• X Oracle 11g为SQL生成合适执行计划并固定


    ------------恢复内容开始------------


    1.查询当前SQL执行计划并固定


    (1)查询指定SQL SQL_ID 

    SQL> select sql_id,sql_text,version_count,parse_calls from v$sqlarea where sql_text like '%fundinfo%';

    SQL_ID SQL_TEXT VERSION_COUNT PARSE_CALLS
    ------------- -------------------------------------------------------------------------------- ------------- -----------
    6v57a84f59hqk select count(planid) from fundinfo where planid < 99000014000800382760 1 1
    adz60h2w2js6p select sql_id,sql_text,version_count,parse_calls from v$sqlarea where sql_text l 1 1

    (2)查询SQL_ID对应执行计划 

    # 使用下面两种查询一种查询出对应执行计划即可

    SQL> select * from table(dbms_xplan.display_cursor('6v57a84f59hqk'));

    PLAN_TABLE_OUTPUT
    --------------------------------------------------------------------------------
    SQL_ID 6v57a84f59hqk, child number 0
    -------------------------------------
    select count(planid) from fundinfo where planid < 99000014000800382760
    Plan hash value: 913026973
    ---------------------------------------
    | Id | Operation | Name |
    ---------------------------------------
    | 0 | SELECT STATEMENT | |
    | 1 | SORT AGGREGATE | |
    |* 2 | TABLE ACCESS FULL| FUNDINFO |
    ---------------------------------------
    Predicate Information (identified by operation id):
    ---------------------------------------------------
    2 - filter(TO_NUMBER("PLANID")<99000014000800382760)
    Note
    PLAN_TABLE_OUTPUT
    --------------------------------------------------------------------------------
    -----
    - rule based optimizer used (consider using cbo)

    23 rows selected

    SQL> SELECT hash_value,sql_id,plan_hash_value,operation,options FROM v$sql_plan WHERE sql_id='6v57a84f59hqk';

    HASH_VALUE SQL_ID PLAN_HASH_VALUE OPERATION OPTIONS
    ---------- ------------- --------------- ------------------------------ ------------------------------
    475316946 6v57a84f59hqk 913026973 SELECT STATEMENT
    475316946 6v57a84f59hqk 913026973 SORT AGGREGATE
    475316946 6v57a84f59hqk 913026973 TABLE ACCESS FULL



    (3)固定执行计划

    SQL> var test number
    SQL> begin
    2 :test := dbms_spm.load_plans_from_cursor_cache(sql_id=>'6v57a84f59hqk', plan_hash_value=>913026973);
    3 end;
    4 /

    PL/SQL procedure successfully completed

    SQL> select sql_handle, plan_name, origin from dba_sql_plan_baselines;

    SQL_HANDLE PLAN_NAME ORIGIN
    ------------------------------ ------------------------------ --------------
    SQL_458606bd5b57f1c3 SQL_PLAN_4b1h6rpdpgwf36b969528 MANUAL-LOAD


    2.使用HINT生成指定的执行计划


    (1)使用/*+ INDEX(table_name index_name)+*/生成执行计划

    HR@honor1 > select /*+ INDEX(FUNDINFO FUNDINFO_PLANID)+*/ count(planid) from fundinfo where planid < 99000014000800382760;

    COUNT(PLANID)
    ----------------------------------------
    337473
    (2)查询生成的执行计划

    SQL> select sql_id,sql_text,version_count,parse_calls from v$sqlarea where sql_text like '%fundinfo%';

    SQL_ID SQL_TEXT VERSION_COUNT PARSE_CALLS
    ------------- -------------------------------------------------------------------------------- ------------- -----------
    gw6gd2ggk0h9m select /*+ INDEX(FUNDINFO FUNDINFO_PLANID)+*/ count(planid) from fundinfo where 1 1
    adz60h2w2js6p select sql_id,sql_text,version_count,parse_calls from v$sqlarea where sql_text l 1 3

    SQL> SELECT hash_value,sql_id,plan_hash_value,operation,options FROM v$sql_plan WHERE sql_id='gw6gd2ggk0h9m';

    HASH_VALUE SQL_ID PLAN_HASH_VALUE OPERATION OPTIONS
    ---------- ------------- --------------- ------------------------------ ------------------------------
    3743433011 gw6gd2ggk0h9m 2614089935 SELECT STATEMENT
    3743433011 gw6gd2ggk0h9m 2614089935 SORT AGGREGATE
    3743433011 gw6gd2ggk0h9m 2614089935 INDEX FULL SCAN

