云数据库OceanBase入门教程 OceanBase CREATE TABLE

2024-02-26 开发教程 云数据库OceanBase入门教程 匿名 4

描述

该语句用来在数据库中创建一张新表。

格式

CREATE [GLOBAL TEMPORARY] TABLE table_name
(table_definition_list) [table_option_list] [partition_option] [on_commit_option]
CREATE [GLOBAL TEMPORARY] TABLE table_name
(table_definition_list) [table_option_list] [partition_option] [AS] select;
table_definition_list:
table_definition [, table_definition ...]
table_definition:
column_definition
| INDEX [index_name] index_desc
| [CONSTRAINT [constraint_name]] [PRIMARY KEY|UNIQUE] (column_desc_list) [USING INDEX index_option_list]
| [CONSTRAINT [constraint_name]] FOREIGN KEY (column_name, column_name ...) references_clause constranit_state
| [CONSTRAINT [constraint_name]] CHECK(expression) constranit_state
column_definition_list:
column_definition [, column_definition ...]
column_definition:
column_name data_type
[VISIBLE|INVISIBLE]
{
[DEFAULT expression]
[NULL | NOT NULL]
[CONSTRAINT [constraint_name] [PRIMARY] KEY] [UNIQUE [KEY]]
[CONSTRAINT [constraint_name] CHECK(expression) constranit_state]
[CONSTRAINT [constraint_name] references_clause
|
[GENERATED ALWAYS] AS (expression) [VIRTUAL]
[NULL | NOT NULL] [UNIQUE KEY] [[PRIMARY] KEY] [UNIQUE LOWER_KEY] [COMMENT string]
}
references_clause:
REFERENCES table_name [ (column_name, column_name ...) ] [ON DELETE {CASCADE}]]
constranit_state:
[RELY|NORELY] [USING INDEX index_option_list] [ENABLE|DISABLE] [VALIDATE|NOVALIDATE]
index_desc:
(column_desc_list) [index_option_list]
column_desc_list:
column_desc [, column_desc ...]
column_desc:
column_name [ASC | DESC][NULL LAST|NULL FIRST]
index_option_list:
index_option [ index_option ...]
index_option:
[GLOBAL | LOCAL]
| block_size
| compression
| STORING(column_name_list)
| comment
table_option_list:
table_option [ table_option ...]
table_option:
primary_zone
| replica_num
| table_tablegroup
| block_size
| compression
| comment
| DUPLICATE_SCOPE [=] "none|zone|region|cluster"
| LOCALITY [=] "locality description"
| ENABLE ROW MOVEMENT
| DISABLE ROW MOVEMENT
| physical_attribute
physical_attribute_list:
physical_attribute [physical_attribute]
physical_attribute:
PCTFREE [=] num
| PCTUSED num
| INITRANS num
| MAXTRANS num
| STORAGE(storage_option [storage_option] ...)
| TABLESPACE tablespace
compression:
NOCOMPRESS
| COMPRESS { BASIC | FOR OLTP | FOR QUERY [LOW|HIGH] | FOR ARCHIVE [LOW|HIGH]}
storage_option:
INITIAL_ num [K|M|G|T|P|E]
| NEXT num [K|M|G|T|P|E]
| MINEXTENTS num [K|M|G|T|P|E]
| MAXEXTENTS num [K|M|G|T|P|E]
partition_option:
PARTITION BY HASH(column_name_list)
[subpartition_option] hash_partition_define
| PARTITION BY RANGE (column_name_list)
[subpartition_option] (range_partition_list)
| PARTITION BY LIST (column_name_list)
[subpartition_option] (list_partition_list)
/*模板化二级分区*/
subpartition_option:
SUBPARTITION BY HASH (column_name_list) hash_subpartition_define
| SUBPARTITION BY RANGE (column_name_list) SUBPARTITION TEMPLATE
(range_subpartition_list)
| SUBPARTITION BY LIST (column_name_list) SUBPARTITION TEMPLATE
(list_subpartition_list)
/*非模板化二级分区*/
subpartition_option:
SUBPARTITION BY HASH (column_name_list)
| SUBPARTITION BY RANGE (column_name_list)
| SUBPARTITION BY LIST (column_name_list)
subpartition_list:
(hash_subpartition_list)
| (range_subpartition_list)
| (list_subpartition_list)
hash_partition_define:
PARTITIONS partition_count [TABLESPACE tablespace] [compression]
| (hash_partition_list)
hash_partition_list:
hash_partition [, hash_partition, ...]
hash_partition:
partition [partition_name] [subpartition_list/*仅非模板化二级分区可定义*/]
hash_subpartition_define:
SUBPARTITIONS subpartition_count
| SUBPARTITION TEMPLATE (hash_subpartition_list)
hash_subpartition_list:
hash_subpartition [, hash_subpartition, ...]
hash_subpartition:
subpartition [subpartition_name]
range_partition_list:
range_partition [, range_partition ...]
range_partition:
PARTITION [partition_name]
VALUES LESS THAN {(expression_list) | (MAXVALUE)}
[subpartition_list/*仅非模板化二级分区可定义*/]
[ID = num] [physical_attribute_list] [compression]
range_subpartition_list:
range_subpartition [, range_subpartition ...]
range_subpartition:
SUBPARTITION subpartition_name
VALUES LESS THAN {(expression_list) | MAXVALUE} [physical_attribute_list]
list_partition_list:
list_partition [, list_partition] ...
list_partition:
PARTITION [partition_name]
VALUES (DEFAULT|expression_list)
[subpartition_list/*仅非模板化二级分区可定义*/]
[ID num] [physical_attribute_list] [compression]
list_subpartition_list:
list_subpartition [, list_subpartition] ...
list_subpartition:
SUBPARTITION [partition_name] VALUES (DEFAULT|expression_list) [physical_attribute_list]
expression_list:
expression [, expression ...]
column_name_list:
column_name [, column_name ...]
partition_name_list:
partition_name [, partition_name ...]
partition_count | subpartition_count:
INT_VALUE
on_commit_option:
ON COMMIT DELETE ROWS
| ON COMMIT PRESERVE ROWS

