UNIQUE约束创建非聚集索引,而PRIMARY KEY则会创建聚集索引,除非已经存在一个。 What are the replication differences between PostgreSQL and SQL Server? Compare replication in PostgreSQL vs. MSSQL 中文:两种数据库的复制功能比较 遵循发布和订阅模型。这种复制方法称为逻辑复制,因为更改基于数据的复制标识符(例如,主...
UNIQUE约束创建非聚集索引,而PRIMARY KEY则会创建聚集索引,除非已经存在一个。 What are the replication differences between PostgreSQL and SQL Server? Compare replication in PostgreSQL vs. MSSQL 中文:两种数据库的复制功能比较 遵循发布和订阅模型。这种复制方法称为逻辑复制,因为更改基于数据的复制标识符(例如,主...
代码语言:javascript 代码运行次数:0 运行 AI代码解释 CREATE [ UNIQUE ] INDEX [ CONCURRENTLY ] [ [ IF NOT EXISTS ] name ] ON [ ONLY ] table_name [ USING method ] ( { column_name | ( expression ) } [ COLLATE collation ] [ opclass [ ( opclass_parameter = value [, ... ] ) ] ...
主键总是唯一且非空,InnoDB自动对它建立了索引(primary key),对于非主键字段上建立的索引,又称辅助索引,索引排列也是顺序排列,只是它还附带一个本条记录的主键值的数据域,不是指向本数据行的指针。 在使用辅助索引查找时,先找到对应这一列的索引值,再根据索引节点上的另一个数据域---主键值,来查找该行记录,即...
存储在 R 树上的索引，例如在空间数据类型上找到的索引存储在 B 树上的索引，例如 PRIMARY KEY、INDEX、FULLTEXT 和 UNIQUE使用 FULLTEXT 索引时的倒排列表和哈希索引 安全 PostgreSQL和MySQL都支持组和用户管理，并为各种角色授予SQL权限。MySQL 支持本机窗口服务、PAM 和 LDAP 进行用户身份验证，而 PostgreSQL 支持...
Non_unique:0Key_name: PRIMARY Seq_in_index:1Column_name: id Collation: A Cardinality:4Sub_part: NULL Packed: NULL Null: Index_type: BTREE Comment: Index_comment:*** 2. row ***Table: tx Non_unique:1Key_name: tx_num_index Seq_in_index:1Column_name: num ...
Now if we insert the same value ofidagain, it errors out with a duplicate key violation because of the unique primary key: postgres=>INSERTINTOblogVALUES(1,'AWS Blog1');ERROR:duplicatekeyvalueviolatesuniqueconstraint"blog_pkey"DETAIL:Key(n)=(1)alreadyexists. ...
However, if you do support the unique features that Slonik adds, the opinionated API design, and are not afraid of adopting a technology in its young days, then I warmly invite you to adopt Slonik and become a contributor to what I intend to make the standard PostgreSQL client in the ...
CREATETABLEdevice_types( device_type_idintprimary key, device_type_nametextnot nullunique );--replicate the table across all nodes to enable foreign keys and joins on any columnSELECTcreate_reference_table('device_types');--insert a device typeINSERT INTOdevice_types (device_type_id, device_...
save_point_1; SAVEPOINT for_test=# INSERT INTO consumers(id, consumer_id) VALUES (3, 'Bob'); INSERT 0 1 for_test=# INSERT INTO consumers(id, consumer_id) VALUES (1, 'Harry'); ERROR: duplicate key value violates unique constraint "consumers_pk" DETAIL: Key (id)=(1) already exists...