Oracle 参数 LOG_CHECKPOINT_TIMEOUT 官方解释，作用，如何配置最优化建议
本站中文解释
LOG_CHECKPOINT_TIMEOUT是是在Oracle数据库中定义了一个检查点超时时间。该属性定义了数据库引擎在检查点期间应等待最大限度的秒数，在该时间间隔内，日志缓冲区必须完成清理，以便将改变写入库结构和数据文件中。
正确设置LOG_CHECKPOINT_TIMEOUT的方法：
1、首先要分析数据库的环境，根据这个环境分析检查点的负载，大致确定检查点的等待时间；
2、如果你发现Oracle在检查点期间正在等待太多，那么可以考虑增加时间；
3、如果发现Oracle在检查点期间正在等待太多，那么可以考虑降低时间以提高性能；
4、在所有的调整之后，需要根据实际业务的情况和使用的情况，随时进行调整，保证性能最大化；
5、如果在调整之后发现数据库性能有所提高，但还有其他性能问题，那么可以尝试其他的参数调整，以解决性能问题。
官方英文解释
LOG_CHECKPOINT_TIMEOUT specifies (in seconds) the amount of time that has passed since the incremental checkpoint at the position where the last write to the redo log (sometimes called the tail of the log) occurred. This parameter also signifies that no buffer will remain dirty (in the cache) for more than integer seconds.
| Property | Description |
|---|---|
|
Parameter type |
Integer |
|
Default value |
|
|
Modifiable |
|
|
Modifiable in a PDB |
No |
|
Range of values |
|
|
Basic |
No |
|
Oracle RAC |
Multiple instances can have different values. |
Specifying a value of 0 for the timeout disables time-based checkpoints. Hence, setting the value to 0 is not recommended unless FAST_START_MTTR_TARGET is set.
Note:
-
A checkpoint scheduled to occur because of this parameter is delayed until the completion of the previous checkpoint if the previous checkpoint has not yet completed.
-
Recovery I/O can also be limited by setting the
LOG_CHECKPOINT_INTERVALparameter or by the size specified for the smallest redo log. For information on which mechanism is controlling checkpointing behavior, query theV$INSTANCE_RECOVERYview.
See Also:
-
“LOG_CHECKPOINT_TIMEOUT”
-
“V$INSTANCE_RECOVERY”
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Oracle Database
Performance Tuning Guide for information on disabling or removing this parameter when theFAST_START_MTTR_TARGETparameter is set
