发布功能

create_publisher

在每个数据库中，您可以创建多个出版物，以便将更改发布到不同的订阅者。

Arguments:

    publisher_name               The Unique name of publisher.
    for table                    To publish single/list of tables
    for all table                To publish all tables, along with future tables.
    for all tables in schema     To publish all tables in schema, along wth future tables.

Usage:
    exampledb=> create publication my_publication for all tables ;
    CREATE PUBLICATION

list_publisher

列出每个数据库中运行的出版物数量。

Usage:
   exampledb=# select * from pg_publication;
   oid  |    pubname     | pubowner | puballtables | pubinsert | pubupdate | pubdelete | pubtruncate
   -------+----------------+----------+--------------+-----------+-----------+-----------+-------------
   16401 | my_publication |       10 | t            | t         | t         | t         | t

alter_publisher

修改出版物的定义。

Syntax:
ALTER PUBLICATION name ADD publication_object [, ...]
ALTER PUBLICATION name SET publication_object [, ...]
ALTER PUBLICATION name DROP publication_object [, ...]
ALTER PUBLICATION name SET ( publication_parameter [= value] [, ... ] )
ALTER PUBLICATION name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER PUBLICATION name RENAME TO new_name


 Usage:
    exampledb=# ALTER PUBLICATION my_publication RENAME TO my_publication_new;
    ALTER PUBLICATION

drop_publisher

删除/移除不再使用的出版物。

Usage:
    exampledb=# drop publication my_publication_new;
    DROP PUBLICATION

请考虑以下前提条件：

1. 配置外部（发布者） PostgreSQL wal_level=logical。
2. 每个被选中用于复制的表都需要包含 一个主键，或者 REPLICA IDENTITY 一组。
3. 您的外部（发布商） PostgreSQL 需要有一个 拥有 PostgreSQL 权限 REPLICATION 的复制用户，该用户需要拥有数据库的SELECT和USAGE权限以及REPLICATION权限。
4. 您复制的 PostgreSQL 需要启用 TLS/SSL。
5. 如果启用了行级安全，则向外部（发布者） PostgreSQL 复制用户授予 BYPASSRLS 权限。

PostgreSQL 文档中概述了逻辑复制的一些固有限制和约束。 在决定逻辑复制是否适合您的使用案例之前，请先阅读这些内容。

用户功能

create_subscription

Arguments:
    subscription_name   Unique name to create the subscription channel with
    host_ip             Publisher hostname or public IP address
    port                Port number publisher is running on
    username            `admin` user created on the publisher
    password            Password of the `admin` user on the publisher
    db_name             The name of the database to be replicated
    publisher_name      The name of publisher channel on the publisher

Usage:
    exampledb=> SELECT create_subscription('subs1','130.215.223.184','5432','password','admin','exampledb','my_publication');

delete_subscription

Arguments:
    subscription_name   Name the subscription channel to delete
    db_name             The name of the replicated database

Usage:
exampledb=> SELECT delete_subscription('subs1', 'exampledb');

list_subscriptions

Arguments:
    None

Usage:
    exampledb=> SELECT * FROM list_subscriptions();

disable_subscription

Arguments:
    subscription_name   Name the subscription channel to disable
    db_name             The name of the replicated database

Usage:
    exampledb=> SELECT disable_subscription('subs1','exampledb');

enable_subscription

Arguments:
    subscription_name   Name the subscription channel to enable
    db_name             The name of the replicated database

Usage:
    exampledb=> SELECT enable_subscription('subs1','exampledb');

subscription_slot_none

此函数用于将订阅的插槽名称设置为“无”。 删除订阅时需要这样做，这样远程复制插槽就不会被删除，或者不存在或从未存在过。

Arguments:
    subscription_name   Name the subscription channel to alter
    db_name             The name of the replicated database

Usage:
    exampledb=> SELECT subscription_slot_none('subs1','exampledb');

refresh_subscription

该函数用于在发布者进行更改（如添加或删除表）后刷新订阅者的订阅。

Arguments:
    subscription_name   Name the subscription channel to refresh
    db_name             The name of the replicated database

Usage:
    exampledb=> SELECT refresh_subscription('subs1','exampledb');