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[20240325]expand_sql_text dba_hist_sysstat(12c).txt

时间：2024-03-26 21:23:23浏览次数：29  
标签：00 12c dba text STAT A4 DBID SEL ID

[20240325]expand_sql_text dba_hist_sysstat(12c).txt

--//前几天测试dba_hist_sysdate的底层视图定义里面包含提示.
--//测试一条sql语句包含dba_hist_sysstat 使用expand_sql_text的展开情况.

1.环境:
SYS@test> @ver1
PORT_STRING                    VERSION        BANNER                                                                               CON_ID
------------------------------ -------------- -------------------------------------------------------------------------------- ----------
IBMPC/WIN_NT64-9.1.0           12.2.0.1.0     Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production              0

2.测试:
SYS@test> @ v2 dba_hist_sysstat
Show SQL text of views matching "dba_hist_sysstat"...
V_OWNER VIEW_NAME        TEXT
------- ---------------- ------------------------------------------------------------------------------------------------
SYS     DBA_HIST_SYSSTAT select "SNAP_ID","DBID","INSTANCE_NUMBER","STAT_ID","STAT_NAME","VALUE","CON_DBID","CON_ID" from
                         AWR_ROOT_SYSSTAT

SYS@test> @ v2 AWR_ROOT_SYSSTAT
Show SQL text of views matching "AWR_ROOT_SYSSTAT"...
V_OWNER VIEW_NAME        TEXT
------- ---------------- ------------------------------------------------------------------------------------------------
SYS     AWR_ROOT_SYSSTAT select /*+ leading(sn s nm) use_hash(sn s) */
                         s.snap_id, s.dbid, s.instance_number,
                         s.stat_id, nm.stat_name, value,
                         decode(s.con_dbid, 0, s.dbid, s.con_dbid),
                         con_dbid_to_id(decode(s.con_dbid, 0, s.dbid, s.con_dbid)) con_id
                         from WRM$_SNAPSHOT sn, WRH$_SYSSTAT s, WRH$_STAT_NAME nm
                         where      s.stat_id          = nm.stat_id
                         and  s.dbid             = nm.dbid
                         and  s.snap_id          = sn.snap_id
                         and  s.dbid             = sn.dbid
                         and  s.instance_number  = sn.instance_number
                         and  sn.status = 0
--//底层视图AWR_ROOT_SYSSTAT包含提示leading(sn s nm) use_hash(sn s)

SYS@test> select max(snap_id),max(dbid) from dba_hist_snapshot;
MAX(SNAP_ID)  MAX(DBID)
------------ ----------
         588 2286984624

SYS@test> SELECT stat_name,value FROM dba_hist_sysstat WHERE snap_id = 588 AND instance_number = 1 AND dbid  = 2286984624 AND stat_name in ('sorts (rows)');
STAT_NAME                 VALUE
-------------------- ----------
sorts (rows)             764924

SYS@test> @ hash
HASH_VALUE SQL_ID        CHILD_NUMBER KGL_BUCKET PLAN_HASH_VALUE HASH_HEX   SQL_EXEC_START      SQL_EXEC_ID
---------- ------------- ------------ ---------- --------------- ---------- ------------------- -----------
3920320955 3bkv493nuqqdv            1      88507      2701875554  e9ab59bb  2024-03-24 20:59:21    16777217

SYS@test> @ expand_sql_text.sql 3bkv493nuqqdv
SELECT "A1"."STAT_NAME" "STAT_NAME","A1"."VALUE" "VALUE" FROM  (SELECT "A2"."SNAP_ID" "SNAP_ID","A2"."DBID" "DBID","A2"."INSTANCE_NUMBER" "INSTANCE_NUMBER","A2"."STAT_NAME" "STAT_NAME","A2"."VALUE" "VALUE" FROM  (SELECT /*+ LEADING ("A5" "A4" "A3") USE_HASH ("A4")
USE_HASH ("A5") */ "A4"."SNAP_ID" "SNAP_ID","A4"."DBID" "DBID","A4"."INSTANCE_NUMBER" "INSTANCE_NUMBER","A3"."STAT_NAME" "STAT_NAME","A4"."VALUE" "VALUE",CON_DBID_TO_ID(DECODE("A4"."CON_DBID",0,"A4"."DBID","A4"."CON_DBID")) "CON_ID" FROM "SYS"."WRM$_SNAPSHOT"
"A5","SYS"."WRH$_SYSSTAT" "A4","SYS"."WRH$_STAT_NAME" "A3" WHERE "A4"."STAT_ID"="A3"."STAT_ID" AND "A4"."DBID"="A3"."DBID" AND "A4"."SNAP_ID"="A5"."SNAP_ID" AND "A4"."DBID"="A5"."DBID" AND "A4"."INSTANCE_NUMBER"="A5"."INSTANCE_NUMBER" AND "A5"."STATUS"=0) "A2") "A1"
WHERE "A1"."SNAP_ID"=588 AND "A1"."INSTANCE_NUMBER"=1 AND "A1"."DBID"=2286984624 AND "A1"."STAT_NAME"='sorts (rows)'
PL/SQL procedure successfully completed.

