> For the complete documentation index, see [llms.txt](https://docs.postgresql.tw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.postgresql.tw/server-administration/logical-replication/logical-replication-config.md).

# 29.12. Configuration Settings \#

[29.12.1. Publishers](#LOGICAL-REPLICATION-CONFIG-PUBLISHER)

[29.12.2. Subscribers](#LOGICAL-REPLICATION-CONFIG-SUBSCRIBER)

Logical replication requires several configuration options to be set. These options are relevant only on one side of the replication.

## 29.12.1. Publishers [#](#LOGICAL-REPLICATION-CONFIG-PUBLISHER)

[`wal_level`](/server-administration/runtime-config/runtime-config-wal.md#GUC-WAL-LEVEL) must be set to `logical`.

[`max_replication_slots`](/server-administration/runtime-config/runtime-config-replication.md#GUC-MAX-REPLICATION-SLOTS) must be set to at least the number of subscriptions expected to connect, plus some reserve for table synchronization.

Logical replication slots are also affected by [`idle_replication_slot_timeout`](/server-administration/runtime-config/runtime-config-replication.md#GUC-IDLE-REPLICATION-SLOT-TIMEOUT).

[`max_wal_senders`](/server-administration/runtime-config/runtime-config-replication.md#GUC-MAX-WAL-SENDERS) should be set to at least the same as `max_replication_slots`, plus the number of physical replicas that are connected at the same time.

Logical replication walsender is also affected by [`wal_sender_timeout`](/server-administration/runtime-config/runtime-config-replication.md#GUC-WAL-SENDER-TIMEOUT).

## 29.12.2. Subscribers [#](#LOGICAL-REPLICATION-CONFIG-SUBSCRIBER)

[`max_active_replication_origins`](/server-administration/runtime-config/runtime-config-replication.md#GUC-MAX-ACTIVE-REPLICATION-ORIGINS) must be set to at least the number of subscriptions that will be added to the subscriber, plus some reserve for table synchronization.

[`max_logical_replication_workers`](/server-administration/runtime-config/runtime-config-replication.md#GUC-MAX-LOGICAL-REPLICATION-WORKERS) must be set to at least the number of subscriptions (for leader apply workers), plus some reserve for the table synchronization workers and parallel apply workers.

[`max_worker_processes`](/server-administration/runtime-config/runtime-config-resource.md#GUC-MAX-WORKER-PROCESSES) may need to be adjusted to accommodate for replication workers, at least ([`max_logical_replication_workers`](/server-administration/runtime-config/runtime-config-replication.md#GUC-MAX-LOGICAL-REPLICATION-WORKERS)

* `1`). Note, some extensions and parallel queries also take worker slots from `max_worker_processes`.

[`max_sync_workers_per_subscription`](/server-administration/runtime-config/runtime-config-replication.md#GUC-MAX-SYNC-WORKERS-PER-SUBSCRIPTION) controls the amount of parallelism of the initial data copy during the subscription initialization or when new tables are added.

[`max_parallel_apply_workers_per_subscription`](/server-administration/runtime-config/runtime-config-replication.md#GUC-MAX-PARALLEL-APPLY-WORKERS-PER-SUBSCRIPTION) controls the amount of parallelism for streaming of in-progress transactions with subscription parameter `streaming = parallel`.

Logical replication workers are also affected by [`wal_receiver_timeout`](/server-administration/runtime-config/runtime-config-replication.md#GUC-WAL-RECEIVER-TIMEOUT), [`wal_receiver_status_interval`](/server-administration/runtime-config/runtime-config-replication.md#GUC-WAL-RECEIVER-STATUS-INTERVAL) and [`wal_retrieve_retry_interval`](/server-administration/runtime-config/runtime-config-replication.md#GUC-WAL-RETRIEVE-RETRY-INTERVAL).

***

原文：[PostgreSQL 18.6 Documentation](https://www.postgresql.org/docs/18/logical-replication-config.html)（英文原文，待翻譯）


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