oracle优化器版本
SELECT value FROM v$parameter_valid_values WHERE name = 'optimizer_features_enable';
VALUE
--------------------------------------------------------------------------------
8.0.0
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.1.0
8.1.3
8.1.4
8.1.5
8.1.6
8.1.7
9.0.0
9.0.1
9.2.0
9.2.0.8
10.1.0
10.1.0.3
10.1.0.4
10.1.0.5
10.2.0.1
10.2.0.2
10.2.0.3
10.2.0.4
10.2.0.5
11.1.0.6
11.1.0.7
11.2.0.1
11.2.0.2
11.2.0.3
11.2.0.3.1
31 rows selected.
SQL> show parameter optimizer
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
optimizer_capture_sql_plan_baselines boolean FALSE
optimizer_dynamic_sampling integer 2
optimizer_features_enable string 11.2.0.3
optimizer_index_caching integer 90
optimizer_index_cost_adj integer 25
optimizer_mode string ALL_ROWS
optimizer_secure_view_merging boolean TRUE
optimizer_use_invisible_indexes boolean FALSE
optimizer_use_pending_statistics boolean FALSE
optimizer_use_sql_plan_baselines boolean TRUE
SQL>
VALUE
--------------------------------------------------------------------------------
8.0.0
8.0.3
8.0.4
8.0.5
8.0.6
8.0.7
8.1.0
8.1.3
8.1.4
8.1.5
8.1.6
8.1.7
9.0.0
9.0.1
9.2.0
9.2.0.8
10.1.0
10.1.0.3
10.1.0.4
10.1.0.5
10.2.0.1
10.2.0.2
10.2.0.3
10.2.0.4
10.2.0.5
11.1.0.6
11.1.0.7
11.2.0.1
11.2.0.2
11.2.0.3
11.2.0.3.1
31 rows selected.
系统设计时应尽量避免出现left outer join, right outer join
/*+ optimizer_features_enable('10.1.0') */SQL> show parameter optimizer
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
optimizer_capture_sql_plan_baselines boolean FALSE
optimizer_dynamic_sampling integer 2
optimizer_features_enable string 11.2.0.3
optimizer_index_caching integer 90
optimizer_index_cost_adj integer 25
optimizer_mode string ALL_ROWS
optimizer_secure_view_merging boolean TRUE
optimizer_use_invisible_indexes boolean FALSE
optimizer_use_pending_statistics boolean FALSE
optimizer_use_sql_plan_baselines boolean TRUE
SQL>