RECOVERY_ESTIMATED_IOS |
NUMBER |
Contains the number of dirty buffers in the buffer cache. In the Standard Edition, this column is always NULL . |
ACTUAL_REDO_BLKS |
NUMBER |
The current actual number of redo blocks required for recovery |
TARGET_REDO_BLKS |
NUMBER |
The current target number of redo blocks that must be processed for recovery. This value is the minimum value of the following 3 columns, and identifies which of the 3 user-defined limits determines checkpointing. |
LOG_FILE_SIZE_REDO_BLKS |
NUMBER |
Maximum number of redo blocks required to guarantee that a log switch does not occur before the checkpoint completes. |
LOG_CHKPT_TIMEOUT_REDO_BLKS |
NUMBER |
Number of redo blocks that need to be processed during recovery to satisfy the LOG_CHECKPOINT_TIMEOUT parameter. The value displayed is not meaningful unless that parameter has been set. |
LOG_CHKPT_INTERVAL_REDO_BLKS |
NUMBER |
Number of redo blocks that need to be processed during recovery to satisfy the LOG_CHECKPOINT_INTERVAL parameter. The value displayed is not meaningful unless that parameter has been set. |
FAST_START_IO_TARGET_REDO_BLKS |
NUMBER |
This column is obsolete and maintained only for compatibility reasons. The value of this column is always NULL . |
TARGET_MTTR |
NUMBER |
Effective MTTR (mean time to recover) target value in seconds. The TARGET_MTTR value is calculated based on the value of the FAST_START_MTTR_TARGET parameter (the TARGET_MTTR value is used internally), and is usually an approximation of the parameter's value. However, if the FAST_START_MTTR_TARGET parameter value is very small (for example, one second), or very large (for example, 3600 seconds), the calculation will produce a target value dictated by system limitations. In such cases, the TARGET_MTTR value will be the shortest calculated time, or the longest calculated time that recovery is expected to take.
If FAST_START_MTTR_TARGET is not specified, the value of this field is the current estimated MTTR. |
ESTIMATED_MTTR |
NUMBER |
The current estimated mean time to recover (MTTR) based on the number of dirty buffers and log blocks (0 if FAST_START_MTTR_TARGET is not specified). Basically, this value tells you how long you could expect recovery to take based on the work your system is doing right now. |
CKPT_BLOCK_WRITES |
NUMBER |
Number of blocks written by checkpoint writes |