    3.使用dbms_spm.load_plans_from_cursor_cache函数固定执行计划


    # 说明
    begin
    :test := dbms_spm.load_plans_from_cursor_cache(
    sql_id => '加入HINT后的SQL_ID',
    plan_hash_value => 加入HINT后生成的plan_hash_value,
    sql_handle => '旧的执行计划固定后dba_sql_plan_baselines中sql_handle');
    end;
    /

    # 执行
    SQL> begin
    2 :test := dbms_spm.load_plans_from_cursor_cache(
    3 sql_id => 'gw6gd2ggk0h9m',
    4 plan_hash_value => 2614089935,
    5 sql_handle => 'SQL_458606bd5b57f1c3');
    6 end;
    7 /

    PL/SQL procedure successfully completed

    # 查询基线
    SYS@honor1 > select sql_handle, plan_name, origin from dba_sql_plan_baselines;

    SQL_HANDLE PLAN_NAME ORIGIN
    ------------------------------ ------------------------------ --------------
    SQL_458606bd5b57f1c3 SQL_PLAN_4b1h6rpdpgwf3686e388b MANUAL-LOAD
    SQL_458606bd5b57f1c3 SQL_PLAN_4b1h6rpdpgwf36b969528 MANUAL-LOAD


    4.删除最开始固定的旧基线,使新的执行计划的新基线生效
    SQL> var test number;
    SQL> begin
    2 :test := dbms_spm.drop_sql_plan_baseline(sql_handle=>'SQL_458606bd5b57f1c3', plan_name=>'SQL_PLAN_4b1h6rpdpgwf36b969528');
    3 end;
    4 /

    PL/SQL procedure successfully completed

    # 查询基线

    SYS@honor1 > select sql_handle, plan_name, origin from dba_sql_plan_baselines;

    SQL_HANDLE PLAN_NAME ORIGIN
    ------------------------------ ------------------------------ --------------
    SQL_458606bd5b57f1c3 SQL_PLAN_4b1h6rpdpgwf3686e388b MANUAL-LOAD


    5.测试新基线
    HR@honor1 > explain plan for select count(planid) from fundinfo where planid < 99000014000800382760;

    Explained.

    HR@honor1 > select * from table(dbms_xplan.display);

    PLAN_TABLE_OUTPUT
    ------------------------------------------------------------------------------------------------------------------------
    Plan hash value: 2614089935

    ------------------------------------------------------------------------------------
    | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
    ------------------------------------------------------------------------------------
    | 0 | SELECT STATEMENT | | 1 | 22 | 27 (4)| 00:00:01 |
    | 1 | SORT AGGREGATE | | 1 | 22 | | |
    |* 2 | INDEX FULL SCAN| FUNDINFO_PLANID | 18023 | 387K| 27 (4)| 00:00:01 |
    ------------------------------------------------------------------------------------

    Predicate Information (identified by operation id):
    ---------------------------------------------------

    2 - filter(TO_NUMBER("PLANID")<99000014000800382760)

    Note
    -----
    - SQL plan baseline "SQL_PLAN_4b1h6rpdpgwf3686e388b" used for this statement

    18 rows selected.

    # 可以看到走了索引全扫描,新基线已经生效。


    6.删除基线
    SYS@honor1 > select sql_handle, plan_name, origin from dba_sql_plan_baselines;

    SQL_HANDLE PLAN_NAME ORIGIN
    ------------------------------ ------------------------------ --------------
    SQL_458606bd5b57f1c3 SQL_PLAN_4b1h6rpdpgwf37d78711b AUTO-CAPTURE

    var test number;
    begin
    :test := dbms_spm.drop_sql_plan_baseline(sql_handle=>'SQL_458606bd5b57f1c3', plan_name=>'SQL_PLAN_4b1h6rpdpgwf37d78711b');
    end;
    /

    PL/SQL procedure successfully completed.

