Oracle PL/SQL/Index/Create Index
Содержание
- 1 Create a fully indexed table named myCode
- 2 Create an index, and add primary key to use that index
- 3 Create an index reverse
- 4 Created an index based on the uppercase evaluation of the employe"s first name field
- 5 Create index along with the column definition
- 6 Create index for combined columns
- 7 Create index for upper case last name
- 8 Create index on cluster
- 9 Create index with tablespace
- 10 Create Non-Unique index
- 11 Create two indexes for one single table
- 12 CREATE UNIQUE INDEX
- 13 Create unique index and check it in user_ind_columns and user_cons_columns
- 14 create unique index with case ... when statement
- 15 Demonstrate a bitmap join index.
- 16 Function-based Indexes
- 17 indextype is ctxsys.context
- 18 simple index organized table
- 19 To create an index on the LastName column of the Employee table
Create a fully indexed table named myCode
<source lang="sql">
SQL> SQL> create table myCode(
2 codeValue VARCHAR2(1) primary key, 3 Description VARCHAR2(25) 4 );
Table created. SQL> SQL> create index i1 on myCode (codeValue, Description); Index created. SQL> SQL> SQL> drop index i1; Index dropped. SQL> SQL> drop table myCode; Table dropped.
</source>
Create an index, and add primary key to use that index
<source lang="sql">
SQL> SQL> SQL> create table inventory(
2 partno number(4), 3 partdesc varchar2(35), 4 price number(8,2), 5 warehouse varchar2(15));
Table created. SQL> SQL> Create index invent_part_loc_idx
2 On inventory (partno, warehouse) 3 Pctfree 10;
Index created. SQL> SQL> Alter table inventory add (
2 Constraint invent_partno_pk primary key (partno) 3 Using index invent_part_loc_idx);
Table altered. SQL> SQL> drop table inventory; Table dropped. SQL>
</source>
Create an index reverse
<source lang="sql">
SQL> SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
2 ENAME VARCHAR2(10), 3 JOB VARCHAR2(9), 4 MGR NUMBER(4), 5 HIREDATE DATE, 6 SAL NUMBER(7, 2), 7 COMM NUMBER(7, 2), 8 DEPTNO NUMBER(2));
Table created. SQL> SQL> create index emp_empno_pk
2 on emp(empno) reverse;
Index created. SQL> SQL> drop table emp; Table dropped. SQL>
</source>
Created an index based on the uppercase evaluation of the employe"s first name field
<source lang="sql">
SQL> -- create demo table SQL> create table Employee(
2 ID VARCHAR2(4 BYTE) NOT NULL, 3 First_Name VARCHAR2(10 BYTE), 4 Last_Name VARCHAR2(10 BYTE), 5 Start_Date DATE, 6 End_Date DATE, 7 Salary Number(8,2), 8 City VARCHAR2(10 BYTE), 9 Description VARCHAR2(15 BYTE) 10 ) 11 /
Table created. SQL> SQL> -- prepare data SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values ("01","Jason", "Martin", to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto", "Programmer")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("02","Alison", "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 6661.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("03","James", "Smith", to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 6544.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("04","Celia", "Rice", to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2344.78, "Vancouver","Manager")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("05","Robert", "Black", to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("06","Linda", "Green", to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 4322.78,"New York", "Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("07","David", "Larry", to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 7897.78,"New York", "Manager")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("08","James", "Cat", to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 1232.78,"Vancouver", "Tester")
3 /
1 row created. SQL> SQL> SQL> SQL> -- display data in the table SQL> select * from Employee
2 /
ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION
---------- ---------- --------- --------- ---------- ---------- ---------------
01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer 02 Alison Mathews 21-MAR-76 21-FEB-86 6661.78 Vancouver Tester 03 James Smith 12-DEC-78 15-MAR-90 6544.78 Vancouver Tester 04 Celia Rice 24-OCT-82 21-APR-99 2344.78 Vancouver Manager 05 Robert Black 15-JAN-84 08-AUG-98 2334.78 Vancouver Tester 06 Linda Green 30-JUL-87 04-JAN-96 4322.78 New York Tester 07 David Larry 31-DEC-90 12-FEB-98 7897.78 New York Manager 08 James Cat 17-SEP-96 15-APR-02 1232.78 Vancouver Tester 8 rows selected. SQL> SQL> SQL> -- Created an index based on the uppercase evaluation of the employe"s first name field. SQL> SQL> CREATE INDEX employee_idx
2 ON employee (UPPER(first_name));
Index created. SQL> SQL> drop index employee_idx; Index dropped. SQL> SQL> -- clean the table SQL> drop table Employee
2 /
Table dropped. SQL>
</source>
Create index along with the column definition
<source lang="sql">
SQL> SQL> SQL> CREATE TABLE emp2
2 (emp_id NUMBER PRIMARY KEY 3 USING INDEX 4 (CREATE INDEX pk_idx ON emp2(emp_id) TABLESPACE users) 5 ,lastname VARCHAR2(20) CONSTRAINT lastname_create_nn NOT NULL 6 ,firstname VARCHAR2(15) CONSTRAINT firstname_create_nn NOT NULL 7 ,phone VARCHAR2(12) 8 ,company_name VARCHAR2(50) 9 ,CONSTRAINT unique_emp_phone UNIQUE (phone) 10 USING INDEX 11 (CREATE INDEX phone_idx ON emp2 (phone) TABLESPACE users) 12 );
Table created. SQL> SQL> SQL> drop table emp2; Table dropped.
