Oracle introduced this view in version 10. It looks like this in version 11:
SQL> desc dba_feature_usage_statistics
Name Null? Type
-------------------------- -------- ------------------
DBID NOT NULL NUMBER
NAME NOT NULL VARCHAR2(64)
VERSION NOT NULL VARCHAR2(17)
DETECTED_USAGES NOT NULL NUMBER
TOTAL_SAMPLES NOT NULL NUMBER
CURRENTLY_USED VARCHAR2(5)
FIRST_USAGE_DATE DATE
LAST_USAGE_DATE DATE
AUX_COUNT NUMBER
FEATURE_INFO CLOB
LAST_SAMPLE_DATE DATE
LAST_SAMPLE_PERIOD NUMBER
SAMPLE_INTERVAL NUMBER
DESCRIPTION VARCHAR2(128)
SQL>
As its name suggests, it allows you to see if a database uses a particular Oracle feature or not. In Oracle 11, it has over 150 entries:
SQL> l
1 select count(*)
2* from dba_feature_usage_statistics
SQL> /
COUNT(*)
----------
152
SQL>
Some of the features reported are shown below:
SQL> l
1* select name from dba_feature_usage_statistics
SQL> /
NAME
-------------------------------------------------------
Encrypted Tablespaces
MTTR Advisor
Multiple Block Sizes
OLAP - Analytic Workspaces
OLAP - Cubes
Oracle Managed Files
Oracle Secure Backup
Parallel SQL DDL Execution
Parallel SQL DML Execution
Parallel SQL Query Execution
Partitioning (system)
Partitioning (user)
Oracle Text
PL/SQL Native Compilation
Real Application Clusters (RAC)
Recovery Area
Recovery Manager (RMAN)
RMAN - Disk Backup
RMAN - Tape Backup
Etc
I checked in a database where I did not think that SQL Loader had been used with the Direct Path option. The value in the DETECTED_USAGES column was zero:
SQL> l
1 select detected_usages
2 from dba_feature_usage_statistics
3 where name =
4* 'Oracle Utility SQL Loader (Direct Path Load)'
SQL> /
DETECTED_USAGES
---------------
0
SQL>
I checked in a database where I had used SQL Loader with the Direct Path option a few times. The value in the DETECTED_USAGES column seemed far too high:
SQL> l
1 select detected_usages
2 from dba_feature_usage_statistics
3 where name =
4* 'Oracle Utility SQL Loader (Direct Path Load)'
SQL> /
DETECTED_USAGES
---------------
231
SQL>
I will do some research and once I know how this figure is calculated, I will return to this post and update it.