    SYS@honor1 > select sql_handle, plan_name, origin from dba_sql_plan_baselines;

    no rows selected


    参考文档:
    https://www.cnblogs.com/ddzj01/p/11377049.html

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    ------------恢复内容开始------------


    1.查询当前SQL执行计划并固定


    (1)查询指定SQL SQL_ID 

    SQL> select sql_id,sql_text,version_count,parse_calls from v$sqlarea where sql_text like '%fundinfo%';

    SQL_ID SQL_TEXT VERSION_COUNT PARSE_CALLS
    ------------- -------------------------------------------------------------------------------- ------------- -----------
    6v57a84f59hqk select count(planid) from fundinfo where planid < 99000014000800382760 1 1
    adz60h2w2js6p select sql_id,sql_text,version_count,parse_calls from v$sqlarea where sql_text l 1 1

    (2)查询SQL_ID对应执行计划 

    # 使用下面两种查询一种查询出对应执行计划即可

    SQL> select * from table(dbms_xplan.display_cursor('6v57a84f59hqk'));

    PLAN_TABLE_OUTPUT
    --------------------------------------------------------------------------------
    SQL_ID 6v57a84f59hqk, child number 0
    -------------------------------------
    select count(planid) from fundinfo where planid < 99000014000800382760
    Plan hash value: 913026973
    ---------------------------------------
    | Id | Operation | Name |
    ---------------------------------------
    | 0 | SELECT STATEMENT | |
    | 1 | SORT AGGREGATE | |
    |* 2 | TABLE ACCESS FULL| FUNDINFO |
    ---------------------------------------
    Predicate Information (identified by operation id):
    ---------------------------------------------------
    2 - filter(TO_NUMBER("PLANID")<99000014000800382760)
    Note
    PLAN_TABLE_OUTPUT
    --------------------------------------------------------------------------------
    -----
    - rule based optimizer used (consider using cbo)

    23 rows selected

    SQL> SELECT hash_value,sql_id,plan_hash_value,operation,options FROM v$sql_plan WHERE sql_id='6v57a84f59hqk';

    HASH_VALUE SQL_ID PLAN_HASH_VALUE OPERATION OPTIONS
    ---------- ------------- --------------- ------------------------------ ------------------------------
    475316946 6v57a84f59hqk 913026973 SELECT STATEMENT
    475316946 6v57a84f59hqk 913026973 SORT AGGREGATE
    475316946 6v57a84f59hqk 913026973 TABLE ACCESS FULL



    (3)固定执行计划

    SQL> var test number
    SQL> begin
    2 :test := dbms_spm.load_plans_from_cursor_cache(sql_id=>'6v57a84f59hqk', plan_hash_value=>913026973);
    3 end;
    4 /

    PL/SQL procedure successfully completed

    SQL> select sql_handle, plan_name, origin from dba_sql_plan_baselines;

    SQL_HANDLE PLAN_NAME ORIGIN
    ------------------------------ ------------------------------ --------------
    SQL_458606bd5b57f1c3 SQL_PLAN_4b1h6rpdpgwf36b969528 MANUAL-LOAD


    2.使用HINT生成指定的执行计划


    (1)使用/*+ INDEX(table_name index_name)+*/生成执行计划

    HR@honor1 > select /*+ INDEX(FUNDINFO FUNDINFO_PLANID)+*/ count(planid) from fundinfo where planid < 99000014000800382760;

    COUNT(PLANID)
    ----------------------------------------
    337473
    (2)查询生成的执行计划

    SQL> select sql_id,sql_text,version_count,parse_calls from v$sqlarea where sql_text like '%fundinfo%';

    SQL_ID SQL_TEXT VERSION_COUNT PARSE_CALLS
    ------------- -------------------------------------------------------------------------------- ------------- -----------
    gw6gd2ggk0h9m select /*+ INDEX(FUNDINFO FUNDINFO_PLANID)+*/ count(planid) from fundinfo where 1 1
    adz60h2w2js6p select sql_id,sql_text,version_count,parse_calls from v$sqlarea where sql_text l 1 3

    SQL> SELECT hash_value,sql_id,plan_hash_value,operation,options FROM v$sql_plan WHERE sql_id='gw6gd2ggk0h9m';

    HASH_VALUE SQL_ID PLAN_HASH_VALUE OPERATION OPTIONS
    ---------- ------------- --------------- ------------------------------ ------------------------------
    3743433011 gw6gd2ggk0h9m 2614089935 SELECT STATEMENT
    3743433011 gw6gd2ggk0h9m 2614089935 SORT AGGREGATE
    3743433011 gw6gd2ggk0h9m 2614089935 INDEX FULL SCAN