</source>
Create index for combined columns
<source lang="sql">
SQL> SQL> create table emp(
2 emp_id integer primary key 3 ,lastname varchar2(20) not null 4 ,firstname varchar2(15) not null 5 ,midinit varchar2(1) 6 ,street varchar2(30) 7 ,city varchar2(20) 8 ,state varchar2(2) 9 ,zip varchar2(5) 10 ,shortZipCode varchar2(4) 11 ,area_code varchar2(3) 12 ,phone varchar2(8) 13 ,company_name varchar2(50));
Table created. SQL> SQL> create index fullname on emp(lastname, firstname); Index created. SQL> SQL> SQL> drop table emp; Table dropped. SQL> SQL>
</source>
Create index for upper case last name
<source lang="sql">
SQL> SQL> create table emp(
2 emp_id integer primary key 3 ,lastname varchar2(20) not null 4 ,firstname varchar2(15) not null 5 ,midinit varchar2(1) 6 ,street varchar2(30) 7 ,city varchar2(20) 8 ,state varchar2(2) 9 ,zip varchar2(5) 10 ,shortZipCode varchar2(4) 11 ,area_code varchar2(3) 12 ,phone varchar2(8) 13 ,company_name varchar2(50));
Table created. SQL> SQL> create index upper_emp_idx on emp upper(lastname); Index created. SQL> SQL> SQL> drop table emp; Table dropped.
</source>
Create index on cluster
<source lang="sql">
SQL> create cluster user_objects_cluster_btree
2 ( username varchar2(30) ) 3 size 1024 4 /
Cluster created. SQL> SQL> create index user_objects_idx
2 on cluster user_objects_cluster_btree 3 /
Index created. SQL> SQL> drop cluster user_objects_cluster_btree; Cluster dropped. SQL>
</source>
Create index with tablespace
<source lang="sql">
SQL> create table emp (
2 EmpNo NUMBER(10) primary key, 3 Name VARCHAR2(40), 4 DeptNo NUMBER(2), 5 Salary NUMBER(7,2), 6 Birth_Date DATE, 7 Soc_Sec_Num VARCHAR2(9), 8 State_Code CHAR(2) 9 );
SQL> SQL> create index CITY_ST_ZIP_NDX
2 on emp(EmpNo, DeptNo, Soc_Sec_Num) 3 tablespace INDEXES;
SQL> SQL> drop table emp
2 </source>
Create Non-Unique index
<source lang="sql">
SQL> SQL> SQL> CREATE TABLE myTable (
2 myTableID INT PRIMARY KEY NOT NULL, 3 Name VARCHAR(50), 4 PhoneNo VARCHAR(15) DEFAULT "Unknown Phone");
Table created. SQL> SQL> SQL> CREATE INDEX NameIndex ON myTable (Name); Index created.
SQL>
</source>
Create two indexes for one single table
<source lang="sql">
create table indextest as select * from dba_objects where owner in ("OUTLN","PUBLIC","SCOTT","SYS","SYSTEM"); create index indxtest_objname_idx on indextest (object_name) pctfree 10; create index indxtest_objname_fidx on indextest(upper(object_name)); select object_name,owner from indextest where upper(object_name) ="DBA_INDEXES"; select upper(object_name) from indextest; alter table indextest modify object_name NOT NULL; select upper(object_name) from indextest; drop table indextest;
</source>
CREATE UNIQUE INDEX
<source lang="sql">
SQL> SQL> CREATE TABLE myTable (
2 myTableID INT PRIMARY KEY NOT NULL, 3 Name VARCHAR(50), 4 PhoneNo VARCHAR(15) DEFAULT "Unknown Phone");
Table created. SQL> SQL> CREATE UNIQUE INDEX NameIndex ON myTable (Name); Index created. SQL> SQL> drop table myTable; Table dropped.
