本文內容來自YashanDB官網，具體內容請見(https://www.yashandb.com/newsinfo/7488286.html?templateId=1718516)
測試驗證環境說明
測試用例說明
1、相同版本下，新增表資料量，使統計資訊失效。最佳化器優先使用outline的計劃。
2、相同版本下，繫結引數執行場景下，最佳化器優先使用outline的計劃。
3、單機主備環境，最佳化器優先使用outline的計劃。
4、升級資料庫版本後，最佳化器優先使用outline的計劃。
測試過程記錄
點選檢視程式碼
--建兩張普通表test_tab1和test_tab2 並且分佈插入200w資料。
create table test_tab1(col1 int, col2 int, col3 int);
create table test_tab2(col1 int, col2 int, col3 int);
SQL>
Succeed.
SQL>
Succeed.
SQL> begin
for i in 1..2000000 loop
insert into test_tab1 values(i+1,i+2,i+3);
insert into test_tab2 values(i+2,i+3,i+4);
end loop;
commit;
end;
/
PL/SQL Succeed.
-- 收集統計資訊
SQL> exec DBMS_STATS.GATHER_DATABASE_STATS('GATHER AUTO', 1, 16, 'FOR ALL COLUMNS SIZE AUTO', 'AUTO', TRUE, FALSE);
PL/SQL Succeed.
--驗證版本
SQL> select * from v$version;
BANNER VERSION_NUMBER
---------------------------------------------------------------- -----------------
Release 22.2.10.100 x86_64 22.2.10.100
1 row fetched.
SQL> explain select distinct t1.col1, t2.col1
from test_tab1 t1 inner join test_tab2 t2 on t1.col2=t2.col2
order by t1.col1 limit 500;
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 2118027925
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 500| 29542( 0)| |
| 2 | TOP SORT DISTINCT | | | 1999998| 29538( 0)| |
|* 3 | HASH JOIN INNER | | | 1999998| 24350( 0)| |
| 4 | TABLE ACCESS FULL | TEST_TAB1 | SALES | 2000000| 453( 0)| |
| 5 | TABLE ACCESS FULL | TEST_TAB2 | SALES | 2000000| 453( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
3 - Predicate : access("T1"."COL2" = "T2"."COL2")
18 rows fetched.
SQL> create unique index idx1 on test_tab2(col2, col1);
Succeed.
SQL> exec DBMS_STATS.GATHER_DATABASE_STATS('GATHER AUTO', 1, 16, 'FOR ALL COLUMNS SIZE AUTO', 'AUTO', TRUE, FALSE);
PL/SQL Succeed.
-- 建立索引後，從HASH JOIN 轉為NEXTED LOOPS INNER JOIN
SQL> explain select distinct t1.col1, t2.col1
2 from test_tab1 t1 inner join test_tab2 t2 on t1.col2=t2.col2
order by t1.col1 limit 500;
3
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 2118027925
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 500| 7785( 0)| |
| 2 | TOP SORT DISTINCT | | | 1999998| 7781( 0)| |
| 3 | NESTED LOOPS INNER | | | 1999998| 2594( 0)| |
| 4 | TABLE ACCESS FULL | TEST_TAB1 | SALES | 2000000| 453( 0)| |
|* 5 | INDEX RANGE SCAN | IDX1 | SALES | 1| 142( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
5 - Predicate : access("T2"."COL2" = "T1"."COL2")
18 rows fetched.
--刪除索引後，執行計劃從NEXTED LOOPS INNER 轉為 HASH JOIN INNER
SQL> drop index IDX1;
Succeed.
SQL>
explain select distinct t1.col1, t2.col1
from test_tab1 t1 inner join test_tab2 t2 on t1.col2=t2.col2
order by t1.col1 limit 500;
SQL>
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 2118027925
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 500| 29542( 0)| |
| 2 | TOP SORT DISTINCT | | | 1999998| 29538( 0)| |
|* 3 | HASH JOIN INNER | | | 1999998| 24350( 0)| |
| 4 | TABLE ACCESS FULL | TEST_TAB1 | SALES | 2000000| 453( 0)| |
| 5 | TABLE ACCESS FULL | TEST_TAB2 | SALES | 2000000| 453( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
3 - Predicate : access("T1"."COL2" = "T2"."COL2")
18 rows fetched.
