Long Table Scan Ratio (LongScanRatio)

The LongTableScanRatio parameter reports the percentage of table scans that are full long table scans. Long tables are defined by Oracle as tables that the buffer manager is not attempting to cache, either because their cache attribute is not set or because too much of the buffer pool is already allocated to such objects.
 Many applications are designed to perform frequent full table scans on the assumption (or under the performance requirement) that the tables will be cached. This parameter helps the DBA to assess whether or not this objective is being met.

Recommendations

On excessive values, evaluate the value of the init.ora small_table_threshold parameter. A large number of full table scans on large tables can seriously affect performance.

BMC PATROL properties

Attribute	Default value
Application class	ORACLE_ENVIRONMENT
Command type	not applicable
Platform	all
Icon style	Graph
Unit	percentage of table scans
Border range	undefined
Alarm1 range	undefined
Alarm2 range	undefined
Scheduling(poll time)	poll time of collector
Active at installation	Yes
Parameter type	Consumer
Value set by	CollEnvironment

BMC ProactiveNet Performance Management properties

Attribute	Default value
Monitor type	Oracle Database Environment
Key Performance Indicator	No
Monitor for abnormalities	Yes
Graph by default	No
Availability	No
Response time	No
Normal distribution	Yes
Statistical	Yes