docs/content/stable/yugabyte-voyager/voyager-troubleshoot.md
When running the assess migration or export schema commands on a PostgreSQL 17.0–17.2 source database, you may see the following error:
pg_dump: error: query failed: ERROR: invalid constraint type "n"
pg_dump: detail: Query was: EXECUTE getDomainConstraints('16452')
This error occurs when using pg_dump version 17.6 with a PostgreSQL source database running versions 17.0, 17.1, or 17.2 that contains domain objects with NOT NULL constraints.
A bug in PostgreSQL versions 17.0-17.2 causes pg_get_constraintdef() to not interpret NOT NULL domain constraints, leading to failure in pg_dump version 17.6 when using this function to fetch schema information.
Use an older version of pg_dump.
Use pg_dump version 17.5 or earlier as follows:
Upgrade PostgreSQL.
Upgrade your PostgreSQL source database to version 17.3 or later, as the bug has been fixed in these releases.