-- 建立索引前，增加outline
-- outline 分別是ol_ab和ol_a
SQL> CREATE OUTLINE ol_ab FOR CATEGORY ctgy_ab ON
select distinct t1.col1, t2.col1
from test_tab1 t1 inner join test_tab2 t2 on t1.col2=t2.col2
order by t1.col1 limit 500;
Succeed.
SQL> CREATE OUTLINE ol_a FOR CATEGORY ctgy_ab ON
select /*+ full(t2) */ distinct t1.col1, t 2 3 4 2.col1
from test_tab1 t1 inner join test_tab2 t2 on t1.col2=t2.col2
order by t1.col1 limit 500;
Succeed.
--應用outline，使得配置生效
SQL> ALTER SESSION SET USE_STORED_OUTLINES=ctgy_ab;
Succeed.
-- 整庫收集統計資訊，讓執行計劃重新生成
SQL> exec DBMS_STATS.GATHER_DATABASE_STATS('GATHER AUTO', 1, 16, 'FOR ALL COLUMNS SIZE AUTO', 'AUTO', TRUE, FALSE);
PL/SQL Succeed.
--建立索引
-- 經前面測試得知，建立索引後，此版本資料庫會選擇NEXTED LOOP JOIN
SQL> create unique index idx1 on test_tab2(col2, col1);
Succeed.
-- 可以看到outline已生效，依然走HASH JOIN INNER
SQL> explain select distinct t1.col1, t2.col1
from test_tab1 t1 inner join test_tab2 t2 on t1.col2=t2.col2
order by t1.col1 limit 500;
SQL>
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 2118027925
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 500| 29542( 0)| |
| 2 | TOP SORT DISTINCT | | | 1999998| 29538( 0)| |
|* 3 | HASH JOIN INNER | | | 1999998| 24350( 0)| |
| 4 | TABLE ACCESS FULL | TEST_TAB1 | SALES | 2000000| 453( 0)| |
| 5 | TABLE ACCESS FULL | TEST_TAB2 | SALES | 2000000| 453( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
3 - Predicate : access("T1"."COL2" = "T2"."COL2")
Outline Information :
---------------------------------------------------
- outline OL_AB used for this statement
23 rows fetched.
SQL> SELECT join_pos, hint
FROM USER_OUTLINE_HINTS
WHERE name = 'OL_AB'; 2 3
JOIN_POS HINT
-------- ----------------------------------------------------------------
0 LEADING(T1 T2)
0 USE_HASH(T2)
1 FULL(T1)
2 FULL(T2)
4 rows fetched.
點選檢視程式碼
begin
for i in 2000003 ..4000003 loop
insert into test_tab1 values(i+1,i+2,i+3);
insert into test_tab2 values(i+2,i+3,i+4);
end loop;
commit;
end;
/
點選檢視程式碼
SQL> select * from dba_tab_statistics where STALE_STATS!='N';
OWNER TABLE_NAME PARTITION_NAME PARTITION_POSITION SUBPARTITION_NAME SUBPARTITION_POSITION OBJECT_TYPE NUM_ROWS BLOCKS EMPTY_BLOCKS AVG_SPACE CHAIN_CNT AVG_ROW_LEN SAMPLE_SIZE LAST_ANALYZED GLOBAL_STATS USER_STATS LOCKED_STATS STALE_STATS SCOPE
---------------------------------------------------------------- ---------------------------------------------------------------- ---------------------------------------------------------------- --------------------- ----------------- --------------------- ------------- --------------------- --------------------- --------------------- ------------ --------------------- ------------ --------------------- -------------------------------- ------------ ---------- ------------ ----------- ---------
SALES TEST_TAB1 TABLE 2000000 6007 36 735 0 20 2000000 2024-08-07 Y N N Y SHARED
SALES TEST_TAB2 TABLE 2000000 6039 68 774 0 20 2000000 2024-08-07 Y N N Y SHARED
2 rows fetched.
統計資訊失效後，最佳化器優先使用outline的計劃
點選檢視程式碼
-- outline 沒有生效時，業務查詢的計劃
SQL> explain select distinct t1.col1, t2.col1
from test_tab1 t1 inner join test_tab2 t2 on t1.col2=t2.col2
order by t1.col1 limit 500;
2 3
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 2118027925
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 500| 943( 0)| |
| 2 | TOP SORT DISTINCT | | | 1000| 943( 0)| |
| 3 | NESTED LOOPS INNER | | | 100000| 683( 0)| |
| 4 | TABLE ACCESS FULL | TEST_TAB1 | SALES | 100000| 442( 0)| |
|* 5 | INDEX RANGE SCAN | IDX1 | SALES | 1| 142( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
5 - Predicate : access("T2"."COL2" = "T1"."COL2")
18 rows fetched.
