Dear Adrian, Sorry, there is an error in the email just replied, the version of PostgreSQL is wrong. PostgreSQL 8.4 → PostgreSQL 8.2
At 2022-08-19 12:42:54, "gzh" <gzhco...@126.com> wrote: Dear Adrian, I appreciate your reply. Your reply gave me a new idea, it should not be the problem that the lower() function causes the unique index to fail. I checked the postgresql.conf file and found that shared_buffers, work_mem and maintenance_work_mem are default value, but in the postgresql.conf file of PostgreSQL 8.4, the value of these parameters are very large. When I changed the value of these parameters to a larger value, the problem solved.
