第十二章： 表(1)

1、表的功能：存儲、管理數據的基本單元(二維表：有行和列組成)

2、表的類型：

1)普通表：heap table ：數據存儲時，無序的，對它的訪問采用全表掃描。

2)分區表：(>2G)對大表進行優化?? (Range Partitioning，List PartitioningHash Partitioning，Composite Partitioning)

---------按range 建立分區表

10:50:38 SQL> CREATE TABLE sales_range

(salesman_id? NUMBER(5),

salesman_name VARCHAR2(30),

sales_amount? NUMBER(10),

sales_date??? DATE)

PARTITION BY RANGE(sales_date)

10:51:11?? 7? (

10:51:11?? 8? lespace user01,

PARTITION sales_jan2000 VALUES LESS THAN(TO_DATE('04/01/2011','MM/DD/YYYY')) tablespace user01,

PARTITION sales_feb2000 VALUES LESS THAN(TO_DATE('07/01/2011','MM/DD/YYYY')) tablespace user02,

PARTITION sales_mar2000 VALUES LESS THAN(TO_DATE('10/01/2011','MM/DD/YYYY'))? tablespace user03,

PARTITION sales_apr2000 VALUES LESS THAN(TO_DATE('01/01/2012','MM/DD/YYYY'))? tablespace user04

10:51:11? 12? );

Table created.

10:51:12 SQL>

10:55:19 SQL> insert into? sales_range? values ( 1001,'tom',1000,'2011-02-01');

1 row created.

10:55:34 SQL> insert into? sales_range? values ( 1002,'jerry',1000,'2011-05-01');

1 row created.

10:55:43 SQL> insert into? sales_range? values ( 1003,'rose',1000,'2011-08-01');

1 row created.

10:55:55 SQL> insert into? sales_range? values ( 1004,'john',1000,'2011-01-01');

1 row created.

10:56:04 SQL> select * from sales_range partition (sales_jan2000);

SALESMAN_ID SALESMAN_NAME????????????????? SALES_AMOUNT SALES_DATE

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

1001 tom??????????????????????????????????? 1000 2011-02-01 00:00:00

1004 john?????????????????????????????????? 1000 2011-01-01 00:00:00

10:56:09 SQL> insert into? sales_range? values ( 1005,'john',1000,'2011-11-01');

1 row created.

10:56:34 SQL> select * from sales_range partition (sales_jan2000);

SALESMAN_ID SALESMAN_NAME????????????????? SALES_AMOUNT SALES_DATE

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

1001 tom??????????????????????????????????? 1000 2011-02-01 00:00:00

1004 john?????????????????????????????????? 1000 2011-01-01 00:00:00

10:56:36 SQL> select * from sales_range partition (sales_feb2000);

SALESMAN_ID SALESMAN_NAME????????????????? SALES_AMOUNT SALES_DATE

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

1002 jerry????????????????????????????????? 1000 2011-05-01 00:00:00

10:56:40 SQL> select * from sales_range partition (sales_mar2000);

SALESMAN_ID SALESMAN_NAME????????????????? SALES_AMOUNT SALES_DATE

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

1003 rose?????????????????????????????????? 1000 2011-08-01 00:00:00

10:56:47 SQL> select * from sales_range partition (sales_apr2000);

SALESMAN_ID SALESMAN_NAME????????????????? SALES_AMOUNT SALES_DATE

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

1005 john?????????????????????????????????? 1000 2011-11-01 00:00:00

10:56:52 SQL> select * from sales_range ;

SALESMAN_ID SALESMAN_NAME????????????????? SALES_AMOUNT SALES_DATE

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

1001 tom??????????????????????????????????? 1000 2011-02-01 00:00:00

1004 john?????????????????????????????????? 1000 2011-01-01 00:00:00

1002 jerry????????????????????????????????? 1000 2011-05-01 00:00:00

1003 rose?????????????????????????????????? 1000 2011-08-01 00:00:00

1005 john?????????????????????????????????? 1000 2011-11-01 00:00:00

10:57:08 SQL>

3)索引組織表(IOT)(如果表經常以主鍵為索引查詢，可建立索引組織表，加快表的訪問速度)

建立索引組織表

04:33:59 SQL> create table sales_info(

04:34:11?? 2? onstraid number(6)? primary key,

04:34:55?? 3? customer_name varchar2(30) ,slaes_amount number(10,2),

04:35:26?? 4? sales_date date,remark varchar2(2000)

04:35:56?? 5? ) organization index tablespace users01

04:36:28?? 6? pctthreshold 20 including remark

04:36:46?? 7? overflow tablespace users02;

Table created.