--outline生效後，最佳化器優先使用outline的執行計劃
SQL> ALTER SESSION SET USE_STORED_OUTLINES=ctgy_ab;
Succeed.
SQL> explain select distinct t1.col1, t2.col1
from test_tab1 t1 inner join test_tab2 t2 on t1.col2=t2.col2
order by t1.col1 limit 500;
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 2118027925
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 500| 29542( 0)| |
| 2 | TOP SORT DISTINCT | | | 1999998| 29538( 0)| |
|* 3 | HASH JOIN INNER | | | 1999998| 24350( 0)| |
| 4 | TABLE ACCESS FULL | TEST_TAB1 | SALES | 2000000| 453( 0)| |
| 5 | TABLE ACCESS FULL | TEST_TAB2 | SALES | 2000000| 453( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
3 - Predicate : access("T1"."COL2" = "T2"."COL2")
Outline Information :
---------------------------------------------------
- outline OL_AB used for this statement
23 rows fetched.
繫結引數執行，最佳化器優先使用outline計劃
點選檢視程式碼
--建立繫結引數的outline
CREATE OUTLINE ol_c FOR CATEGORY ctgy_ab ON
select /*+ full(t2)*/ t2.col2,t2.col1 from test_tab2 t2 where t2.col2=? and t2.col1=?;
Succeed.
ALTER system SET USE_STORED_OUTLINES=ctgy_ab;
-- outline生效
SQL> ALTER SESSION SET USE_STORED_OUTLINES=ctgy_ab;
Succeed.
SQL> explain select /*+ full(t2)*/ t2.col2,t2.col1 from test_tab2 t2 where t2.col2=? and t2.col1=?;
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 631693285
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
|* 1 | TABLE ACCESS FULL | TEST_TAB2 | SALES | 1| 448( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
1 - Predicate : filter("T2"."COL2" = Param(:0) AND "T2"."COL1" = Param(:1))
Hint Information :
---------------------------------------------------
full(t2) / rejected by IGNORE_OPTIM_EMBEDDED_HINTS
Outline Information :
---------------------------------------------------
- outline OL_C used for this statement
<details>
<summary>點選檢視程式碼</summary>
</details>
24 rows fetched.
主備資料庫都需要開啟outline功能。
點選檢視程式碼
[yashan@node01 install2210100]$ ./bin/yasboot cluster status -c yashandb -d
hostid | node_type | nodeid | pid | instance_status | database_status | database_role | listen_address | data_path
--------------------------------------------------------------------------------------------------------------------------------------------------
host0001 | db | 1-1:1 | 21925 | open | normal | primary | 192.168.33.103:1688 | /home/yashan/yasdb_data/db-1-1
+-----------+--------+-------+-----------------+-----------------+---------------+---------------------+--------------------------------
| db | 1-2:2 | 21959 | open | normal | standby | 192.168.33.103:1690 | /home/yashan/yasdb_data/db-1-2
----------+-----------+--------+-------+-----------------+-----------------+---------------+---------------------+--------------------------------
[yashan@node01 install2210100]$ yasql sys/yasdb_123@192.168.33.103:1688
YashanDB SQL Release 22.2.10.100 x86_64
Connected to:
YashanDB Server Release 22.2.10.100 x86_64 - X86 64bit Linux
SQL> ALTER SYSTEM SET USE_STORED_OUTLINES=ctgy_ab;
Succeed.
