DBA_HIST_CR_BLOCK_SERVER

DBA_HIST_CR_BLOCK_SERVER displays historical statistics on the Global Cache Service processes (lMS) used in cache fusion. This view contains snapshots of V$CR_BLOCK_SERVER.

Column Datatype NULL Description
SNAP_ID NUMBER NOT NULL Unique snapshot ID
DBID NUMBER NOT NULL Database ID for the snapshot
INSTANCE_NUMBER NUMBER NOT NULL Instance number for the snapshot
CR_REQUESTS NUMBER   Number of CR blocks served due to remote CR block requests
CURRENT_REQUESTS NUMBER   Number of current blocks served due to remote CR block requests

CR_REQUESTS + CURRENT_REQUESTS = global cache CR blocks served (from V$SYSSTAT).

DATA_REQUESTS NUMBER   Number of current or CR requests for data blocks
UNDO_REQUESTS NUMBER   Number of CR requests for undo blocks
TX_REQUESTS NUMBER   Number of CR requests for undo segment header blocks

DATA_REQUESTS + UNDO_REQUESTS + TX_REQUESTS = total number of requests handled by the LMS processes

CURRENT_RESULTS NUMBER   Number of requests for which no changes were rolled out of the block returned to the requesting instance
PRIVATE_RESULTS NUMBER   Number of requests for which changes were rolled out of the block returned to the requesting instance, and only the requesting transaction can use the resulting CR block
ZERO_RESULTS NUMBER   Number of requests for which changes were rolled out of the block returned to the requesting instance. Only zero-XID transactions can use the block.
DISK_READ_RESULTS NUMBER   Number of requests for which the requesting instance had to read the requested block from disk
FAIL_RESULTS NUMBER   Number of requests that failed; the requesting transaction must reissue the request
FAIRNESS_DOWN_CONVERTS NUMBER   Number of times an instance receiving a request has down-converted an X lock on a block because it was not modifying the block
FAIRNESS_CLEARS NUMBER   Number of times the fairness counter was cleared. This counter tracks the number of times a block was modified after it was served.
FREE_GC_ELEMENTS NUMBER   Number of times a request was received from another instance and the X lock had no buffers
FLUSHES NUMBER   Number of times the log has been flushed by an LMS process
FLUSHES_QUEUED NUMBER   Number of flushes queued by an LMS process
FLUSH_QUEUE_FULL NUMBER   Number of times the flush queue was full
FLUSH_MAX_TIME NUMBER   Maximum time for flush
LIGHT_WORKS NUMBER   Number of times the light-work rule was evoked. This rule prevents the LMS processes from going to disk while responding to CR requests for data, undo, or undo segment header blocks. This rule can prevent the LMS process from completing its response to the CR request.
ERRORS NUMBER   Number of times an error was signalled by an LMS process