The following bug has been logged on the website:
Bug reference: 16088
Logged by: Jess Sturgeon
Email address: jsturgeon@novetta.com
PostgreSQL version: 12.0
Operating system: RHEL 7.7
Description:
If you run this command multiple times:
ALTER TABLE myschema.mytable ADD IF NOT EXISTS mycolumn uuid REFERENCES
myschema.mytable2(userid);
It adds the column once, but adds a duplicate FOREIGN KEY each time. I had
over 59 keys while debugging my schema definition :)
This happens in PG11.5 and PG12 for me, both on RHEL 7.7
