Oracle的分区表有什么用

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下面对分区表进行简单的实验：

先查询所需要进行分区表的表结构：

sys@FX1TEST>desc fqtbb Name    Null?    Type -------------------------------------------------------------------------- -------- -------------------------------------------------- ID         NUMBER YXTIME      DATE HASH     VARCHAR2(50) GOODLOOK     VARCHAR2(20)

查询表当前的数据：

 sys@FX1TEST>select * from fqtbb;ID YXTIME       HASH    GOODLOOK---------- ------------------- -------------------- ---------- 1 2011-01-02 00:00:00 java111    no 1 2011-04-02 00:00:00 java121    no 1 2011-05-02 00:00:00 java131    no 1 2012-02-02 00:00:00 java141    no 1 2013-01-02 00:00:00 java1ds    no 1 2012-06-04 00:00:00 java1da    no 1 2013-12-21 00:00:00 java771    no 1 2013-02-02 00:00:00 java771    no 1 2014-06-25 00:00:00 java661    no 1 2014-01-02 00:00:00 java156    no 1 2015-05-22 00:00:00 java132    no 1 2015-06-07 00:00:00 java134    no 1 2016-04-21 00:00:00 java152    yes 1 2016-11-11 00:00:00 java761    yes 1 2016-01-21 00:00:00 java171    yes 1 2017-04-21 00:00:00 java711    yes 1 2017-05-05 00:00:00 java717    yes 1 2017-01-02 00:00:00 java174    yes 1 2018-03-01 00:00:00 java172    yes 1 2018-01-23 00:00:00 java176    yes 1 2018-12-22 00:00:00 java166    yes21 rows selected.

下面便是一些常用的分区方法

范围分区：利用分区键定义范围，根据实际取值，进行分区选择，这种范围一般以数字形式存储，例如时间，分数，工资等等，所以不可避免的这种分区方法做不到均匀分区。

这里我们用时间范围进行划分 :

create table fqtbb_part (id number,yxtime date,hash varchar(50),goodlook varchar(20))PARTITION BY RANGE (yxtime)(PARTITION fqtbb_part1 VALUES LESS THAN (TO_DATE('2011-01-01','yyyy-mm-dd'))TABLESPACE test,PARTITION fqtbb_part2 VALUES LESS THAN (TO_DATE('2014-01-02','yyyy-mm-dd'))TABLESPACE test1,PARTITION fqtbb_part3 VALUES LESS THAN (MAXVALUE)TABLESPACE test2);  Table created.

将大表中的数据插到新建表中：

sys@FX1TEST>insert into fqtbb_part select * from fqtbb;21 rows created.sys@FX1TEST>commit;Commit complete.

接下来查询单独分区的数据信息

sys@FX1TEST>select * from fqtbb_part partition(fqtbb_part3);ID YXTIME       HASH    GOODLOOK---------- ------------------- -------------------- ---------- 1 2014-06-25 00:00:00 java661    no 1 2014-01-02 00:00:00 java156    no 1 2015-05-22 00:00:00 java132    no 1 2015-06-07 00:00:00 java134    no 1 2016-04-21 00:00:00 java152    yes 1 2016-11-11 00:00:00 java761    yes 1 2016-01-21 00:00:00 java171    yes 1 2017-04-21 00:00:00 java711    yes 1 2017-05-05 00:00:00 java717    yes 1 2017-01-02 00:00:00 java174    yes 1 2018-03-01 00:00:00 java172    yes 1 2018-01-23 00:00:00 java176    yes 1 2018-12-22 00:00:00 java166    yes13 rows selected.

sys@FX1TEST>select * from fqtbb_part partition(fqtbb_part2);ID YXTIME       HASH    GOODLOOK---------- ------------------- -------------------- ---------- 1 2011-01-02 00:00:00 java111    no 1 2011-04-02 00:00:00 java121    no 1 2011-05-02 00:00:00 java131    no 1 2012-02-02 00:00:00 java141    no 1 2013-01-02 00:00:00 java1ds    no 1 2012-06-04 00:00:00 java1da    no 1 2013-12-21 00:00:00 java771    no 1 2013-02-02 00:00:00 java771    no  8 rows selected.

当然如果查询分区表的信息。也有相对应的表供用户查询。例如：

sys@FX1TEST>select TABLE_NAME,PARTITIONING_TYPE,PARTITION_COUNT,STATUS from dba_part_tables where table_name='FQTBB_PART';TABLE_NAME       PARTITIONING_TYPE  PARTITION_COUNT STATUS------------------------------ ------------------ --------------- ----------------FQTBB_PART       RANGE3 VALID

查询表分区所处的表空间：

sys@FX1TEST>select PARTITION_NAME,NUM_ROWS,TABLESPACE_NAME,SEGMENT_CREATED from dba_tab_partitions where table_name='FQTBB_PART';PARTITION_NAME       NUM_ROWS TABLESPACE SEGMENT_-------------------- ---------- ---------- --------FQTBB_PART1TEST   YESFQTBB_PART2TEST1   YESFQTBB_PART3TEST2   YES

列分区

列分区根据分区键指定的取值列表进行分区，但是这种分区方法适合的比较少，例如部门列表、所属项目组名称等等

这里根据goodlook键进行定义：

create table fqtbb_parta (id number,yxtime date,hash varchar(50),goodlook varchar(20))PARTITION BY list(goodlook)(PARTITION fqtbb_part1 VALUES ('yes')TABLESPACE test,PARTITION fqtbb_part2 VALUES ('no')TABLESPACE test1,PARTITION fqtbb_part3 VALUES (default)TABLESPACE test2);  Table created.

