oracle分区表性能比较案例

oracle分区表性能比较案例

--1.创建两张表: part_tab(分区表),no_part_tab(普通表)
CREATE TABLE part_tab
( c1 int default NULL, c2 varchar2(30) default NULL, c3 date not null)
PARTITION BY RANGE(year(c3))
(
PARTITION p0 VALUES LESS THAN (1995),
PARTITION p1 VALUES LESS THAN (1996) ,
PARTITION p2 VALUES LESS THAN (1997) ,
PARTITION p3 VALUES LESS THAN (1998) ,
PARTITION p4 VALUES LESS THAN (1999) ,
PARTITION p5 VALUES LESS THAN (2000) ,
PARTITION p6 VALUES LESS THAN (2001) ,
PARTITION p7 VALUES LESS THAN (2002) ,
PARTITION p8 VALUES LESS THAN (2003) ,
PARTITION p9 VALUES LESS THAN (2004) ,
PARTITION p10 VALUES LESS THAN (2010),
PARTITION p11 VALUES LESS THAN (MAXVALUE) 
);


CREATE TABLE no_part_tab
( c1 int default NULL, c2 varchar2(30) default NULL, c3 date not null)；
 

--2.用存储过程插入800万条数据
CREATE PROCEDURE load_part_tab()
    begin
    declare v int default 0;
    while v < 8000000
    do
        insert into part_tab
        values (v,'testingpartitions',adddate('1995-01-01',(rand(v)*36520)mod 3652));
        set v = v + 1;
    end while;
end;

insert into no_part_tab  select * from part_tab;

--3.测试sql性能

--查询分区表：
select count(*) from part_tab where c3 > date '1995-01-01'and c3 < date '1995-12-31';
--1 row in set (2.62 sec)

--查询普通表：
select count(*) from part_tab where c3 > date '1995-01-01'and c3 < date '1995-12-31';
--1 row in set (7.33 sec)
-- 分区表的执行时间比普通表少70%。


--4.通过explain语句来分析执行情况
explain select count(*) from part_tab where c3 > date '1995-01-01'and c3 < date '1995-12-31';

--+----+-------------+----------+------+---------------+------+---------+------+---------+-------------+

--| id |select_type | table    | type |possible_keys | key  | key_len | ref  | rows   | Extra       |

--+----+-------------+----------+------+---------------+------+---------+------+---------+-------------+

--|  1 | SIMPLE      | part_tab | ALL  | NULL          | NULL | NULL    | NULL | 7980796 | Using where |

--+----+-------------+----------+------+---------------+------+---------+------+---------+-------------+

--1 rowin set

explain select count(*) from no_part_tab where c3 > date '1995-01-01'and c3 < date '1995-12-31';

--+----+-------------+-------------+------+---------------+------+---------+------+---------+-------------+
--
--| id |select_type | table       | type |possible_keys | key  | key_len | ref  | rows   | Extra       |
--
--+----+-------------+-------------+------+---------------+------+---------+------+---------+-------------+
--
--|  1 | SIMPLE      | no_part_tab | ALL  | NULL          | NULL | NULL    | NULL | 8000206 | Using where |
--
--+----+-------------+-------------+------+---------------+------+---------+------+---------+-------------+
--
--1 rowin set

分区表执行扫描了7980796行，而普通表则扫描了8000206行。