创建列存储引擎插件

使用列存储表之前，需要创建extension，插件创建完成之后，可以在 pg_extension 系统表中看到新增的插件条目

teledb=# CREATE EXTENSION pax;
CREATE EXTENSION
teledb=# select * from pg_extension;
   extname    | extowner | extnamespace | extrelocatable | extversion | extconfig | extcondition 
--------------+----------+--------------+----------------+------------+-----------+--------------
 plpgsql      |       10 |           11 | f              | 1.0        |           | 
 teledbx_core |       10 |         2200 | t              | 1.0        |           | 
 pax          |       10 |           11 | f              | 1.0        |           | 
(3 rows)

teledb=# \dx
                    List of installed extensions
     Name     | Version |   Schema   |         Description        
--------------+---------+------------+------------------------------
 pax          | 1.0     | pg_catalog | pax access method
 plpgsql      | 1.0     | pg_catalog | PL/pgSQL procedural language
 teledbx_core | 1.0     | public     | core module of teledbx
(3 rows)

查看系统表列存储引擎新增条目

创建列存储插件引擎后，在pg_am 系统表中看到新增的表访问方式，在 pg_namespace 系统表中看到新增的辅助表命名空间

teledb=# select oid, * from pg_am;
  oid  | amname |           amhandler            | amtype 
-------+--------+--------------------------------+--------
   403 | btree  | bthandler                      | i
   405 | hash   | hashhandler                    | i
   783 | gist   | gisthandler                    | i
  2742 | gin    | ginhandler                     | i
  4000 | spgist | spghandler                     | i
  3580 | brin   | brinhandler                    | i
     2 | heap   | heap_tableam_handler           | t
 16396 | pax    | pg_ext_aux.pax_tableam_handler | t
(8 rows)

teledb=# select oid, * from pg_namespace;
  oid  |      nspname       | nspowner |                  nspacl                 
-------+--------------------+----------+-------------------------------------------
    99 | pg_toast           |       10 | 
  5500 | pg_oracle          |       10 | 
  7094 | pg_ext_aux         |       10 | 
 11952 | pg_temp_1          |       10 | 
 11953 | pg_toast_temp_1    |       10 | 
    11 | pg_catalog         |       10 | {teledb=UC/teledb,=U/teledb}
  2200 | public             |       10 | {teledb=UC/teledb,=UC/teledb}
 13117 | information_schema |       10 | {teledb=UC/teledb,=U/teledb}
(8 rows)

删除列存储引擎插件

teledb=# DROP EXTENSION pax;
DROP EXTENSION
teledb=# \dx
                    List of installed extensions
     Name     | Version |   Schema   |         Description        
--------------+---------+------------+------------------------------
plpgsql      | 1.0     | pg_catalog | PL/pgSQL procedural language
 teledbx_core | 1.0     | public     | core module of teledbx
(2 rows)