tencent cloud

Read-Write Separation with starocks_fdw
Download PDF
Last updated:2025-04-30 12:09:55
Read-Write Separation with starocks_fdw
Last updated: 2025-04-30 12:09:55
Download PDF
TencentDB for PostgreSQL supports the self-developed starrocks_fdw plugin, enabling you to use tables in StarRocks as foreign tables of PostgreSQL to achieve separation of hot and cold storage. This plugin is compatible with the mysql_fdw plugin. Below is an example of its usage. For more detailed parameters and usage, refer to the mysql_fdw official website. The premise of this document is that you have already deployed StarRocks and can access it. Additionally, you have purchased a TencentDB for PostgreSQL instance.
In this document, a TencentDB for PostgreSQL instance has already been purchased, and a StarRocks database has been self-built on a CVM in the same VPC. The operation process will be described for you below.
Note:
The starocks_fdw plugin currently only supports PG13 versions 13.14_r1.17 and above.

Preparing Data on StarRocks

Create a new table sr_m1:
mysql> CREATE TABLE sr_m1 (
    ->     id int not null,
    ->     str INT
    -> );
Query OK, 0 rows affected (0.02 sec)
Insert data:
mysql> insert into sr_m1(id,str)values(1,1),(2,2),(3,3);
Query OK, 3 rows affected (0.48 sec)
{'label':'insert_61cc249a-758a-11ef-a99a-5254006f765d', 'status':'VISIBLE', 'txnId':'1024'}
Check if data insertion is successful:
mysql> select * from sr_m1;
+------+------+
| id   | str  |
+------+------+
|    1 |    1 |
|    3 |    3 |
|    2 |    2 |
+------+------+
3 rows in set (0.01 sec)

Creating a Plugin on TencentDB for PostgreSQL

Create a new database and switch to it; if you already have a database, you can skip this step:
postgres=> create database am_sr;
CREATE DATABASE
postgres=> \\c am_sr
psql (14.11, server 13.14)
You are now connected to database "am_sr" as user "dbadmin".
am_sr=>
Create a plugin:
am_sr=> create extension starrocks_fdw;
CREATE EXTENSION

Creating External Services and User Mapping on TencentDB for PostgreSQL

Create an external server: Refer to the plugin parameter document for its parameters.
am_sr=> CREATE SERVER server_sr FOREIGN DATA WRAPPER starrocks_fdw OPTIONS (host '10.21.0.11', port '9030',instanceid 'ins-xxx3tfi5',access_type '2',region 'ap-guangzhou', uin '100033123456', own_uin '100033456789', vpcid 'vpc-fqxagfew', subnetid 'vpc-fqxawe23');
CREATE SERVER
Create user mapping: Assuming the user of TencentDB for PostgreSQL is dbadmin and you want to use the username root and password 123456 to connect to StarRocks, the command would be:
am_sr=> CREATE USER MAPPING for dbadmin SERVER server_sr OPTIONS (password '123456', username 'root');
CREATE USER MAPPING
You can use the following command to view the currently created external services:
am_sr-> FROM pg_foreign_server;
  srvname  | srvowner | srvfdw | srvtype | srvversion |                                                                  
                 srvoptions                                                                                    
-----------+----------+--------+---------+------------+------------------------------------------------------------------
---------------------------------------------------------------------------------------------------------------
 server_sr |    16385 |  16495 |         |            | {host=10.21.0.11,port=9030,instanceid=ins-xxx3tfi5,access_type=2
,region=ap-guangzhou,uin=100033123456,own_uin=100033456789,vpcid=vpc-fqxagfew,subnetid=vpc-fqxawe23,linkid=352}
(1 row)
You can also use the following command to view the currently established user mapping:
am_sr=> SELECT um.umid, um.srvid, fs.srvname, um.umuser, r.rolname AS usename, um.umoptions FROM pg_user_mappings um JOIN pg_foreign_server fs ON um.srvid = fs.oid JOIN pg_roles r ON um.umuser = r.oid;
 umid  | srvid |  srvname  | umuser | usename |            umoptions            
-------+-------+-----------+--------+---------+---------------------------------
 16499 | 16498 | server_sr |  16385 | dbadmin | {password=123456,username=root}
(1 row)

Creating a Foreign Table in TencentDB for PostgreSQL

Create a table:
am_sr=> CREATE TABLE sr (id INT NOT NULL,str INT) PARTITION BY RANGE (id);
CREATE TABLE
Create a foreign table:
am_sr=> CREATE foreign TABLE sr_m PARTITION OF sr FOR VALUES FROM (1) TO (10) SERVER server_sr OPTIONS (dbname 'my_database', table_name 'sr_m1');
CREATE FOREIGN TABLE
Query data:
am_sr=> select * from sr;
 id | str 
----+-----
  1 |   1
  3 |   3
  2 |   2
(3 rows)

Was this page helpful?
You can also Contact Sales or Submit a Ticket for help.
Yes
No

Feedback