定義索引表時，主鍵約束和ORGANIZATION? index 選項必須指定。

PCTTHRESHOLD :用于指定數據塊中為鍵列和部分非鍵列數據所預留空間的百分比；如果數據塊剩余空間低于PCTTHRESHOLD 設置，Oracle會將其他數據存放到溢出段。

INCLUDING column ：用于指定數據被存放到溢出段的起始列。

OVERFLOW TABLESPACE：用于指定溢出段所在的表空間。

4)簇：cluster (多表鏈接查詢)

1)建立簇

09:31:25 SQL> create cluster dept_emp_clu (deptno number(3))

09:33:19?? 2? pctfree 20 pctused 60

09:33:31?? 3? size 500 tablespace users01;

Cluster created.

2)建立簇表

09:33:56 SQL> create table department(

09:34:21?? 2? id number(3) primary key,

09:34:40?? 3? dname varchar(2) ,loc varchar2(13))

09:35:07?? 4? cluster dept_emp_clu(id);

Table created.

09:35:24 SQL> create table employee(

09:36:00?? 2? eno number(4) primary key ,

09:36:21?? 3? ename varchar2(10),

09:36:34?? 4? job varchar2(9),

09:36:50?? 5? mgr number(4),

09:36:59?? 6? hiredate date,

09:37:05?? 7? sal number(7,2),

09:37:14?? 8? comm number(7,2),

09:37:26?? 9? dept_id number(3) references department

09:38:09? 10? ) cluster dept_emp_clu(dept_id);

Table created.

3)建立索引

09:38:31 SQL> create index dept_emp_idx on cluster dept_emp_clu

09:39:12?? 2?? tablespace users02;

Index created.

----------------cluster訪問和普通表連接查詢訪問 對比

22:27:03 SQL> select e.eno,e.ename,e.sal,d.id,d.dname,d.loc from employee e,department d

22:27:08?? 2?? where e.dept_id=d.id;

ENO ENAME???????????? SAL???????? ID DNAME??????????????? LOC

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

7782 CLARK??????????? 2450???????? 10 ACCOUNTING?????????? NEW YORK

7839 KING???????????? 5000???????? 10 ACCOUNTING?????????? NEW YORK

7934 MILLER?????????? 1300???????? 10 ACCOUNTING?????????? NEW YORK

7369 SMITH???????????? 800???????? 20 RESEARCH???????????? DALLAS

7566 JONES??????????? 2975???????? 20 RESEARCH???????????? DALLAS

7788 SCOTT??????????? 3000???????? 20 RESEARCH???????????? DALLAS

7876 ADAMS??????????? 1100???????? 20 RESEARCH???????????? DALLAS

7902 FORD???????????? 3000???????? 20 RESEARCH???????????? DALLAS

7499 ALLEN??????????? 1600???????? 30 SALES??????????????? CHICAGO

7521 WARD???????????? 1250???????? 30 SALES??????????????? CHICAGO

7654 MARTIN?????????? 1250???????? 30 SALES??????????????? CHICAGO

7698 BLAKE??????????? 2850???????? 30 SALES??????????????? CHICAGO

7844 TURNER?????????? 1500???????? 30 SALES??????????????? CHICAGO

7900 JAMES???????????? 950???????? 30 SALES??????????????? CHICAGO

14 rows selected.

Execution Plan

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

Plan hash value: 1419571889

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

| Id? | Operation???????????? | Name?????? |

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

|?? 0 | SELECT STATEMENT????? |??????????? |

|?? 1 |? NESTED LOOPS???????? |??????????? |

|?? 2 |?? TABLE ACCESS FULL?? | DEPARTMENT |

|?? 3 |?? TABLE ACCESS CLUSTER| EMPLOYEE?? |

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

Note

-----

- rule based optimizer used (consider using cbo)

Statistics

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

1? recursive calls

0? db block gets

17? consistent gets

0? physical reads

0? redo size

1042? bytes sent via SQL*Net to client

384? bytes received via SQL*Net from client

2? SQL*Net roundtrips to/from client

0? sorts (memory)

0? sorts (disk)

14? rows processed

22:27:09 SQL> select e.empno,e.ename,e.sal,d.dname,d.dname,d.loc from emp e,dept d

22:27:35?? 2? where e.deptno=d.deptno;