--//格式化如下:

SELECT "A1"."STAT_NAME" "STAT_NAME","A1"."VALUE" "VALUE"
  FROM (SELECT "A2"."SNAP_ID" "SNAP_ID",
       "A2"."DBID" "DBID","A2"."INSTANCE_NUMBER" "INSTANCE_NUMBER",
       "A2"."STAT_NAME" "STAT_NAME",
       "A2"."VALUE" "VALUE" FROM (SELECT /*+ LEADING ("A5" "A4" "A3") USE_HASH ("A4") USE_HASH ("A5") */ "A4"."SNAP_ID" "SNAP_ID",
       "A4"."DBID" "DBID","A4"."INSTANCE_NUMBER" "INSTANCE_NUMBER",
       "A3"."STAT_NAME" "STAT_NAME","A4"."VALUE" "VALUE",
       CON_DBID_TO_ID(DECODE("A4"."CON_DBID",
       0,"A4"."DBID","A4"."CON_DBID")) "CON_ID"
  FROM "SYS"."WRM$_SNAPSHOT" "A5","SYS"."WRH$_SYSSTAT" "A4",
       "SYS"."WRH$_STAT_NAME" "A3"
 WHERE "A4"."STAT_ID"         = "A3"."STAT_ID"
   AND "A4"."DBID"            = "A3"."DBID"
   AND "A4"."SNAP_ID"         = "A5"."SNAP_ID"
   AND "A4"."DBID"            = "A5"."DBID"
   AND "A4"."INSTANCE_NUMBER" = "A5"."INSTANCE_NUMBER"
   AND "A5"."STATUS"          = 0) "A2") "A1"
 WHERE "A1"."SNAP_ID"         = 588
   AND "A1"."INSTANCE_NUMBER" = 1
   AND "A1"."DBID"            = 2286984624
   AND "A1"."STAT_NAME"       = 'sorts (rows)'

--//存在提示LEADING ("A5" "A4" "A3") USE_HASH ("A4") USE_HASH ("A5"),与前面的写法有一些不同.
--//也就是通过这样的方式也可以看出语句里面包含提示.

3.12c下看执行计划没有hint_report功能.
SYS@test> SELECT stat_name,value FROM dba_hist_sysstat WHERE snap_id = 588 AND instance_number = 1 AND dbid  = 2286984624 AND stat_name in ('sorts (rows)');
STAT_NAME                 VALUE
-------------------- ----------
sorts (rows)             764924

SYS@test> @ dpc '' hint_report ''
PLAN_TABLE_OUTPUT
---------------------------------------------------------------------------------------------------------------------------------------------------------
Error: format 'all allstats last peeked_binds cost partition note -projection -outline hint_report' not valid for DBMS_XPLAN.DISPLAY_CURSOR()

--//12c版本执行计划就看不到Hint Report的相关信息.
--//执行计划看到内容如下:

Plan hash value: 1931519367
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| Id  | Operation                                    | Name             | Starts | E-Rows |E-Bytes| Cost (%CPU)| E-Time   | Pstart| Pstop | A-Rows |   A-Time   | Buffers |  OMem |  1Mem | Used-Mem |
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT                             |                  |      1 |        |       |     2 (100)|          |       |       |      1 |00:00:00.01 |    1628 |       |       |          |
|*  1 |  HASH JOIN                                   |                  |      1 |      1 |   126 |     2   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |    1628 |  1448K|  1448K| 1504K (0)|
|*  2 |   HASH JOIN                                  |                  |      1 |      1 |    81 |     1   (0)| 00:00:01 |       |       |   1788 |00:00:00.01 |    1604 |  1572K|  1572K|  713K (0)|
|*  3 |    TABLE ACCESS BY INDEX ROWID               | WRM$_SNAPSHOT    |      1 |      1 |    16 |     1   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |       2 |       |       |          |
|*  4 |     INDEX UNIQUE SCAN                        | WRM$_SNAPSHOT_PK |      1 |      1 |       |     0   (0)|          |       |       |      1 |00:00:00.01 |       1 |       |       |          |
|   5 |    PARTITION RANGE SINGLE                    |                  |      1 |      1 |    65 |     0   (0)|          |     2 |     2 |   1788 |00:00:00.01 |    1602 |       |       |          |
|   6 |     TABLE ACCESS BY LOCAL INDEX ROWID BATCHED| WRH$_SYSSTAT     |      1 |      1 |    65 |     0   (0)|          |     2 |     2 |   1788 |00:00:00.01 |    1602 |       |       |          |
|*  7 |      INDEX RANGE SCAN                        | WRH$_SYSSTAT_PK  |      1 |      1 |       |     0   (0)|          |     2 |     2 |   1788 |00:00:00.01 |      16 |       |       |          |
|*  8 |   TABLE ACCESS FULL                          | WRH$_STAT_NAME   |      1 |      1 |    45 |     1   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |      24 |       |       |          |
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
   1 - SEL$5C160134
   3 - SEL$5C160134 / SN@SEL$3
   4 - SEL$5C160134 / SN@SEL$3
   6 - SEL$5C160134 / S@SEL$3
   7 - SEL$5C160134 / S@SEL$3
   8 - SEL$5C160134 / NM@SEL$3
Outline Data
-------------
 /*+
     BEGIN_OUTLINE_DATA
     FULL(@"SEL$5C160134" "NM"@"SEL$3")
     USE_HASH(@"SEL$5C160134" "NM"@"SEL$3")
     IGNORE_OPTIM_EMBEDDED_HINTS
     OPTIMIZER_FEATURES_ENABLE('12.2.0.1')
     DB_VERSION('12.2.0.1')
     ALL_ROWS
     OUTLINE_LEAF(@"SEL$5C160134")
     MERGE(@"SEL$335DD26A" >"SEL$1")
     OUTLINE(@"SEL$1")
     OUTLINE(@"SEL$335DD26A")
     MERGE(@"SEL$3" >"SEL$2")
     OUTLINE(@"SEL$2")
     OUTLINE(@"SEL$3")
     INDEX_RS_ASC(@"SEL$5C160134" "SN"@"SEL$3" ("WRM$_SNAPSHOT"."DBID" "WRM$_SNAPSHOT"."SNAP_ID" "WRM$_SNAPSHOT"."INSTANCE_NUMBER"))
     INDEX_RS_ASC(@"SEL$5C160134" "S"@"SEL$3" ("WRH$_SYSSTAT"."DBID" "WRH$_SYSSTAT"."SNAP_ID" "WRH$_SYSSTAT"."INSTANCE_NUMBER" "WRH$_SYSSTAT"."STAT_ID" "WRH$_SYSSTAT"."CON_DBID"))
     BATCH_TABLE_ACCESS_BY_ROWID(@"SEL$5C160134" "S"@"SEL$3")
     LEADING(@"SEL$5C160134" "SN"@"SEL$3" "S"@"SEL$3" "NM"@"SEL$3")
     USE_HASH(@"SEL$5C160134" "S"@"SEL$3")
     END_OUTLINE_DATA
 */
Predicate Information (identified by operation id):
---------------------------------------------------

   1 - access("S"."STAT_ID"="NM"."STAT_ID" AND "S"."DBID"="NM"."DBID")
   2 - access("S"."SNAP_ID"="SN"."SNAP_ID" AND "S"."DBID"="SN"."DBID" AND "S"."INSTANCE_NUMBER"="SN"."INSTANCE_NUMBER")
   3 - filter("SN"."STATUS"=0)
   4 - access("SN"."DBID"=2286984624 AND "SN"."SNAP_ID"=588 AND "SN"."INSTANCE_NUMBER"=1)
   7 - access("S"."DBID"=2286984624 AND "S"."SNAP_ID"=588 AND "S"."INSTANCE_NUMBER"=1)
   8 - filter(("NM"."STAT_NAME"='sorts (rows)' AND "NM"."DBID"=2286984624))