</source>
Create unique index and check it in user_ind_columns and user_cons_columns
<source lang="sql">
SQL> SQL> set echo off SQL> create table emp(
2 emp_id integer primary key 3 ,lastname varchar2(20) constraint lastname_create_nn not null 4 ,firstname varchar2(15) constraint firstname_create_nn not null 5 ,midinit varchar2(1) 6 ,street varchar2(30) 7 ,city varchar2(20) 8 ,state varchar2(2) 9 ,zip varchar2(5) 10 ,shortZipCode varchar2(4) 11 ,area_code varchar2(3) 12 ,phone varchar2(8) 13 ,company_name varchar2(50));
Table created. SQL> SQL> create unique index pk_idx on emp (emp_id); SQL> SQL> select index_name, table_name, column_name from user_ind_columns where table_name = "EMP";
SQL> SQL> select constraint_name, table_name, column_name from user_cons_columns where table_name = "EMP"; SQL> SQL> SQL> drop table emp cascade constraints; Table dropped. SQL>
</source>
create unique index with case ... when statement
<source lang="sql">
SQL> create table registrations
2 ( attendee NUMBER(4) 3 , course VARCHAR2(6) 4 , begindate DATE 5 , evaluation NUMBER(1) 6 , constraint R_PK primary key(attendee,course,begindate) 7 ) ;
Table created. SQL> SQL> insert into registrations values (8,"JAV",date "2009-12-13",5 ); 1 row created. SQL> insert into registrations values (9,"JAV",date "2009-12-13",4 ); 1 row created. SQL> insert into registrations values (4,"JAV",date "2000-02-01",3 ); 1 row created. SQL> insert into registrations values (8,"JAV",date "2000-02-01",4 ); 1 row created. SQL> insert into registrations values (6,"JAV",date "2000-02-01",5 ); 1 row created. SQL> insert into registrations values (12,"XML",date "2000-02-03",4 ); 1 row created. SQL> insert into registrations values (2,"XML",date "2000-02-03",5 ); 1 row created. SQL> insert into registrations values (4,"PLS",date "2000-09-11",NULL); 1 row created. SQL> insert into registrations values (2,"PLS",date "2000-09-11",NULL); 1 row created. SQL> insert into registrations values (11,"PLS",date "2000-09-11",NULL); 1 row created. SQL> SQL> create unique index oau_reg on registrations
2 ( case course when "OAU" then attendee else null end 3 , case course when "OAU" then course else null end );
Index created. SQL> SQL> insert into registrations values (12,"OAU",sysdate,null); 1 row created. SQL> SQL> drop index oau_reg; Index dropped. SQL> drop table registrations; Table dropped.
</source>
Demonstrate a bitmap join index.
<source lang="sql">
SQL> SQL> SQL> CREATE TABLE EMP(
2 EMPNO NUMBER(4) NOT NULL, 3 ENAME VARCHAR2(10), 4 JOB VARCHAR2(9), 5 MGR NUMBER(4), 6 startDate DATE, 7 SAL NUMBER(7, 2), 8 COMM NUMBER(7, 2), 9 DEPTNO NUMBER(2) 10 );
Table created. SQL> SQL> INSERT INTO EMP VALUES(7369, "SMITH", "CLERK", 7902,TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7499, "ALLEN", "SALESMAN", 7698,TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7521, "WARD", "SALESMAN", 7698,TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7566, "JONES", "MANAGER", 7839,TO_DATE("2-APR-1981", "DD-MON-YYYY"), 2975, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES(7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES(7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7900, "E", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10); 1 row created. SQL> SQL> CREATE TABLE DEPT(
2 DEPTNO NUMBER(2), 3 DNAME VARCHAR2(14), 4 LOC VARCHAR2(13) 5 );
Table created. SQL> SQL> INSERT INTO DEPT VALUES (10, "ACCOUNTING", "NEW YORK"); 1 row created. SQL> INSERT INTO DEPT VALUES (20, "RESEARCH", "DALLAS"); 1 row created. SQL> INSERT INTO DEPT VALUES (30, "SALES", "CHICAGO"); 1 row created. SQL> INSERT INTO DEPT VALUES (40, "OPERATIONS", "BOSTON"); 1 row created. SQL> SQL> select count(*) from emp, dept where emp.deptno = dept.deptno and dept.dname = "SALES";
COUNT(*)
6
1 row selected.
