Oracle 11g Release 1 (11.1)——聚簇和非聚簇的简单查询比较

本文简单比较建立聚簇后，对查询的影响。虽然就几条数据，但多少也能说明点问题。有机会的话，再试下大数据量的比较。

创建 EMPLOYEES 和 DEPTMENTS 表。

-- Create table

create table EMPLOYEES

  EMPNO    NUMBER(4) not null,

  ENAME    VARCHAR2(10),

  JOB      VARCHAR2(9),

  MGR      NUMBER(4),

  HIREDATE DATE,

  SAL      NUMBER(7,2),

  COMM     NUMBER(7,2),

  DEPTNO   NUMBER(3)

tablespace MYTBS

  pctfree 10

  initrans 1

  maxtrans 255

  storage

    initial 64K

    next 1M

    minextents 1

    maxextents unlimited

);

-- Create/Recreate primary, unique and foreign key constraints

alter table EMPLOYEES

  add constraint PK_EMPLOYEES_EMPNO primary key (EMPNO)

  using index

  tablespace MYTBS

  pctfree 10

  initrans 2

  maxtrans 255

  storage

    initial 64K

    next 1M

    minextents 1

    maxextents unlimited

);

-- Create table

create table DEPTMENTS

  DEPTNO NUMBER(3) not null,

  DNAME  VARCHAR2(14),

  LOC    VARCHAR2(13)

tablespace MYTBS

  pctfree 10

  initrans 1

  maxtrans 255

  storage

    initial 64K

    next 1M

    minextents 1

    maxextents unlimited

);

-- Create/Recreate primary, unique and foreign key constraints

alter table DEPTMENTS

  add constraint PK_DEPTMENTS_DEPTNO primary key (DEPTNO)

  using index

  tablespace MYTBS

  pctfree 10

  initrans 2

  maxtrans 255

  storage

    initial 64K

    next 1M

    minextents 1

    maxextents unlimited

);