SQL> set autotrace on;
SQL> select distinct t2.col2,t3.col1 from test_tab2 t2 inner join test_tab3 t3 on t2.col2=t3.col1
where t2.col2 =3 limit 10;
COL2 COL1
---------------------------------------------------------------- ----------------------------------------------------------------
3 3
Execution Plan
----------------------------------------------------------------
SQL hash value: 4249347504
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
| Id | Operation type | Name | Owner | E - Rows | A - Rows | Cost(%CPU) | A - Time | Loops | Memory | Disk | Partition info |
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | | | | | | |
| 1 | WINDOW | | | 1| | 2212( 0)| | | | | |
| 2 | SORT DISTINCT | | | 1| | 2212( 0)| | | | | |
|* 3 | NESTED LOOPS INNER | | | 1| | 2212( 0)| | | | | |
|* 4 | INDEX FAST FULL SCAN | IDX_COL2 | SYS | 1| | 929( 0)| | | | | |
| 5 | INDEX FAST FULL SCAN | IDX_COL3 | SYS | 10000000| | 600( 0)| | | | | |
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
3 - Predicate : filter("T2"."COL2" = "T3"."COL1")
4 - Predicate : filter(CAST("T2"."COL2" AS NUMBER) = 3)
Outline Information :
---------------------------------------------------
- outline OL_AF used for this statement
Statistics
----------------------------------------------------------------------------------------------------
25 rows fetched.
SQL>
Disconnected from:
YashanDB Server Release 22.2.10.100 x86_64 - X86 64bit Linux
--備庫上測試outline功能
[yashan@node01 install2210100]$ yasql sys/yasdb_123@192.168.33.103:1690
YashanDB SQL Release 22.2.10.100 x86_64
Connected to:
YashanDB Server Release 22.2.10.100 x86_64 - X86 64bit Linux
SQL> set autotrace on;
SQL> select distinct t2.col2,t3.col1 from test_tab2 t2 inner join test_tab3 t3 on t2.col2=t3.col1
where t2.col2 =3 limit 10;
COL2 COL1
---------------------------------------------------------------- ----------------------------------------------------------------
3 3
Execution Plan
----------------------------------------------------------------
SQL hash value: 4249347504
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
| Id | Operation type | Name | Owner | E - Rows | A - Rows | Cost(%CPU) | A - Time | Loops | Memory | Disk | Partition info |
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | | | | | | |
| 1 | WINDOW | | | 1| | 1071( 0)| | | | | |
| 2 | SORT DISTINCT | | | 1| | 1071( 0)| | | | | |
| 3 | NESTED LOOPS INNER | | | 1| | 1071( 0)| | | | | |
|* 4 | INDEX FAST FULL SCAN | IDX_COL2 | SYS | 1| | 929( 0)| | | | | |
|* 5 | INDEX RANGE SCAN | IDX_COL3 | SYS | 1| | 142( 0)| | | | | |
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
4 - Predicate : filter(CAST("T2"."COL2" AS NUMBER) = 3)
5 - Predicate : access("T3"."COL1" = "T2"."COL2")
Statistics
----------------------------------------------------------------------------------------------------
20 rows fetched.
--備庫需要單獨開啟outline
SQL> ALTER SYSTEM SET USE_STORED_OUTLINES=ctgy_ab;
Succeed.
SQL> select distinct t2.col2,t3.col1 from test_tab2 t2 inner join test_tab3 t3 on t2.col2=t3.col1
where t2.col2 =3 limit 10;
COL2 COL1
---------------------------------------------------------------- ----------------------------------------------------------------
3 3
Execution Plan
----------------------------------------------------------------
SQL hash value: 4249347504
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
| Id | Operation type | Name | Owner | E - Rows | A - Rows | Cost(%CPU) | A - Time | Loops | Memory | Disk | Partition info |
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | | | | | | |
| 1 | WINDOW | | | 1| | 2212( 0)| | | | | |
| 2 | SORT DISTINCT | | | 1| | 2212( 0)| | | | | |
|* 3 | NESTED LOOPS INNER | | | 1| | 2212( 0)| | | | | |
|* 4 | INDEX FAST FULL SCAN | IDX_COL2 | SYS | 1| | 929( 0)| | | | | |
| 5 | INDEX FAST FULL SCAN | IDX_COL3 | SYS | 10000000| | 600( 0)| | | | | |
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
3 - Predicate : filter("T2"."COL2" = "T3"."COL1")
4 - Predicate : filter(CAST("T2"."COL2" AS NUMBER) = 3)
Outline Information :
---------------------------------------------------
- outline OL_AF used for this statement
Statistics
----------------------------------------------------------------------------------------------------
25 rows fetched.