    3.使用dbms_spm.load_plans_from_cursor_cache函数固定执行计划


    # 说明
    begin
    :test := dbms_spm.load_plans_from_cursor_cache(
    sql_id => '加入HINT后的SQL_ID',
    plan_hash_value => 加入HINT后生成的plan_hash_value,
    sql_handle => '旧的执行计划固定后dba_sql_plan_baselines中sql_handle');
    end;
    /

    # 执行
    SQL> begin
    2 :test := dbms_spm.load_plans_from_cursor_cache(
    3 sql_id => 'gw6gd2ggk0h9m',
    4 plan_hash_value => 2614089935,
    5 sql_handle => 'SQL_458606bd5b57f1c3');
    6 end;
    7 /

    PL/SQL procedure successfully completed

    # 查询基线
    SYS@honor1 > select sql_handle, plan_name, origin from dba_sql_plan_baselines;

    SQL_HANDLE PLAN_NAME ORIGIN
    ------------------------------ ------------------------------ --------------
    SQL_458606bd5b57f1c3 SQL_PLAN_4b1h6rpdpgwf3686e388b MANUAL-LOAD
    SQL_458606bd5b57f1c3 SQL_PLAN_4b1h6rpdpgwf36b969528 MANUAL-LOAD


    4.删除最开始固定的旧基线,使新的执行计划的新基线生效
    SQL> var test number;
    SQL> begin
    2 :test := dbms_spm.drop_sql_plan_baseline(sql_handle=>'SQL_458606bd5b57f1c3', plan_name=>'SQL_PLAN_4b1h6rpdpgwf36b969528');
    3 end;
    4 /

    PL/SQL procedure successfully completed

    # 查询基线

    SYS@honor1 > select sql_handle, plan_name, origin from dba_sql_plan_baselines;

    SQL_HANDLE PLAN_NAME ORIGIN
    ------------------------------ ------------------------------ --------------
    SQL_458606bd5b57f1c3 SQL_PLAN_4b1h6rpdpgwf3686e388b MANUAL-LOAD


    5.测试新基线
    HR@honor1 > explain plan for select count(planid) from fundinfo where planid < 99000014000800382760;

    Explained.

    HR@honor1 > select * from table(dbms_xplan.display);

    PLAN_TABLE_OUTPUT
    ------------------------------------------------------------------------------------------------------------------------
    Plan hash value: 2614089935

    ------------------------------------------------------------------------------------
    | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
    ------------------------------------------------------------------------------------
    | 0 | SELECT STATEMENT | | 1 | 22 | 27 (4)| 00:00:01 |
    | 1 | SORT AGGREGATE | | 1 | 22 | | |
    |* 2 | INDEX FULL SCAN| FUNDINFO_PLANID | 18023 | 387K| 27 (4)| 00:00:01 |
    ------------------------------------------------------------------------------------

    Predicate Information (identified by operation id):
    ---------------------------------------------------

    2 - filter(TO_NUMBER("PLANID")<99000014000800382760)

    Note
    -----
    - SQL plan baseline "SQL_PLAN_4b1h6rpdpgwf3686e388b" used for this statement

    18 rows selected.

    # 可以看到走了索引全扫描,新基线已经生效。


    6.删除基线
    SYS@honor1 > select sql_handle, plan_name, origin from dba_sql_plan_baselines;

    SQL_HANDLE PLAN_NAME ORIGIN
    ------------------------------ ------------------------------ --------------
    SQL_458606bd5b57f1c3 SQL_PLAN_4b1h6rpdpgwf37d78711b AUTO-CAPTURE

    var test number;
    begin
    :test := dbms_spm.drop_sql_plan_baseline(sql_handle=>'SQL_458606bd5b57f1c3', plan_name=>'SQL_PLAN_4b1h6rpdpgwf37d78711b');
    end;
    /

    PL/SQL procedure successfully completed.

    SYS@honor1 > select sql_handle, plan_name, origin from dba_sql_plan_baselines;

    no rows selected


    参考文档:
    https://www.cnblogs.com/ddzj01/p/11377049.html

    ------------恢复内容结束------------

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  • 原文地址:https://www.cnblogs.com/chendian0/p/12951287.html
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