Understanding the pgactive schema - Amazon Relational Database Service
pgactive_nodespgactive_connectionWorking with replication sets

Understanding the pgactive schema

The pgactive schema manages active-active replication in RDS for PostgreSQL. This schema contains tables that store replication configuration and status information.

Note

The pgactive schema is evolving and subject to change. Don't modify the data in these tables directly.

The key tables in the pgactive schema include:

  • pgactive_nodes – Stores information about nodes in the active-active replication group.

  • pgactive_connections – Stores connection details for each node.

pgactive_nodes

The pgactive_nodes stores information about the nodes participating in the active-active replication group.

Column

Type

Collation

Nullable

Default
node_sysid text – not null –
node_timeline oid – not null –
node_dboid oid – not null –
node_status char – not null –
node_name text – not null –
node_dsn text – not null –
node_init_from_dsn text – not null –
node_read_only boolean – – false
node_seq_id smallint – not null –
node_sysid

Unique ID for a node, generated during pgactive_create_group or pgactive_join_group

node_status

Readiness of the node:

  • b - beginning setup

  • i - initializing

  • c - catchup

  • o - creating outbound slots

  • r - ready

  • k - killed

Note

This column doesn't indicate if a node is connected or disconnected.

node_name

User-provided unique node name.

node_dsn

Connection string or user mapping name

node_init_from_dsn

DSN from which this node was created.

pgactive_connection

The pgactive_connections stores connection details for each node.

Column Type Collation Nullable Default
conn_sysid text none not null none
conn_timeline oid none not null none
conn_dboid oid none not null none
conn_dsn text none not null none
conn_apply_delay integer none none none
conn_replication_sets text none none none
conn_sysid

Node identifier for the node this entry refers to.

conn_dsn

Same as pgactive.pgactive_nodes node_dsn.

conn_apply_delay

If set, milliseconds to wait before applying each transaction from the remote node. Mainly for debugging. If null, the global default applies.

Working with replication sets

Replication sets determine which tables to include or exclude from replication operations. By default, all tables are replicated unless you specify otherwise using the following functions:

  • pgactive_exclude_table_replication_set() - Excludes specified tables from replication

  • pgactive_include_table_replication_set() - Includes specified tables in replication

Note

Before you configure replication sets, consider the following:

  • You can configure table inclusion or exclusion only after running pgactive_create_group() but before pgactive_join_group().

  • After you use pgactive_exclude_table_replication_set(), you can't use pgactive_include_table_replication_set().

  • After you use pgactive_include_table_replication_set(), you can't use pgactive_exclude_table_replication_set().

The system handles newly created tables differently based on your initial configuration:

  • If you excluded tables: Any new tables created after pgactive_join_group() are automatically included in replication

  • If you included tables: Any new tables created after pgactive_join_group() are automatically excluded from replication.

To view the replication set configuration for a specific table, use the pgactive.pgactive_get_table_replication_sets() function.