Oracle PL/SQL Tutorial/Index/Functional Index
Содержание
Create a calculated index
<source lang="sql">
SQL> SQL> SQL> create table employees(
2 empno NUMBER(4) 3 , ename VARCHAR2(8) 4 , init VARCHAR2(5) 5 , job VARCHAR2(8) 6 , mgr NUMBER(4) 7 , bdate DATE 8 , msal NUMBER(6,2) 9 , comm NUMBER(6,2) 10 , deptno NUMBER(2) ) ;
Table created. SQL> SQL> SQL> insert into employees values(1,"Jason", "N", "TRAINER", 2, date "1965-12-18", 800 , NULL, 10); 1 row created. SQL> insert into employees values(2,"Jerry", "J", "SALESREP",3, date "1966-11-19", 1600, 300, 10); 1 row created. SQL> insert into employees values(3,"Jord", "T" , "SALESREP",4, date "1967-10-21", 1700, 500, 20); 1 row created. SQL> insert into employees values(4,"Mary", "J", "MANAGER", 5, date "1968-09-22", 1800, NULL, 20); 1 row created. SQL> insert into employees values(5,"Joe", "P", "SALESREP",6, date "1969-08-23", 1900, 1400, 30); 1 row created. SQL> insert into employees values(6,"Black", "R", "MANAGER", 7, date "1970-07-24", 2000, NULL, 30); 1 row created. SQL> insert into employees values(7,"Red", "A", "MANAGER", 8, date "1971-06-25", 2100, NULL, 40); 1 row created. SQL> insert into employees values(8,"White", "S", "TRAINER", 9, date "1972-05-26", 2200, NULL, 40); 1 row created. SQL> insert into employees values(9,"Yellow", "C", "DIRECTOR",10, date "1973-04-27", 2300, NULL, 20); 1 row created. SQL> insert into employees values(10,"Pink", "J", "SALESREP",null,date "1974-03-28", 2400, 0, 30); 1 row created. SQL> SQL> SQL> SQL> create index year_sal_idx
2 on employees (12*msal + coalesce(comm,0));
Index created. SQL> SQL> drop table employees; Table dropped. SQL></source>
Create index on upper case string value
<source lang="sql">
SQL> SQL> CREATE TABLE employee
2 (employee_id NUMBER(7), 3 last_name VARCHAR2(25), 4 first_name VARCHAR2(25), 5 userid VARCHAR2(8), 6 start_date DATE, 7 comments VARCHAR2(255), 8 manager_id NUMBER(7), 9 title VARCHAR2(25), 10 department_id NUMBER(7), 11 salary NUMBER(11, 2), 12 commission_pct NUMBER(4, 2) 13 );
Table created. SQL> SQL> INSERT INTO employee VALUES (1, "V", "Ben", "cv",to_date("03-MAR-90 8:30", "dd-mon-yy hh24:mi"),NULL, NULL, "PRESIDENT", 50, 2500, NULL); 1 row created. SQL> INSERT INTO employee VALUES (2, "N", "Haidy", "ln", "08-MAR-90", NULL,1, "VP, OPERATIONS", 41, 1450, NULL); 1 row created. SQL> INSERT INTO employee VALUES (3, "N", "Molly", "mn", "17-JUN-91",NULL, 1, "VP, SALES", 31, 1400, NULL); 1 row created. SQL> INSERT INTO employee VALUES (4, "S", "Mark", "mq", "07-APR-90",NULL, 1, "VP, FINANCE", 10, 1450, NULL); 1 row created. SQL> INSERT INTO employee VALUES (5, "R", "AUDRY", "ar", "04-MAR-90",NULL, 1, "VP, ADMINISTRATION", 50, 1550, NULL); 1 row created. SQL> INSERT INTO employee VALUES (6, "U", "MOLLY", "mu", "18-JAN-91",NULL, 2, "WAREHOUSE MANAGER", 41, 1200, NULL); 1 row created. SQL> INSERT INTO employee VALUES (7, "M", "ROBERTA", "rm", "14-MAY-90",NULL, 2, "WAREHOUSE MANAGER", 41, 1250, NULL); 1 row created. SQL> INSERT INTO employee VALUES (8, "B", "BEN", "ry", "07-APR-90", NULL, 2,"WAREHOUSE MANAGER", 41, 1100, NULL); 1 row created. SQL> INSERT INTO employee VALUES (9, "C", "Jane", "ac", "09-FEB-92",NULL, 2, "WAREHOUSE MANAGER", 41, 1300, NULL); 1 row created. SQL> INSERT INTO employee VALUES (10, "H", "Mart", "mh", "27-FEB-91", NULL, 2,"WAREHOUSE MANAGER", 41, 1307, NULL); 1 row created. SQL> SQL> CREATE INDEX employee_idx2 ON employee(UPPER(last_name)); Index created. SQL> SQL> SELECT employee_id, last_name, first_name
2 FROM employee 3 WHERE UPPER(last_name) = "NEWMAN";
no rows selected SQL> SQL> SELECT /*+ NO_INDEX (employee) */ first_name,
2 last_name 3 FROM employee 4 WHERE employee_id = 25;
no rows selected SQL> SQL> SQL> drop table employee; Table dropped. SQL> SQL></source>
Functional index
<source lang="sql">
SQL> SQL> SQL> SQL> -- create demo table SQL> create table Employee(
2 ID VARCHAR2(4 BYTE) NOT NULL primary key, 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> CREATE UNIQUE INDEX unique_upper
2 ON employee ( 3 UPPER(first_name), 4 UPPER(last_name), 5 start_date 6 );
Index created. SQL> SQL> drop index unique_upper; Index dropped. SQL> SQL> -- clean the table SQL> drop table Employee
2 /
Table dropped.</source>
Index based on case statement
<source lang="sql">
SQL> SQL> create table registrations
2 ( attendee NUMBER(4) 3 , course VARCHAR2(6) 4 , begindate DATE 5 , evaluation NUMBER(1)) ;
Table created. SQL> SQL> SQL> insert into registrations values (1, "SQL",date "1999-04-12",4 ); 1 row created. SQL> insert into registrations values (2, "SQL",date "1999-12-13",NULL); 1 row created. SQL> insert into registrations values (3, "SQL",date "1999-12-13",NULL); 1 row created. SQL> insert into registrations values (4, "OAU",date "1999-08-10",4 ); 1 row created. SQL> insert into registrations values (5, "OAU",date "2000-09-27",5 ); 1 row created. SQL> insert into registrations values (6, "JAV",date "1999-12-13",2 ); 1 row created. SQL> insert into registrations values (7, "JAV",date "2000-02-01",4 ); 1 row created. SQL> insert into registrations values (8, "JAV",date "2000-02-01",5 ); 1 row created. SQL> insert into registrations values (9, "XML",date "2000-02-03",4 ); 1 row created. SQL> insert into registrations values (10,"XML",date "2000-02-03",5 ); 1 row created. SQL> insert into registrations values (1, "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 (3, "PLS",date "2000-09-11",NULL); 1 row created. SQL> 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 (7900,"OAU",sysdate,null); 1 row created. SQL> SQL> drop index oau_reg; Index dropped. SQL> SQL> SQL> drop table registrations; Table dropped. SQL></source>