Note
-----
   - this is an adaptive plan
--//SN@SEL$3 =>WRM$_SNAPSHOT
--//S@SEL$3  =>WRH$_SYSSTAT
--//NM@SEL$3 =>WRH$_STAT_NAME

--//执行计划比较好的连接顺序是
LEADING(@"SEL$5C160134" "SN"@"SEL$3" "NM"@"SEL$3" "S"@"SEL$3" )

--//看到执行计划如下:
Plan hash value: 529202186
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| Id  | Operation                      | Name             | Starts | E-Rows |E-Bytes| Cost (%CPU)| E-Time   | Pstart| Pstop | A-Rows |   A-Time   | Buffers |  OMem |  1Mem | Used-Mem |
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT               |                  |      1 |        |       |    15 (100)|          |       |       |      1 |00:00:00.03 |      49 |       |       |          |
|*  1 |  HASH JOIN                     |                  |      1 |      1 |    85 |    15   (0)| 00:00:01 |       |       |      1 |00:00:00.03 |      49 |  1082K|  1082K|  406K (0)|
|   2 |   PART JOIN FILTER CREATE      | :BF0000          |      1 |      1 |    61 |     8   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |      25 |       |       |          |
|   3 |    NESTED LOOPS                |                  |      1 |      1 |    61 |     8   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |      25 |       |       |          |
|*  4 |     TABLE ACCESS BY INDEX ROWID| WRM$_SNAPSHOT    |      1 |      1 |    16 |     1   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |       2 |       |       |          |
|*  5 |      INDEX UNIQUE SCAN         | WRM$_SNAPSHOT_PK |      1 |      1 |       |     0   (0)|          |       |       |      1 |00:00:00.01 |       1 |       |       |          |
|*  6 |     TABLE ACCESS FULL          | WRH$_STAT_NAME   |      1 |      1 |    45 |     7   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |      23 |       |       |          |
|   7 |   PARTITION RANGE SINGLE       |                  |      1 |   1788 | 42912 |     7   (0)| 00:00:01 |KEY(AP)|KEY(AP)|   1788 |00:00:00.03 |      24 |       |       |          |
|*  8 |    TABLE ACCESS FULL           | WRH$_SYSSTAT     |      1 |   1788 | 42912 |     7   (0)| 00:00:01 |     2 |     2 |   1788 |00:00:00.01 |      24 |       |       |          |
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------

   1 - SEL$5C160134
   4 - SEL$5C160134 / SN@SEL$3
   5 - SEL$5C160134 / SN@SEL$3
   6 - SEL$5C160134 / NM@SEL$3
   8 - SEL$5C160134 / S@SEL$3

Outline Data
-------------

  /*+
      BEGIN_OUTLINE_DATA
      IGNORE_OPTIM_EMBEDDED_HINTS
      OPTIMIZER_FEATURES_ENABLE('12.2.0.1')
      DB_VERSION('12.2.0.1')
      ALL_ROWS
      OUTLINE_LEAF(@"SEL$5C160134")
      MERGE(@"SEL$335DD26A" >"SEL$1")
      OUTLINE(@"SEL$1")
      OUTLINE(@"SEL$335DD26A")
      MERGE(@"SEL$3" >"SEL$2")
      OUTLINE(@"SEL$2")
      OUTLINE(@"SEL$3")
      INDEX_RS_ASC(@"SEL$5C160134" "SN"@"SEL$3" ("WRM$_SNAPSHOT"."DBID" "WRM$_SNAPSHOT"."SNAP_ID" "WRM$_SNAPSHOT"."INSTANCE_NUMBER"))
      FULL(@"SEL$5C160134" "NM"@"SEL$3")
      FULL(@"SEL$5C160134" "S"@"SEL$3")
      LEADING(@"SEL$5C160134" "SN"@"SEL$3" "NM"@"SEL$3" "S"@"SEL$3")
      USE_NL(@"SEL$5C160134" "NM"@"SEL$3")
      USE_HASH(@"SEL$5C160134" "S"@"SEL$3")
      END_OUTLINE_DATA
  */

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

   1 - access("S"."DBID"="NM"."DBID" AND "S"."SNAP_ID"="SN"."SNAP_ID" AND "S"."STAT_ID"="NM"."STAT_ID" AND "S"."DBID"="SN"."DBID" AND
              "S"."INSTANCE_NUMBER"="SN"."INSTANCE_NUMBER")
   4 - filter("SN"."STATUS"=0)
   5 - access("SN"."DBID"=2286984624 AND "SN"."SNAP_ID"=588 AND "SN"."INSTANCE_NUMBER"=1)
   6 - filter(("NM"."STAT_NAME"='sorts (rows)' AND "NM"."DBID"=2286984624))
   8 - filter(("S"."SNAP_ID"=588 AND "S"."INSTANCE_NUMBER"=1 AND "S"."DBID"=2286984624))
68 rows selected.

