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oracle中一个表update慢的优化

2017-09-01 14:13 260 查看

案例简述

数据库：10.129.130.179

用户：tlstat_newbg_studio

语句：

update  DY_USER_ANALYSIS_LEVEL set LOGON_CNT_GUID = LOGON_CNT_GUID + to_number(0) where STAT_TIME = to_date('2016-07-09','yyyy-mm-dd') and game_type='tlbb' and ROLE_LEVEL=3 and DJ_GROUP_TYPE=1 and GROUP_ID=to_number(-1)

这个语句执行的很慢，不走索引。

另一个用户下面的这个表走索引：tlstat_newbg.DY_USER_ANALYSIS_LEVEL

分析

1、把SQL语句改写一下：

select  LOGON_CNT_GUID from  DY_USER_ANALYSIS_LEVEL  where STAT_TIME = to_date('2016-07-09','yyyy-mm-dd') and game_type='tlbb' and ROLE_LEVEL=3 and DJ_GROUP_TYPE=1 and GROUP_ID=to_number(-1)

2、查看这个表上面的索引两个都是可用的

SQL> select TABLE_OWNER,INDEX_NAME,STATUS from dba_indexes where TABLE_NAME='DY_USER_ANALYSIS_LEVEL';

TABLE_OWNER           INDEX_NAME           STATUS

------------------------------ ------------------------------ --------

TLSTAT_NEWBG          SYS_C00106565          VALID

TLSTAT_NEWBG          IND_USER_LEVLE_DD_DATE_GAME   VALID

TLSTAT_NEWBG_STUDIO       IND_USER_LEVLE_DD_DATE_GAME   VALID

TLSTAT_NEWBG_STUDIO       SYS_C00145980          VALID

3、查看索引所在的列，可以看到的在where条件这两列上面有索引，而且stat_time 这一列是前导列

SQL> select COLUMN_NAME,COLUMN_POSITION from dba_ind_columns where INDEX_NAME='IND_USER_LEVLE_DD_DATE_GAME' and TABLE_OWNER='TLSTAT_NEWBG_STUDIO';

COLUMN_NAME

--------------------------------------------------------------------------------

COLUMN_POSITION

---------------

STAT_TIME

GAME_TYPE

PS：选择性比较好的应该做为前导列
4、执行计划的查看（trace的方法会执行，explain plan for不会执行），可以看到全表扫描，后来做的实验现象是---除了当where条件都是这两列并select的语句是这两列其中的一列的时候才会走索引，别的时候不会走索引。（相当于索引失效）
PS：不要用update语句去测试下面的不要模仿

SQL> explain plan for update  DY_USER_ANALYSIS_LEVEL_TEST set LOGON_CNT_GUID = LOGON_CNT_GUID + to_number(0) where STAT_TIME = to_date('2016-07-09','yyyy-mm-dd') and game_type='tlbb' and ROLE_LEVEL=3 and DJ_GROUP_TYPE=1 and GROUP_ID=to_number(-1)

SQL> select * from table(dbms_xplan.display);

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

Plan hash value: 3783326914

--------------------------------------------------------------------------------

-------------

| Id  | Operation      | Name          | Rows  | Bytes | Cost (%CPU

)| Time   |

--------------------------------------------------------------------------------

-------------

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

| 0 | UPDATE STATEMENT  |             |  1 |  26 | 593  (2

)| 00:00:08 |

| 1 | UPDATE       | DY_USER_ANALYSIS_LEVEL |    |    |

|      |

|* 2 | TABLE ACCESS FULL| DY_USER_ANALYSIS_LEVEL |  1 |  26 | 593  (2

)| 00:00:08 |

--------------------------------------------------------------------------------

-------------

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

Predicate Information (identified by operation id):

---------------------------------------------------

 2 - filter("ROLE_LEVEL"=3 AND "GROUP_ID"=(-1) AND "STAT_TIME"=TO_DATE('

        2016-07-09 00:00:00', 'syyyy-mm-dd hh24:mi:ss') AND "DJ_GROUP_TYPE

"=1 AND

       "GAME_TYPE"='tlbb')

16 rows selected.

