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Arcyria never changes your database’s settings, roles, publications, or tables. It checks the source and gives you SQL to run yourself. The only thing it creates is the pipeline’s own replication slot, and only after you confirm.

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Requirements

  • PostgreSQL 11 or newer (13+ for WAL status in slot health).
  • wal_level = logical.
  • A connection user with the REPLICATION attribute (RDS and Aurora: the rds_replication role).
  • A direct connection to the primary. Transaction poolers such as Supavisor, PgBouncer, or port 6543 do not support replication. Standbys work only on PostgreSQL 16+.
  • A free replication slot (max_replication_slots).
  • Every CDC table has a primary key, or you choose a unique index. See Tables without a primary key.

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Set up

  1. Open the pipeline, then Source → Change data capture.
  2. Choose the publication scope: Selected tables (recommended) or All tables (needs a superuser).
  3. Click Run checks. Each failed check shows the fix.
  4. Run the Setup SQL on your database as an administrator. It creates the replication user and the publication.
  5. Update the pipeline’s source connection to use that user, then click Run checks again.
  6. When every check passes, click Enable CDC and confirm. Arcyria creates the slot, and the source starts keeping WAL for it.
  7. In the stream table, set Sync mode to CDC, open Options, and click Save stream settings.

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Provider notes

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Supabase

  • Use the Direct connection string from Connect, not the pooler.
  • The direct connection uses IPv6 unless your project has the IPv4 add-on.
  • Create the replication role with CREATE ROLE ... WITH REPLICATION, as in the setup SQL.

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Amazon RDS for PostgreSQL

  • Set rds.logical_replication = 1 in the instance’s DB parameter group, then reboot.
  • Grant the replication user rds_replication.

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Amazon Aurora PostgreSQL

  • Set rds.logical_replication = 1 in a custom DB cluster parameter group, then reboot the writer instance.
  • Connect Arcyria to the cluster (writer) endpoint.
  • Setting this up requires rds_superuser.

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Google Cloud SQL for PostgreSQL

  • Set the cloudsql.logical_decoding flag to on, then restart the instance.
  • Create the user with CREATE USER ... WITH REPLICATION IN ROLE cloudsqlsuperuser, or run ALTER USER ... WITH REPLICATION.

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Self-managed PostgreSQL

  • Set wal_level = logical in postgresql.conf, then restart.
  • Allow replication connections for the user in pg_hba.conf.

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Stream options

Open Options on a CDC stream:
  • Deletes
    • Hard delete (default) removes the row from the destination.
    • Soft delete sets _arcyria_deleted = true (the column must exist) and clears it if the row returns.
    • Skip deletes ignores them.
    Deletes apply only where the destination key is the source key. See Delete handling.
  • Truncate
    • Stop and ask (default) fails the run until you choose another option.
    • Ignore with a warning keeps destination rows.
    • Truncate the destination empties destinations whose key is the source key, then applies the changes that followed the truncate.
    A captured truncate is never passed over silently.
  • Merge key: shown when the table has no primary key.
  • Re-snapshot stream: reloads this stream from a fresh first load.
  • Accept source schema: after a schema change, adopts the current source columns. See Schema changes.

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Tables without a primary key

PostgreSQL can only publish UPDATE and DELETE for a table that has a replica identity. A published table without a primary key and with the default identity makes UPDATE and DELETE fail on your database. Run checks flags these tables and gives you one of two statements to run:
Then set the stream’s Merge key to the index columns, and give the destination table the same key.

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Schema changes

Choose how CDC handles source DDL under Change data capture → Source schema changes:
  • Fail the run (default): any added, dropped, or retyped source column stops CDC runs before data moves. The run page lists the changed columns. Update your model or destination, then use Accept source schema on the stream.
  • Add new columns: new source columns are accepted. If a model outputs one that the destination lacks, Arcyria adds it as a nullable column (PostgreSQL and MySQL destinations). Dropped or retyped columns still fail.
Arcyria never drops or retypes destination columns.

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Slot health and alerts

The CDC panel shows:
  • lag and the WAL the slot holds;
  • the last confirmed position;
  • the WAL status;
  • the time of the last check.
The warning threshold defaults to 1 GiB and the critical threshold to 10 GiB. Change both in the panel. Two settings keep the slot healthy:
  • Run CDC often. The slot only advances when Arcyria consumes it.
  • Optional heartbeat. If a database is quiet but busy elsewhere, include the heartbeat helper in the setup SQL. It needs pg_cron or another scheduler.

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Turn CDC off

Switch the streams to another sync mode, save, then click Disable CDC. Arcyria drops the slot, and the source stops keeping WAL for it. Deleting the pipeline also drops the slot.