Jorel Casal <jca...@ixl.com> writes: > During a Patroni leader switchover, we had a situation where a unique index > stopped "working", the index did not have records > that were in fact in the table and the table had duplicate records which > should have been prevented by said unique index.
If the index was on a string type (text/varchar), the most likely explanation is a switch to a different OS version with inconsistent collation rules. See https://wiki.postgresql.org/wiki/Locale_data_changes regards, tom lane