插入数据

sys@FX1TEST>insert into fqtbb_parta select * from fqtbb;21 rows created.sys@FX1TEST>commit;Commit complete.

分区表创建完成之后进行查询验证：

sys@FX1TEST>select * from fqtbb_parta partition(fqtbb_part2);ID YXTIME       HASH    GOODLOOK---------- ------------------- -------------------- ---------- 1 2011-01-02 00:00:00 java111    no 1 2011-04-02 00:00:00 java121    no 1 2011-05-02 00:00:00 java131    no 1 2012-02-02 00:00:00 java141    no 1 2013-01-02 00:00:00 java1ds    no 1 2012-06-04 00:00:00 java1da    no 1 2013-12-21 00:00:00 java771    no 1 2013-02-02 00:00:00 java771    no 1 2014-06-25 00:00:00 java661    no 1 2014-01-02 00:00:00 java156    no 1 2015-05-22 00:00:00 java132    no 1 2015-06-07 00:00:00 java134    no12 rows selected.sys@FX1TEST>select * from fqtbb_parta partition(fqtbb_part1);ID YXTIME       HASH    GOODLOOK---------- ------------------- -------------------- ---------- 1 2016-04-21 00:00:00 java152    yes 1 2016-11-11 00:00:00 java761    yes 1 2016-01-21 00:00:00 java171    yes 1 2017-04-21 00:00:00 java711    yes 1 2017-05-05 00:00:00 java717    yes 1 2017-01-02 00:00:00 java174    yes 1 2018-03-01 00:00:00 java172    yes 1 2018-01-23 00:00:00 java176    yes 1 2018-12-22 00:00:00 java166    yes9 rows selected.sys@FX1TEST>select * from fqtbb_parta partition(fqtbb_part3);no rows selected

下面是oracle 分区表常用的管理操作，如下：

由于我们之前再范围分区时，设置了default值，所以无法增加分区，所以这里先演示删除分区

sys@FX1TEST>alter table fqtbb_part drop partition fqtbb_part3;Table altered.sys@FX1TEST>select PARTITION_NAME,NUM_ROWS,TABLESPACE_NAME,SEGMENT_CREATED from dba_tab_partitions where table_name='FQTBB_PART';PARTITION_NAME       NUM_ROWS TABLESPACE_NAME      SEGMENT_------------------------------------------------------------ ---------- ------------------------------------------------------------ --------FQTBB_PART1      0 TEST     YESFQTBB_PART2      8 TEST1     YES

添加分区

sys@FX1TEST>alter table fqtbb_part add partition p3 values less than (to_date('2019-09-09','yyyy-mm-dd'));Table altered.

截断分区：截断分区是指清楚数据，保留分区结构，如下

sys@FX1TEST>alter table fqtbb_part truncate partition p3;Table truncated.

合并分区：指将相邻的分区合并成一个分区，例如2019、2018 这两个分区，合并之后，分区将采用2019这个界限，并且合并是要合并到2019这个分区里；如下

sys@FX1TEST>alter table fqtbb_part merge partitions fqtbb_part1,fqtbb_part2 into partition fqtbb_part2;Table altered.sys@FX1TEST>select PARTITION_NAME,NUM_ROWS,TABLESPACE_NAME,SEGMENT_CREATED from dba_tab_partitions where table_name='FQTBB_PART';PARTITION_NAME       NUM_ROWS TABLESPACE_NAME      SEGMENT_------------------------------------------------------------ ---------- ------------------------------------------------------------ --------FQTBB_PART2SYSTEM     YESP3SYSTEM     YES

拆分分区：有合并当然就有拆分，意思就是将一个分区拆成两个分区，而之前的分区将不存在；如下

sys@FX1TEST>alter table fqtbb_part split partition fqtbb_part2 at(to_date('2014-01-01','yyyy-mm-dd')) into (partition p1,partition p2);Table altered.sys@FX1TEST>select PARTITION_NAME,NUM_ROWS,TABLESPACE_NAME,SEGMENT_CREATED from dba_tab_partitions where table_name='FQTBB_PART';PARTITION_NAME       NUM_ROWS TABLESPACE_NAME      SEGMENT_------------------------------------------------------------ ---------- ------------------------------------------------------------ --------P1SYSTEM     YESP2SYSTEM     YESP3SYSTEM     YES

重命名分区：顾名思义，就是让分区换一个名字

sys@FX1TEST>alter table fqtbb_part rename partition p1 to p11;Table altered.

感谢各位的阅读，以上就是"Oracle的分区表有什么用"的内容了，经过本文的学习后，相信大家对Oracle的分区表有什么用这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是，小编将为大家推送更多相关知识点的文章，欢迎关注！