AntDB入门手册——建索引之唯一索引

antdb=# create unique index idx_t_count_unique_id on t_count (id);
CREATE INDEX
antdb=# \di+ idx_t_count_unique_id
                                  List of relations
 Schema |         Name          | Type  | Owner  |  Table  |    Size    | Description 
--------+-----------------------+-------+--------+---------+------------+-------------
 public | idx_t_count_unique_id | index | danghb | t_count | 8192 bytes | 
(1 row)

目前由于AntDB的限制，在创建唯一索引的时候，唯一键须包含分片键，否则会创建失败：

antdb=# create unique index idx_t_count_unique_id on t_count (name);
ERROR:  Cannot create index whose evaluation cannot be enforced to remote nodes
antdb=#

带上分片键后再次执行：

antdb=# \d+ t_count
                                     Table "public.t_count"
 Column |     Type     | Collation | Nullable | Default | Storage  | Stats target | Description 
--------+--------------+-----------+----------+---------+----------+--------------+-------------
 id     | numeric      |           |          |         | main     |              | 
 name   | varchar2(20) |           |          |         | extended |              | 
Indexes:
    "idx_t_count_unique_id" UNIQUE, btree (id)
    "idx_t_count_id" btree (id)
    "idx_t_count_id_name" btree (id, name)
Distribute By: HASH(id)
Location Nodes: db1_4, db2_2, db3_1
antdb=# create unique index idx_t_count_unique_name on t_count (name,id);
CREATE INDEX
antdb=# \di+ idx_t_count_unique_name
                                   List of relations
 Schema |          Name           | Type  | Owner  |  Table  |    Size    | Description 
--------+-------------------------+-------+--------+---------+------------+-------------
 public | idx_t_count_unique_name | index | danghb | t_count | 8192 bytes | 
(1 row)