EMPNO ENAME???????????? SAL DNAME????????? DNAME????????? LOC

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

7369 SMITH???????????? 800 RESEARCH?????? RESEARCH?????? DALLAS

7499 ALLEN??????????? 1600 SALES????????? SALES????????? CHICAGO

7521 WARD???????????? 1250 SALES????????? SALES????????? CHICAGO

7566 JONES??????????? 2975 RESEARCH?????? RESEARCH?????? DALLAS

7654 MARTIN?????????? 1250 SALES????????? SALES????????? CHICAGO

7698 BLAKE??????????? 2850 SALES????????? SALES????????? CHICAGO

7782 CLARK??????????? 2450 ACCOUNTING???? ACCOUNTING???? NEW YORK

7788 SCOTT??????????? 3000 RESEARCH?????? RESEARCH?????? DALLAS

7839 KING???????????? 5000 ACCOUNTING???? ACCOUNTING???? NEW YORK

7844 TURNER?????????? 1500 SALES????????? SALES????????? CHICAGO

7876 ADAMS??????????? 1100 RESEARCH?????? RESEARCH?????? DALLAS

7900 JAMES???????????? 950 SALES????????? SALES????????? CHICAGO

7902 FORD???????????? 3000 RESEARCH?????? RESEARCH?????? DALLAS

7934 MILLER?????????? 1300 ACCOUNTING???? ACCOUNTING???? NEW YORK

14 rows selected.

Execution Plan

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

Plan hash value: 351108634

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

| Id? | Operation??????????????????? | Name??? | Rows? | Bytes | Cost (%CPU)| Time???? |

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

|?? 0 | SELECT STATEMENT???????????? |???????? |??? 14 |?? 518 |???? 4?? (0)| 00:00:01 |

|?? 1 |? NESTED LOOPS??????????????? |???????? |??? 14 |?? 518 |???? 4?? (0)| 00:00:01 |

|?? 2 |?? TABLE ACCESS FULL????????? | EMP???? |??? 14 |?? 238 |???? 3?? (0)| 00:00:01 |

|?? 3 |?? TABLE ACCESS BY INDEX ROWID| DEPT??? |???? 1 |??? 20 |???? 1?? (0)| 00:00:01 |

|*? 4 |??? INDEX UNIQUE SCAN???????? | PK_DEPT |???? 1 |?????? |???? 0?? (0)| 00:00:01 |

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

Predicate Information (identified by operation id):

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

4 - access("E"."DEPTNO"="D"."DEPTNO")

Statistics

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

139? recursive calls

0? db block gets

59? consistent gets

3? physical reads

0? redo size

1257? bytes sent via SQL*Net to client

384? bytes received via SQL*Net from client

2? SQL*Net roundtrips to/from client

7? sorts (memory)

0? sorts (disk)

14? rows processed

22:27:43 SQL>

3、 rowid ：行號(偽列)精確的定義記錄的物理位置

extended rowid： object id (6)，relative file id(3)，block id (6)，row id(3)

分析rowid

---------普通表和簇表的rowid ，對比

22:31:27 SQL> select rowid ,ename,sal from emp;

ROWID????????????? ENAME???????????? SAL

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

AAACYCAAEAAAAAfAAA SMITH???????????? 800

AAACYCAAEAAAAAfAAB ALLEN??????????? 1600

AAACYCAAEAAAAAfAAC WARD???????????? 1250

AAACYCAAEAAAAAfAAD JONES??????????? 2975

AAACYCAAEAAAAAfAAE MARTIN?????????? 1250

AAACYCAAEAAAAAfAAF BLAKE??????????? 2850

AAACYCAAEAAAAAfAAG CLARK??????????? 2450

AAACYCAAEAAAAAfAAH SCOTT??????????? 3000

AAACYCAAEAAAAAfAAI KING???????????? 5000

AAACYCAAEAAAAAfAAJ TURNER?????????? 1500

AAACYCAAEAAAAAfAAK ADAMS??????????? 1100

AAACYCAAEAAAAAfAAL JAMES???????????? 950

AAACYCAAEAAAAAfAAM FORD???????????? 3000

AAACYCAAEAAAAAfAAN MILLER?????????? 1300

14 rows selected.