参数说明

参数

描述

DUPLICATE_SCOPE

用来指定复制表属性,取值如下:

  • none:表示该表是一个普通表

  • zone:表示该表是一个复制表,leader 需要将事务复制到本 zone 的所有 F 副本及 R 副本

  • region:表示该表是一个复制表,leader 需要将事务复制到本 region 的所有 F 副本及 R 副本

  • cluster:表示该表是一个复制表,leader 需要将事务复掉到 cluster 的所有 F 副本及 R 副本

不指定 DUPLICATE_SCOPE 的情况下,默认值为 none。

BLOCK_SIZE

指定表的微块大小

COMPRESSION

指定存储格式 flat/encoding 以及压缩方法,对应如下:

  • nocompress:flat 格式, none 压缩

  • compress [basic]:flat 格式, lz4_1.0 压缩

  • compress for oltp:flat 格式, zstd_1.0 压缩

  • query [low|high]:encoding 格式, lz4_1.0 压缩

  • archive [low|high]:encoding 格式, zstd_1.0 压缩

primary_zone

指定主 Zone(副本 Leader 所在 Zone)。

replica_num

指定副本数。

table_tablegroup

指定表所属的 talegroup。

comment

注释。

LOCALITY

描述副本在 Zone 间的分布情况,如:F@z1,F@z2,F@z3,R@z4 表示 z1, z2, z3 为全功能副本,z4 为只读副本。

physical_attribute

PCTFREE: 指定宏块保留空间百分比

其它属性:STORAGE, TABLESPACE 等仅为了语法兼容方便迁移,不生效

ENABLE/DISABLE ROW MOVEMENT

是否允许更会致行在不同分区间移动的分区键更新

ON COMMIT DELETE ROWS

事务级临时表:提交时删除数据

ON COMMIT PRESERVE ROWS

会话级临时表:会话结束时删除数据

示例

  • 创建数据库表。

CREATE TABLE test (c1 INT PRIMARY KEY, c2 VARCHAR(50)) REPLICA_NUM = 3, PRIMARY_ZONE = 'zone1';
  • 创建一个复制表。

CREATE TABLE item (i_id INT
, i_name VARCHAR(24)
, i_price DECIMAL(5,2)
, i_data VARCHAR(50)
, i_im_id INT
, PRIMARY KEY(i_id)) COMPRESS FOR QUERY pctfree=0 BLOCK_SIZE=16384
DUPLICATE_SCOPE='cluster' LOCALITY='F@zone1, F@zone2,R{all_server}@zone3' primary_zone='zone1';
  • 创建带索引的表。

create table t1 (c1 int primary key, c2 int, c3 int, index i1 (c2));
  • 创建 hash 分区,分区数为 8 的表。

create table t1 (c1 int primary key, c2 int) partition by hash(c1) partitions 8;
  • 创建一级分区为 range 分区,二级分区为 hash 分区的表。

create table t1 (c1 int, c2 int, c3 int)
partition by range(c1) subpartition by hash(c2) subpartitions 5
(partition p0 values less than(0), partition p1 values less than(100));
  • 开启 encoding 并使用 zstd 压缩,宏块保留空间为 5%。

create table t1 (c1 int, c2 int, c3 varchar(64))
COMPRESS FOR ARCHIVE
PCTFREE 5;
  • 创建一个事务级临时表。

create global temporary table t1 (c1 int) on commit delete rows ;
  • 创建一个带约束的表。

create table t1 (c1 int, c2 int, c3 int, CONSTRAINT equal_check CHECK(c2 = c3 * 2) ENABLE VALIDATE);
  • 创建非模板化的二级分区表。

create table t_range_range1 (c1 int, c2 int, c3 int) partition by range(c1)
subpartition by range (c2)
(
partition p0 values less than (100)
(
subpartition p0_r1 values less than (100),
subpartition p0_r2 values less than (200),
subpartition p0_r3 values less than (300)
),
partition p1 values less than (200)
(
subpartition p1_r1 values less than (100),
subpartition p1_r2 values less than (200),
subpartition p1_r3 values less than (300)
),
partition p2 values less than (300)
(
subpartition p2_r1 values less than (100),
subpartition p2_r2 values less than (200),
subpartition p2_r3 values less than (300)
)
);