--//实际上id=8,不用全表扫描,因为前面WRH$_STAT_NAME已经知道stat_id,这样仅仅通过索引主键就可以定位.
index(@"SEL$5C160134" "S"@"SEL$3")
LEADING(@"SEL$5C160134" "SN"@"SEL$3" "NM"@"SEL$3" "S"@"SEL$3" )
USE_nl(@"SEL$5C160134" "S"@"SEL$3")

--//加入以上提示执行计划如下,这才是最佳的执行计划,上个星期思路太乱了,实际上仅仅涉及3个表,很容易通过提示获得最佳的执行计
--//划.
Plan hash value: 340881634
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
| Id  | Operation                          | Name             | Starts | E-Rows |E-Bytes| Cost (%CPU)| E-Time   | Pstart| Pstop | A-Rows |   A-Time   | Buffers |
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT                   |                  |      1 |        |       |    10 (100)|          |       |       |      1 |00:00:00.01 |      30 |
|   1 |  NESTED LOOPS                      |                  |      1 |      1 |    85 |    10   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |      30 |
|   2 |   NESTED LOOPS                     |                  |      1 |      1 |    85 |    10   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |      29 |
|   3 |    NESTED LOOPS                    |                  |      1 |      1 |    61 |     8   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |      26 |
|*  4 |     TABLE ACCESS BY INDEX ROWID    | WRM$_SNAPSHOT    |      1 |      1 |    16 |     1   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |       2 |
|*  5 |      INDEX UNIQUE SCAN             | WRM$_SNAPSHOT_PK |      1 |      1 |       |     0   (0)|          |       |       |      1 |00:00:00.01 |       1 |
|*  6 |     TABLE ACCESS FULL              | WRH$_STAT_NAME   |      1 |      1 |    45 |     7   (0)| 00:00:01 |       |       |      1 |00:00:00.01 |      24 |
|   7 |    PARTITION RANGE SINGLE          |                  |      1 |      1 |       |     1   (0)| 00:00:01 |     2 |     2 |      1 |00:00:00.01 |       3 |
|*  8 |     INDEX RANGE SCAN               | WRH$_SYSSTAT_PK  |      1 |      1 |       |     1   (0)| 00:00:01 |     2 |     2 |      1 |00:00:00.01 |       3 |
|   9 |   TABLE ACCESS BY LOCAL INDEX ROWID| WRH$_SYSSTAT     |      1 |      1 |    24 |     2   (0)| 00:00:01 |     2 |     2 |      1 |00:00:00.01 |       1 |
-----------------------------------------------------------------------------------------------------------------------------------------------------------------

--//实际上如果早知道oracle在底层视图写死提示,问题很容易解决.可以简单的加入
IGNORE_OPTIM_EMBEDDED_HINTS

--//很奇怪使用这个提示不行 OPT_PARAM('_optimizer_ignore_hints','true').
SYS@test> alter session set "_optimizer_ignore_hints"=true;
Session altered.

--//12c下这个参数还是隐含参数,19c已经不是了.

4.附上expand_sql_text.sql代码:
set long 20000
set serveroutput on
declare
    L_sqltext clob := null;
    l_version varchar2(3) := null;
    l_sql     clob := null;
    l_result  clob := null;
begin
    select regexp_replace(version,'\..*') into l_version from v$instance;
    select sql_fulltext into l_sqltext from v$sqlarea where sql_id='&&1';

    if l_version = '11' then
       l_sql := 'begin
                   dbms_sql2.expand_sql_text( :a,:b );
                 end;';

    elsif l_version >= '12' then

      l_sql := 'begin
                  dbms_utility.expand_sql_text(:a,:b);
                end;';
    end if;
    execute immediate l_sql using in l_sqltext,out l_result;
    dbms_output.put_line(l_result);
end;
/
set serveroutput off

标签：00,12c,dba,text,STAT,A4,DBID,SEL,ID
From： https://www.cnblogs.com/lfree/p/18097605

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