22:31:31 SQL> select rowid,deptno,dname from dept;

ROWID????????????????? DEPTNO DNAME

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

AAACYAAAEAAAAAPAAA???????? 10 ACCOUNTING

AAACYAAAEAAAAAPAAB???????? 20 RESEARCH

AAACYAAAEAAAAAPAAC???????? 30 SALES

AAACYAAAEAAAAAPAAD???????? 40 OPERATIONS

22:31:42 SQL> select rowid,id,dname from department;

ROWID????????????????????? ID DNAME

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

AAACZNAAEAAAABWAAA???????? 10 ACCOUNTING

AAACZNAAEAAAABWAAB???????? 20 RESEARCH

AAACZNAAEAAAABWAAC???????? 30 SALES

AAACZNAAEAAAABWAAD???????? 40 OPERATIONS

22:31:58 SQL> select rowid ,eno,ename,sal from employee;

ROWID???????????????????? ENO ENAME???????????? SAL

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

AAACZNAAEAAAABWAAA?????? 7369 SMITH???????????? 800

AAACZNAAEAAAABWAAB?????? 7499 ALLEN??????????? 1600

AAACZNAAEAAAABWAAC?????? 7521 WARD???????????? 1250

AAACZNAAEAAAABWAAD?????? 7566 JONES??????????? 2975

AAACZNAAEAAAABWAAE?????? 7654 MARTIN?????????? 1250

AAACZNAAEAAAABWAAF?????? 7698 BLAKE??????????? 2850

AAACZNAAEAAAABWAAG?????? 7782 CLARK??????????? 2450

AAACZNAAEAAAABWAAH?????? 7788 SCOTT??????????? 3000

AAACZNAAEAAAABWAAI?????? 7839 KING???????????? 5000

AAACZNAAEAAAABWAAJ?????? 7844 TURNER?????????? 1500

AAACZNAAEAAAABWAAK?????? 7876 ADAMS??????????? 1100

AAACZNAAEAAAABWAAL?????? 7900 JAMES???????????? 950

AAACZNAAEAAAABWAAM?????? 7902 FORD???????????? 3000

AAACZNAAEAAAABWAAN?????? 7934 MILLER?????????? 1300

14 rows selected.

DECLARE? v_rowid_type? NUMBER;

v_OBJECT_NUMBER? NUMBER;

v_RELATIVE_FNO?? NUMBER;

v_BLOCK_NUMBERE_FNO?? NUMBER;

v_ROW_NUMBER?? NUMBER;

BEGIN

DBMS_ROWID.rowid_info(rowid_in=>'&num',

rowid_type? =>v_rowid_type,

object_number? =>v_OBJECT_NUMBER,

relative_fno? =>v_RELATIVE_FNO,

block_number? =>v_BLOCK_NUMBERE_FNO,

ROW_NUMBER =>v_ROW_NUMBER);

DBMS_OUTPUT.put_line('ROWID_TYPE:' ||TO_CHAR(v_rowid_type));

DBMS_OUTPUT.put_line('OBJECT_NUMBER:' ||TO_CHAR(v_OBJECT_NUMBER));

DBMS_OUTPUT.put_line('RELATIVE_FNO:' ||TO_CHAR(v_RELATIVE_FNO));

DBMS_OUTPUT.put_line('BLOCK_NUMBER:' ||TO_CHAR(v_BLOCK_NUMBERE_FNO));

DBMS_OUTPUT.put_line('ROW_NUMBER:' ||TO_CHAR(v_ROW_NUMBER));

END;

/

Enter value for num: old?? 7:???? DBMS_ROWID.rowid_info(rowid_in=>'&num',

new?? 7:???? DBMS_ROWID.rowid_info(rowid_in=>'',

PL/SQL procedure successfully completed.

22:36:48 SQL>?????????????????? set serverout on

22:36:53 SQL> /

Enter value for num: AAACZNAAEAAAABWAAA

old?? 7:???? DBMS_ROWID.rowid_info(rowid_in=>'&num',

new?? 7:???? DBMS_ROWID.rowid_info(rowid_in=>'AAACZNAAEAAAABWAAA',

ROWID_TYPE:1

OBJECT_NUMBER:9805

RELATIVE_FNO:4

BLOCK_NUMBER:86

ROW_NUMBER:0

PL/SQL procedure successfully completed

DECLARE? v_rowid_type? NUMBER;

v_OBJECT_NUMBER? NUMBER;

v_RELATIVE_FNO?? NUMBER;

v_BLOCK_NUMBERE_FNO?? NUMBER;

DBMS_OUTPUT.put_line('BLOCK_NUMBER:' ||TO_CHAR(v_BLOCK_NUMBERE_FNO));

v_ROW_NUMBER?? NUMBER;

BEGIN

DBMS_ROWID.rowid_info(rowid_in=>'&num',

rowid_type? =>v_rowid_type,

object_number? =>v_OBJECT_NUMBER,

relative_fno? =>v_RELATIVE_FNO,

block_number? =>v_BLOCK_NUMBERE_FNO,

ROW_NUMBER =>v_ROW_NUMBER);

