On Thu, May 30, 2024 at 11:59 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
vaibhave postgres <postgresvaibhave@gmail.com> writes: > 1. Create a database which has circular foreign key dependencies. (or use > the sql script which I have shared), restore the pre-data section first. > 2. pg_dump -Fc *--section=post-data* > 3. pg_restore --jobs > 1
> pg_restore fails to record the dependency between the foreign keys and > tries to process them in parallel (see the attached log file for details)
The reason this works in other cases is that pg_restore recognizes that two ADD CONSTRAINT steps shouldn't be run concurrently when they have dependencies on the same table(s). However, when you use --section=post-data to create the dump file, there are no entries for the tables.
So this seems like a "don't do that" case. You could get the results you want by using --schema-only at dump time and then using --section=post-data as a pg_restore switch. (That'd also avoid the need to make two separate dump files.)
Possibly we should add something to the docs about this.
