PeerDB’s Postgres connector can detect schema changes in the source tables. For Postgres, BigQuery and Snowflake destinations, it can propagate some of these changes to the corresponding destination tables as well. The way each schema change is handled is documented below:

Schema Change TypeBehaviour
Adding a new column (ALTER TABLE ADD COLUMN ...)Propagated automatically, all rows after the change will have all columns filled
Adding a new column with a default value (ALTER TABLE ADD COLUMN ... DEFAULT ...)Propagated automatically, all rows after the change will have all columns filled but existing rows will not show the DEFAULT value without a full table refresh
Dropping an existing column (ALTER TABLE DROP COLUMN ...)Detected, but not propagated. All rows after the change will have NULL for the dropped columns
Streaming Query Replication of PostgreSQL To SnowflakeReplicating partitioned tables