DBMS_OUTPUT.put_line('ROWID_TYPE:' ||TO_CHAR(v_rowid_type));

DBMS_OUTPUT.put_line('OBJECT_NUMBER:' ||TO_CHAR(v_OBJECT_NUMBER));

DBMS_OUTPUT.put_line('RELATIVE_FNO:' ||TO_CHAR(v_RELATIVE_FNO));

DBMS_OUTPUT.put_line('BLOCK_NUMBER:' ||TO_CHAR(v_BLOCK_NUMBERE_FNO));

DBMS_OUTPUT.put_line('ROW_NUMBER:' ||TO_CHAR(v_ROW_NUMBER));

END;

22:38:10? 19?? /

Enter value for num: AAACZNAAEAAAABWAAM

old?? 7:???? DBMS_ROWID.rowid_info(rowid_in=>'&num',

new?? 7:???? DBMS_ROWID.rowid_info(rowid_in=>'AAACZNAAEAAAABWAAM',

ROWID_TYPE:1

OBJECT_NUMBER:9805

RELATIVE_FNO:4

BLOCK_NUMBER:86

ROW_NUMBER:12

PL/SQL procedure successfully completed.

-------------在建立cluster的表，通過rowid，可以看到不同的表的記錄放在了相同的block 上

22:32:12 SQL>

11:29:43 SQL>

1? DECLARE? v_rowid_type? NUMBER;

2? v_OBJECT_NUMBER? NUMBER;

3? v_RELATIVE_FNO?? NUMBER;

4? v_BLOCK_NUMBERE_FNO?? NUMBER;

5? v_ROW_NUMBER?? NUMBER;

6? BEGIN

7? DBMS_ROWID.rowid_info(rowid_in=>'&num',

8? rowid_type? =>v_rowid_type,

9? object_number? =>v_OBJECT_NUMBER,

10? relative_fno? =>v_RELATIVE_FNO,

11? block_number? =>v_BLOCK_NUMBERE_FNO,

12? ROW_NUMBER =>v_ROW_NUMBER);

13? DBMS_OUTPUT.put_line('ROWID_TYPE:' ||TO_CHAR(v_rowid_type));

14? DBMS_OUTPUT.put_line('OBJECT_NUMBER:' ||TO_CHAR(v_OBJECT_NUMBER));

15? DBMS_OUTPUT.put_line('RELATIVE_FNO:' ||TO_CHAR(v_RELATIVE_FNO));

16? DBMS_OUTPUT.put_line('BLOCK_NUMBER:' ||TO_CHAR(v_BLOCK_NUMBERE_FNO));

17? DBMS_OUTPUT.put_line('ROW_NUMBER:' ||TO_CHAR(v_ROW_NUMBER));

18* END;

/

Enter value for num: AAAMfMAAEAAAAAgAAB

old?? 7: DBMS_ROWID.rowid_info(rowid_in=>'&num',

new?? 7: DBMS_ROWID.rowid_info(rowid_in=>'AAAMfMAAEAAAAAgAAB',

ROWID_TYPE:1

OBJECT_NUMBER:51148

RELATIVE_FNO:4

BLOCK_NUMBER:32

ROW_NUMBER:1

PL/SQL procedure successfully completed.

11:31:54 SQL>

1? select object_name,object_id,object_type ,status from user_objects

2*?? where object_name='EMP'

OBJECT_NAME???????????????????? OBJECT_ID OBJECT_TYPE???????? STATUS

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

EMP???????????????????????????????? 51148 TABLE?????????????? VALID

11:32:56 SQL> COL SEGMENT_NAME FOR A30

11:33:02 SQL>

1? select segment_name,tablespace_name,file_id,block_id from dba_extents

2*?? where segment_name='EMP'

SEGMENT_NAME?????????????????? TABLESPACE_NAME?????????????????? FILE_ID?? BLOCK_ID

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

EMP??????????????????????????? USERS?????????????????????????????????? 4???????? 25

11:33:02 SQL>

11:33:55 SQL> select segment_name,tablespace_name,file_id,block_id,EXTENT_ID,BYTES/1024 from dba_extents

11:34:25?? 2??? where segment_name='EMP';

SEGMENT_NAME?????????????????? TABLESPACE_NAME?????????????????? FILE_ID?? BLOCK_ID? EXTENT_ID BYTES/1024

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

EMP??????????????????????????? USERS?????????????????????????????????? 4???????? 25????????? 0???????? 64

11:34:27 SQL>

總結

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