5、这时候我们怀疑是数据分散的太离散，可以去看一下他的集群因子（集群因子和行数比值越小越好，和块数的比值越接近1越好）

[oracle@s2nstatdb dbm_lite]$ sh showcluster_fac.sh tlstat_newbg_studio DY_USER_ANALYSIS_LEVEL

TABLE_NAME          INDEX_NAME          DISTINCT_KEYS CLUSTERING_FACTOR   BLOCKS  NUM_ROWS LAST_ANALYZED

---------------------------- ---------------------------- ------------- ----------------- ---------- ---------- -------------------

DY_USER_ANALYSIS_LEVEL    SYS_C00145980            484895       51717    3898   484895 2017-08-28 11:46:44

DY_USER_ANALYSIS_LEVEL    IND_USER_LEVLE_DD_DATE_GAME       35       54081    3898   493731 2017-08-28 11:46:44

[oracle@s2nstatdb dbm_lite]$ sh showcluster_fac.sh tlstat_newbg DY_USER_ANALYSIS_LEVEL

TABLE_NAME          INDEX_NAME          DISTINCT_KEYS CLUSTERING_FACTOR   BLOCKS  NUM_ROWS LAST_ANALYZED

---------------------------- ---------------------------- ------------- ----------------- ---------- ---------- -------------------

DY_USER_ANALYSIS_LEVEL    IND_USER_LEVLE_DD_DATE_GAME     16281      130726   56506  8162321 2017-08-21 22:01:08

DY_USER_ANALYSIS_LEVEL    SYS_C00106565           7981757       74016   56506  7981757 2017-08-21 22:00:59

我们对这两个表的集群因子作对比

#tlstat_newbg_studio.DY_USER_ANALYSIS_LEVEL

SQL> select 54081/3898 from dual;

54081/3898

----------

13.874038

SQL> select 54081/493731 from dual;

54081/493731

------------

.109535354

#tlstat_newbg.DY_USER_ANALYSIS_LEVEL

SQL> select 130726/56506 from dual;

130726/56506

------------

 2.31348883

SQL> select 130726/8162321 from dual;

130726/8162321

--------------

   .016015788

看出来不走索引表的集群因子和块的比值明显大于1，列的无序性很明显
PS:可以查看部分数据，发现不走数据的表上面stat_time分布的很奇怪一阵26号一阵30穿插分布。

解决

定制解决方案：将表重建，将列按序排列，这种解决方式基于表数据不大（线上操作不会产生太大的IO消耗），并且和使用这个表的人提前告知一下。
1、查看表是否有依赖关系（REFERENCED_NAME写table name（被关联的那个表），name写tablename（作为主动去关联别人的表））

下面的结果可以看出，连接关系和本案例的用户无关

SQL> desc dba_dependencies

Name                   Null?  Type

----------------------------------------- -------- ----------------------------

OWNER                   NOT NULL VARCHAR2(30)

NAME                   NOT NULL VARCHAR2(30)

TYPE                        VARCHAR2(17)

REFERENCED_OWNER                  VARCHAR2(30)

REFERENCED_NAME                   VARCHAR2(64)

REFERENCED_TYPE                   VARCHAR2(17)

REFERENCED_LINK_NAME                VARCHAR2(128)

DEPENDENCY_TYPE                   VARCHAR2(4)

SQL> select  OWNER,name,type,REFERENCED_TYPE,REFERENCED_OWNER,DEPENDENCY_TYPE from dba_dependencies where REFERENCED_NAME='DY_USER_ANALYSIS_LEVEL';

OWNER              NAME              TYPE

------------------------------ ------------------------------ -----------------

REFERENCED_TYPE  REFERENCED_OWNER        DEPE

----------------- ------------------------------ ----

TLSTAT_NEWFG          DY_USER_ANALYSIS_LEVEL     SYNONYM

TABLE       TLSTAT_NEWBG          HARD

SQL> select  OWNER,name,type,REFERENCED_TYPE,REFERENCED_OWNER,DEPENDENCY_TYPE from dba_dependencies where name='DY_USER_ANALYSIS_LEVEL';

OWNER              NAME              TYPE

------------------------------ ------------------------------ -----------------

REFERENCED_TYPE  REFERENCED_OWNER        DEPE

----------------- ------------------------------ ----

TLSTAT_NEWFG          DY_USER_ANALYSIS_LEVEL     SYNONYM

TABLE       TLSTAT_NEWBG          HARD

2、查看表空间是否够用，我们希望规范的将表的数据空间放在TLBB_DATA中，索引放在TLBB_INDEX中
a.查看用户允许除了默认使用的表空间可以使用的表空间,空的。

SQL> select TABLESPACE_NAME from dba_ts_quotas where USERNAME=UPPER('tlstat_newbg_studio');

TABLESPACE_NAME

------------------------------

TLBB_DATA

TLBB_INDEX

b.查看用户默认使用的表空间

SQL> select DEFAULT_TABLESPACE from dba_users where USERNAME=UPPER('TLSTAT_NEWBG_STUDIO');