Execution Plan
Plan hash value: 2157540364
| Id | Operation | Name |
| 0 | SELECT STATEMENT | | | 1 | SORT AGGREGATE | | | 2 | MERGE JOIN | | | 3 | SORT JOIN | | |* 4 | TABLE ACCESS FULL| DEPT | |* 5 | SORT JOIN | | | 6 | TABLE ACCESS FULL| EMP |
Predicate Information (identified by operation id):
4 - filter("DEPT"."DNAME"="SALES")
5 - access("EMP"."DEPTNO"="DEPT"."DEPTNO")
filter("EMP"."DEPTNO"="DEPT"."DEPTNO")
Note
- rule based optimizer used (consider using cbo)
Statistics
1 recursive calls
0 db block gets
6 consistent gets
0 physical reads
0 redo size
411 bytes sent via SQL*Net to client
380 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
2 sorts (memory)
0 sorts (disk)
1 rows processed
SQL> SQL> set autotrace off; SQL> SQL> drop table emp; Table dropped. SQL> drop table dept; Table dropped. SQL> SQL>
</source>
Function-based Indexes
<source lang="sql">
SQL> SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
2 ENAME VARCHAR2(10), 3 JOB VARCHAR2(9), 4 MGR NUMBER(4), 5 HIREDATE DATE, 6 SAL NUMBER(7, 2), 7 COMM NUMBER(7, 2), 8 DEPTNO NUMBER(2));
Table created. SQL> SQL> create index upper_name_idx on emp(upper(ename)); Index created. SQL> SQL> SQL> drop table EMP; Table dropped. SQL> SQL>
</source>
indextype is ctxsys.context
<source lang="sql">
SQL> SQL> SQL> create table t ( x clob ); Table created. SQL> SQL> set autotrace traceonly explain SQL> select * from t; Execution Plan
Plan hash value: 1601196873
| Id | Operation | Name |
| 0 | SELECT STATEMENT | | | 1 | TABLE ACCESS FULL| T |
Note
- rule based optimizer used (consider using cbo)
SQL> SQL> create index t_idx on t(x) indextype is ctxsys.context; Index created. SQL> select * from t; Execution Plan
Plan hash value: 1601196873
| Id | Operation | Name | Rows | Bytes | Cost |
| 0 | SELECT STATEMENT | | 82 | 8200 | 1 | | 1 | TABLE ACCESS FULL| T | 82 | 8200 | 1 |
Note
- cpu costing is off (consider enabling it)
SQL> SQL> set autotrace off SQL> SQL> drop table t; Table dropped.
</source>
simple index organized table
<source lang="sql">
SQL> SQL> create table states (
2 state_id varchar2(2), 3 state_name varchar2(20), 4 constraint states_pk 5 primary key (state_id) 6 ) 7 organization index 8 /
Table created. SQL> SQL> drop table states; Table dropped. SQL>
</source>
To create an index on the LastName column of the Employee table
<source lang="sql">
SQL> -- create demo table SQL> create table Employee(
2 ID VARCHAR2(4 BYTE) NOT NULL, 3 First_Name VARCHAR2(10 BYTE), 4 Last_Name VARCHAR2(10 BYTE), 5 Start_Date DATE, 6 End_Date DATE, 7 Salary Number(8,2), 8 City VARCHAR2(10 BYTE), 9 Description VARCHAR2(15 BYTE) 10 ) 11 /
Table created. SQL> SQL> -- prepare data SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values ("01","Jason", "Martin", to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto", "Programmer")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("02","Alison", "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 6661.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("03","James", "Smith", to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 6544.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("04","Celia", "Rice", to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2344.78, "Vancouver","Manager")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("05","Robert", "Black", to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("06","Linda", "Green", to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 4322.78,"New York", "Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("07","David", "Larry", to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 7897.78,"New York", "Manager")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("08","James", "Cat", to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 1232.78,"Vancouver", "Tester")
3 /
1 row created. SQL> SQL> SQL> SQL> -- display data in the table SQL> select * from Employee
2 /
ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION
---------- ---------- --------- --------- ---------- ---------- ---------------
01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer 02 Alison Mathews 21-MAR-76 21-FEB-86 6661.78 Vancouver Tester 03 James Smith 12-DEC-78 15-MAR-90 6544.78 Vancouver Tester 04 Celia Rice 24-OCT-82 21-APR-99 2344.78 Vancouver Manager 05 Robert Black 15-JAN-84 08-AUG-98 2334.78 Vancouver Tester 06 Linda Green 30-JUL-87 04-JAN-96 4322.78 New York Tester 07 David Larry 31-DEC-90 12-FEB-98 7897.78 New York Manager 08 James Cat 17-SEP-96 15-APR-02 1232.78 Vancouver Tester 8 rows selected. SQL> SQL> SQL> SQL> SQL> SQL> --To create an index on the LastName column of the Employee table SQL> SQL> CREATE INDEX LastNameIndex
2 ON Employee (Last_Name);
Index created. SQL> SQL> SQL> drop index LastNameIndex; Index dropped. SQL> SQL> SQL> SQL> SQL> -- clean the table SQL> drop table Employee
2 /
Table dropped. SQL> SQL> SQL>
</source>
