Examples

Create a Ustore table.

Run the CREATE TABLE statement to create a Ustore table.

gaussdb=# CREATE TABLE ustore_table(a INT PRIMARY KEY, b CHAR (20)) WITH (STORAGE_TYPE=USTORE);
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "ustore_table_pkey" for table "ustore_table"
CREATE TABLE
gaussdb=# \d+ ustore_table
Table "public.ustore_table"
Column |     Type      | Modifiers | Storage  | Stats target | Description
--------+---------------+-----------+----------+--------------+-------------
a      | integer       | not null  | plain    |              |
b      | character(20) |           | extended |              |
Indexes:
"ustore_table_pkey" PRIMARY KEY, ubtree (a) WITH (storage_type=USTORE) TABLESPACE pg_default
Has OIDs: no
Options: orientation=row, storage_type=ustore, compression=no

Create an index for a Ustore table.

Currently, Ustore supports only multi-version B-tree indexes. In some scenarios, to distinguish them from Astore B-tree indexes, a multi-version B-tree index of the Ustore table is also called a Ustore B-tree or UB-tree. For details about UB-tree, see Index. You can run the CREATE INDEX statement to create a UB-tree index for the "a" attribute of a Ustore table.

If no index type is specified for a Ustore table, a UB-tree index is created by default.

gaussdb=# CREATE INDEX UB-tree_index ON ustore_table(a);
CREATE INDEX
gaussdb=# \d+ ustore_table
Table "public.ustore_table"
Column |     Type      | Modifiers | Storage  | Stats target | Description
--------+---------------+-----------+----------+--------------+-------------
a      | integer       | not null  | plain    |              |
b      | character(20) |           | extended |              |
Indexes:
"ustore_table_pkey" PRIMARY KEY, ubtree (a) WITH (storage_type=USTORE) TABLESPACE pg_default
"ubtree_index" ubtree (a) WITH (storage_type=USTORE) TABLESPACE pg_default
Has OIDs: no
Options: orientation=row, storage_type=ustore, compression=no