DEFAULT_TABLESPACE

------------------------------

USERS

c.授权使用表空间

SQL> alter user TLSTAT_NEWBG_STODIO quota unlimited on TLBB_INDEX;

SQL> alter user TLSTAT_NEWBG_STODIO quota unlimited on TLBB_DATA;

SQL> select TABLESPACE_NAME from dba_ts_quotas where USERNAME=UPPER('tlstat_newbg_studio');

TABLESPACE_NAME

------------------------------

TLBB_DATA

TLBB_INDEX

d.查看表空间使用，表空间是自动扩张的，现在已经用的和最大使用空间，BYTES会比MAXBYTES大的原因是有两个非扩张的大小的表空间文件。空间大小这么看是没有问题的

SQL> select SUM(BYTES)/(1024*1024),SUM(MAXBYTES)/(1024*1024) from dba_data_files where TABLESPACE_NAME='TLBB_INDEX';

SUM(BYTES)/(1024*1024) SUM(MAXBYTES)/(1024*1024)

---------------------- -------------------------

         8420        65534.9844

SQL> select AUTOEXTENSIBLE from dba_data_files where TABLESPACE_NAME='TLBB_INDEX';

AUT

---

YES

YES

SQL> select SUM(BYTES)/(1024*1024),SUM(MAXBYTES)/(1024*1024) from dba_data_files where TABLESPACE_NAME='TLBB_DATA';

SUM(BYTES)/(1024*1024) SUM(MAXBYTES)/(1024*1024)

---------------------- -------------------------

      208568.984        162812.984

SQL> select BYTES,MAXBYTES,AUTOEXTENSIBLE from dba_data_files where TABLESPACE_NAME='TLBB_DATA';

   BYTES  MAXBYTES AUT

---------- ---------- ---

3.4360E+10 3.4360E+10 YES

3.4359E+10 3.4359E+10 YES

3.4359E+10 3.4359E+10 YES

3.4359E+10 3.4359E+10 YES

3.2212E+10     0 NO

3.2212E+10     0 NO

1.6840E+10 3.3286E+10 YES

7 rows selected.

3、查看建表和建索引语句

SQL> set line 200

SQL> set pagesize 0

SQL> set long 99999

SQL> select dbms_metadata.get_ddl('TABLE','DY_USER_ANALYSIS_LEVEL','TLSTAT_NEWBG_STUDIO') from dual;

 CREATE TABLE "TLSTAT_NEWBG_STUDIO"."DY_USER_ANALYSIS_LEVEL"

  (  "ID" NUMBER(11,0) NOT NULL ENABLE,

    "STAT_TIME" DATE,

    "GAME_TYPE" VARCHAR2(50),

    "ZONE_ID" NUMBER DEFAULT -1,

    "GROUP_ID" NUMBER DEFAULT -1,

    "ROLE_LEVEL" NUMBER DEFAULT 0,

    "DJ_GROUP_TYPE" NUMBER DEFAULT 0,

    "CONSUME_CNT" NUMBER DEFAULT 0,

    "CONSUME_LOST_CNT" NUMBER DEFAULT 0,

    "LOGON_CNT" NUMBER DEFAULT 0,

    "LOGON_LOST_CNT" NUMBER DEFAULT 0,

    "CONSUME_AMOUNT" NUMBER DEFAULT 0,

    "LOGON_CNT_GUID" NUMBER DEFAULT 0,

     PRIMARY KEY ("ID")

USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS

STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645

PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)

TABLESPACE "USERS"  ENABLE

  ) PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS NOLOGGING

STORAGE(INITIAL 16384 NEXT 8192 MINEXTENTS 1 MAXEXTENTS 2147483645

PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)

TABLESPACE "USERS"

4、DDL语句改写

a.建表

CREATE TABLE "TLSTAT_NEWBG_STUDIO"."DY_USER_ANALYSIS_LEVEL_REBUILD"

  (  "ID" NUMBER(11,0) NOT NULL ENABLE,

    "STAT_TIME" DATE,

    "GAME_TYPE" VARCHAR2(50),

    "ZONE_ID" NUMBER DEFAULT -1,

    "GROUP_ID" NUMBER DEFAULT -1,

    "ROLE_LEVEL" NUMBER DEFAULT 0,

    "DJ_GROUP_TYPE" NUMBER DEFAULT 0,

    "CONSUME_CNT" NUMBER DEFAULT 0,

    "CONSUME_LOST_CNT" NUMBER DEFAULT 0,

    "LOGON_CNT" NUMBER DEFAULT 0,

    "LOGON_LOST_CNT" NUMBER DEFAULT 0,

    "CONSUME_AMOUNT" NUMBER DEFAULT 0,

    "LOGON_CNT_GUID" NUMBER DEFAULT 0

TABLESPACE "TLBB_DATA"

b.建主键

 CREATE UNIQUE INDEX "TLSTAT_NEWBG_STUDIO"."PK_DY_USER_ANALYSIS_LEVEL" ON "TLSTAT_NEWBG_STUDIO"."DY_USER_ANALYSIS_LEVEL_REBUILD" ("ID")

PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS

STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645

PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)

TABLESPACE "USERS"

 alter table TLSTAT_NEWBG_STUDIO.DY_USER_ANALYSIS_LEVEL_REBUILD add constraint PK_DY_USER_ANALYSIS_LEVEL primary key(ID) using index tablespace TLBB_INDEX;

c.建索引

CREATE INDEX TLSTAT_NEWBG_STUDIO.IND_USER_LEVLE_DD_DATE_GAME_RE on TLSTAT_NEWBG_STUDIO.DY_USER_ANALYSIS_LEVEL_REBUILD(STAT_TIME,GAME_TYPE) TABLESPACE TLBB_INDEX;

d.插入数据

SQL> insert into TLSTAT_NEWBG_STUDIO.DY_USER_ANALYSIS_LEVEL_REBUILD select * from TLSTAT_NEWBG_STUDIO.DY_USER_ANALYSIS_LEVEL order by stat_time,game_type;

SQL〉COMMIT;

e.将原来的表改名

alter table TLSTAT_NEWBG_STUDIO.DY_USER_ANALYSIS_LEVEL rename to DY_USER_ANALYSIS_LEVEL_OLD

f.将新表改名

alter table TLSTAT_NEWBG_STUDIO.DY_USER_ANALYSIS_LEVEL_REBUILD rename to DY_USER_ANALYSIS_LEVEL

校验

1、收集一下统计信息

exec DBMS_STATS.GATHER_TABLE_STATS(ownname=>'TLSTAT_NEWBG_STUDIO',tabname=>'DY_USER_ANALYSIS_LEVEL');

2、查看一下集群因子是否降下来了，可以看出来已经很大的降低了

[oracle@s2nstatdb dbm_lite]$ sh showcluster_fac.sh TLSTAT_NEWBG_STUDIO DY_USER_ANALYSIS_LEVEL

TABLE_NAME          INDEX_NAME          DISTINCT_KEYS CLUSTERING_FACTOR   BLOCKS  NUM_ROWS LAST_ANALYZED

---------------------------- ---------------------------- ------------- ----------------- ---------- ---------- -------------------

DY_USER_ANALYSIS_LEVEL    IND_USER_LEVLE_DD_DATE_GAME_      35       3723    3772   493731 2017-08-30 16:07:04

RE

DY_USER_ANALYSIS_LEVEL    PK_DY_USER_ANALYSIS_LEVEL      493731      114430    3772   493731 2017-08-30 16:07:03

3、再看一下执行计划是否走索引

SQL> explain plan for select  LOGON_CNT_GUID from  DY_USER_ANALYSIS_LEVEL where STAT_TIME = to_date('2016-07-09','yyyy-mm-dd') and game_type='tlbb' and ROLE_LEVEL=3 and DJ_GROUP_TYPE=1 and GROUP_ID=to_number(-1);

Explained.

SQL> select * from table(dbms_xplan.display);

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

Plan hash value: 2737695412

--------------------------------------------------------------------------------

------------------------------

| Id  | Operation          | Name              | Rows  | B

ytes | Cost (%CPU)| Time   |

--------------------------------------------------------------------------------

------------------------------

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

|  0 | SELECT STATEMENT       |                 |   1 |

 88 |  74  (0)| 00:00:01 |

|* 1 | TABLE ACCESS BY INDEX ROWID| DY_USER_ANALYSIS_LEVEL     |   1 |

 88 |  74  (0)| 00:00:01 |

|* 2 |  INDEX RANGE SCAN      | IND_USER_LEVLE_DD_DATE_GAME_RE | 8143 |

   |  56  (0)| 00:00:01 |

--------------------------------------------------------------------------------

------------------------------

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

Predicate Information (identified by operation id):

---------------------------------------------------

  1 - filter("ROLE_LEVEL"=3 AND "DJ_GROUP_TYPE"=1 AND "GROUP_ID"=(-1))

  2 - access("STAT_TIME"=TO_DATE(' 2016-07-09 00:00:00', 'syyyy-mm-dd hh24:mi:s

s') AND

       "GAME_TYPE"='tlbb')

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------

Note

-----

  - dynamic sampling used for this statement

20 rows selected.

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