mechanism is controlling checkpointing behavior, query the V$INSTANCE_RECOVERY view.
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