A message from kapa.ai

Based on the information provided, it seems like there might be an issue with the data normalization process. The error message indicates that the '_airbyte_unique_key' column is missing while processing the query, even though you've confirmed that the column is present in the table. The '_airbyte_unique_key' is a hash of the primary key field, with some additional logic to handle records where this is undefined [source](https://airbyte.com/tutorials/incremental-data-synchronization). Here are a few things you could try: 1. Check the Data Types: Ensure that the data types of the '_airbyte_unique_key' column in your source (PostgreSQL) and destination (ClickHouse) are compatible. 2. Check the Permissions: Ensure that the user you're using to connect to your ClickHouse destination has the necessary permissions to read the '_airbyte_unique_key' column [source](https://docs.airbyte.com/integrations/destinations/clickhouse). 3. Recreate the Connection: As per a [forum post](https://discuss.airbyte.io/t/4483), a user facing a similar issue was able to resolve it by deleting the connection, dropping all Airbyte tables, and recreating the connection. If you're still facing issues, I recommend checking out the [Airbyte troubleshooting guide](https://docs.airbyte.com/integrations/sources/postgres/postgres-troubleshooting) for more help.