升級資料庫版本後，最佳化器優先使用outline為準
22.2.10.100 版本執行計劃和建立outline al_af
點選檢視程式碼
YashanDB Server Release 22.2.10.100 x86_64 - X86 64bit Linux
create table test_tab2(col1 varchar2(100),col2 varchar2(100),col3 varchar2(100));
create table test_tab3(col1 varchar2(100),col2 varchar2(100),col3 varchar2(100));
SQL>
Succeed.
Succeed.
SQL>
SQL>
begin
for i in 1..10000000 loop
insert into test_tab2 values(i+1,i+2,i+3);
insert into test_tab3 values(i+2,i+3,i+4);
end loop;
commit;
end;
/
SQL>
PL/SQL Succeed.
SQL> exec DBMS_STATS.GATHER_DATABASE_STATS('GATHER AUTO', 1, 16, 'FOR ALL COLUMNS SIZE AUTO', 'AUTO', TRUE, FALSE);
PL/SQL Succeed.
create index idx_col2 on test_tab2(col2);
create index idx_col3 on test_tab3(col1);
SQL>
Succeed.
SQL>
Succeed.
SQL> explain select distinct t2.col2,t3.col1 from test_tab2 t2 inner join test_tab3 t3 on t2.col2=t3.col1
where t2.col2 =3 limit 10;
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 4249347504
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 1| 1071( 0)| |
| 2 | SORT DISTINCT | | | 1| 1071( 0)| |
| 3 | NESTED LOOPS INNER | | | 1| 1071( 0)| |
|* 4 | INDEX FAST FULL SCAN | IDX_COL2 | SYS | 1| 929( 0)| |
|* 5 | INDEX RANGE SCAN | IDX_COL3 | SYS | 1| 142( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
4 - Predicate : filter(CAST("T2"."COL2" AS NUMBER) = 3)
5 - Predicate : access("T3"."COL1" = "T2"."COL2")
19 rows fetched.
SQL> exec DBMS_STATS.GATHER_DATABASE_STATS('GATHER AUTO', 1, 16, 'FOR ALL COLUMNS SIZE AUTO', 'AUTO', TRUE, FALSE);
PL/SQL Succeed.
SQL> explain select distinct t2.col2,t3.col1 from test_tab2 t2 inner join test_tab3 t3 on t2.col2=t3.col1
where t2.col2 =3 limit 10;
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 4249347504
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 1| 1071( 0)| |
| 2 | SORT DISTINCT | | | 1| 1071( 0)| |
| 3 | NESTED LOOPS INNER | | | 1| 1071( 0)| |
|* 4 | INDEX FAST FULL SCAN | IDX_COL2 | SYS | 1| 929( 0)| |
|* 5 | INDEX RANGE SCAN | IDX_COL3 | SYS | 1| 142( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
4 - Predicate : filter(CAST("T2"."COL2" AS NUMBER) = 3)
5 - Predicate : access("T3"."COL1" = "T2"."COL2")
19 rows fetched.
SQL> CREATE OUTLINE ol_af FOR CATEGORY ctgy_ab ON
select distinct t2.col2,t3.col1 from test_tab2 t2 inner join test_tab3 t3 on t2.col2=t3.col1
where t2.col2 =3 limit 10;
Succeed.
SQL>
ALTER SESSION SET USE_STORED_OUTLINES=ctgy_ab;
SQL>
Succeed.
SQL> explain select distinct t2.col2,t3.col1 from test_tab2 t2 inner join test_tab3 t3 on t2.col2=t3.col1
where t2.col2 =3 limit 10;
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 4249347504
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 1| 2212( 0)| |
| 2 | SORT DISTINCT | | | 1| 2212( 0)| |
|* 3 | NESTED LOOPS INNER | | | 1| 2212( 0)| |
|* 4 | INDEX FAST FULL SCAN | IDX_COL2 | SYS | 1| 929( 0)| |
| 5 | INDEX FAST FULL SCAN | IDX_COL3 | SYS | 10000000| 600( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
3 - Predicate : filter("T2"."COL2" = "T3"."COL1")
4 - Predicate : filter(CAST("T2"."COL2" AS NUMBER) = 3)
Outline Information :
---------------------------------------------------
- outline OL_AF used for this statement
24 rows fetched.
