Smart Flash Cache and Smart Flash Logging - Oracle Exadata Recipes: A Problem-Solution Approach - page 533

from
(select * from
(select obj#,dataobj#,statistic_name,value
from v$segstat) pivot
(sum(value) for (statistic_name) in
('optimized physical reads' as opr,
'physical reads' as pr))) segstat,
(select owner,object_name,object_id,data_object_id
from dba_objects
where owner=upper('&&owner') and object_name=upper('&&object_name')) obj
where segstat.obj#=obj.object_id
and segstat.dataobj#=obj.data_object_id;
Enter value for owner: PO
Enter value for object_name: RCV_TRANSACTIONS
Owner Object PhysReads OptPhysReads %FlashReads
---------- ----------------- ---------- ------------ -----------
PO RCV_TRANSACTIONS 17602 2 0.01
Historical segment statistics from AWR
SnapTime Owner Object PhysReads OptPhysReads %FlashReads
------------------- ------- ----------------- ---------- ------------ -----------
18-NOV-12 23:49 PO RCV_TRANSACTIONS 175984 24 0.01
19-NOV-12 00:00 PO RCV_TRANSACTIONS 70900 122 0.17
Measuring Flash Cache with Storage Server Metrics
Recipe 13-3 in Chapter 13 introduces the topic of monitoring Exadata with storage server metrics. Exadata provides a
number of Smart Flash Cache and Smart Flash Logging metrics with the FLASHCACHE and FLASHLOG objectTypes . To
list the available flash cache metrics and their descriptions, execute the following command from CellCLI:
CellCLI> list metricdefinition where objectType='FLASHCACHE' attributes name,description
... Output omitted for brevity
FC_BYKEEP_USED "Number of megabytes used for 'keep' objects on FlashCache"
FC_BY_USED "Number of megabytes used on FlashCache"
FC_IO_BYKEEP_R "Number of megabytes read from FlashCache for 'keep' objects"
... Output omitted for brevity
CellCLI>
There are a number of flash cache metrics that you may find worthwhile to monitor; the following example shows
just one, the number of I/O requests satisfied from flash cache since the storage cell has started and Smart Flash
Cache has been created:
CellCLI> list metriccurrent where name='FC_IO_RQ_R'
FC_IO_RQ_R FLASHCACHE 34,505,666 IO requests
CellCLI>