gc current grant 2-way
Definition
- An instance request any data block in CURRENT MODE for dml(current) from Master.
- If the data block is not cached on any instance even on master too, then master instance will send a message to the requesting instance granting the EXCLUSIVE lock.
- Meanwhile requesting instance will wait in "GC CURRENT BLOCK 2-WAY"
- Requesting instace will read data block from disk and do the physical I/O.
- This wait event does not indicate any contention.
Reason
- This wait event appears in "TOP-5" timed events section of AWR Report.
- This wait event represent that requesting instance is spending a significant amount of time in obtaining the locks.
- Interconnect is having N/W latency (rare).
Troubleshooting
- Best Solution is to tune your SQL Application so that it request less amout of data blocks.
- Because if requesting instance ask for more data blocks then master has to locking and holding instance related information in GRD before granting EXCLUSIVE LOCK, which will be high.
- Tune Interconnect (very rare).
Definition
- An instance request any data block in CURRENT MODE for dml(current) from Master.
- If the data block is not cached on any instance even on master too, then master instance will send a message to the requesting instance granting the EXCLUSIVE lock.
- Meanwhile requesting instance will wait in "GC CURRENT BLOCK 2-WAY"
- Requesting instace will read data block from disk and do the physical I/O.
- This wait event does not indicate any contention.
Reason
- This wait event appears in "TOP-5" timed events section of AWR Report.
- This wait event represent that requesting instance is spending a significant amount of time in obtaining the locks.
- Interconnect is having N/W latency (rare).
Troubleshooting
- Best Solution is to tune your SQL Application so that it request less amout of data blocks.
- Because if requesting instance ask for more data blocks then master has to locking and holding instance related information in GRD before granting EXCLUSIVE LOCK, which will be high.
- Tune Interconnect (very rare).
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