點選檢視程式碼
SQL> select * from v$version;
BANNER VERSION_NUMBER
---------------------------------------------------------------- -----------------
Enterprise Edition Release 23.2.3.100 x86_64 23.2.3.100
YashanDB Server Enterprise Edition Release 23.2.3.100 x86_64 - X86 64bit Linux
SQL> explain
select distinct t2.col2,t3.col1 from test_tab2 t2 inner join test_tab3 t3 on t2.col2=t3.col1
where t2.col2 =3 limit 10;
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 4249347504
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 1| 29( 0)| |
| 2 | SORT DISTINCT | | | 1| 29( 0)| |
| 3 | NESTED INDEX LOOPS INNER | | | 1| 29( 0)| |
|* 4 | INDEX FAST FULL SCAN | IDX_COL2 | SYS | 1| 28( 0)| |
|* 5 | INDEX RANGE SCAN | IDX_COL3 | SYS | 1| 1( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
1 - Limit Expression: (LIMIT: 10)
2 - Distinct Expression: ("T2"."COL2")
4 - Predicate : filter("T2"."COL2" = 3)
5 - Predicate : access("T3"."COL1" = "T2"."COL2")
21 rows fetched.
SQL>
exec DBMS_STATS.GATHER_DATABASE_STATS('GATHER AUTO', 1, 16, 'FOR ALL COLUMNS SIZE AUTO', 'AUTO', TRUE, FALSE);
SQL>
PL/SQL Succeed.
SQL>
ALTER SESSION SET USE_STORED_OUTLINES=ctgy_ab;
Succeed.
SQL> explain select distinct t2.col2,t3.col1 from test_tab2 t2 inner join test_tab3 t3 on t2.col2=t3.col1
where t2.col2 =3 limit 10;
PLAN_DESCRIPTION
----------------------------------------------------------------
SQL hash value: 4249347504
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| Id | Operation type | Name | Owner | Rows | Cost(%CPU) | Partition info |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | |
| 1 | WINDOW | | | 1| 767( 0)| |
| 2 | SORT DISTINCT | | | 1| 767( 0)| |
|* 3 | NESTED LOOPS INNER | | | 1| 767( 0)| |
|* 4 | INDEX FAST FULL SCAN | IDX_COL2 | SYS | 1| 28( 0)| |
| 5 | INDEX FAST FULL SCAN | IDX_COL3 | SYS | 10000000| 28( 0)| |
+----+--------------------------------+----------------------+------------+----------+-------------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
1 - Limit Expression: (LIMIT: 10)
2 - Distinct Expression: ("T2"."COL2")
3 - Predicate : filter("T2"."COL2" = "T3"."COL1")
4 - Predicate : filter("T2"."COL2" = 3)
Outline Information :
---------------------------------------------------
- outline OL_AF used for this statement
26 rows fetched.
SQL> set autotrace on;
SQL> select distinct t2.col2,t3.col1 from test_tab2 t2 inner join test_tab3 t3 on t2.col2=t3.col1
where t2.col2 =3 limit 10;
2
COL2 COL1
---------------------------------------------------------------- ----------------------------------------------------------------
3 3
Execution Plan
----------------------------------------------------------------
SQL hash value: 4249347504
Optimizer: ADOPT_C
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
| Id | Operation type | Name | Owner | E - Rows | A - Rows | Cost(%CPU) | A - Time | Loops | Memory | Disk | Partition info |
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
| 0 | SELECT STATEMENT | | | | | | | | | | |
| 1 | WINDOW | | | 1| | 767( 0)| | | | | |
| 2 | SORT DISTINCT | | | 1| | 767( 0)| | | | | |
|* 3 | NESTED LOOPS INNER | | | 1| | 767( 0)| | | | | |
|* 4 | INDEX FAST FULL SCAN | IDX_COL2 | SYS | 1| | 28( 0)| | | | | |
| 5 | INDEX FAST FULL SCAN | IDX_COL3 | SYS | 10000000| | 28( 0)| | | | | |
+----+--------------------------------+----------------------+------------+----------+----------+-------------+----------+----------+----------+----------+--------------------------------+
Operation Information (identified by operation id):
---------------------------------------------------
1 - Limit Expression: (LIMIT: 10)
2 - Distinct Expression: ("T2"."COL2")
3 - Predicate : filter("T2"."COL2" = "T3"."COL1")
4 - Predicate : filter("T2"."COL2" = 3)
Outline Information :
---------------------------------------------------
- outline OL_AF used for this statement
Statistics
----------------------------------------------------------------------------------------------------
27 rows fetched.
測試總結
