Mingzuo Shen <mzshen@xxxxxxxxx> writes: > when I say psql shows nothing, > I really mean "nothing". > No error messages. > Of course if I create a new db, psql -l shows my > new db. > psql -l > List of databases > Name | Owner | Encoding > --------+----------+----------- > testdb | postgres | SQL_ASCII > (1 row) This sounds like transaction XID wraparound in pg_database. What vacuuming policy have you been following? It'd possibly work to do "vacuum pg_database" to fix it, but if so you've got other problems ... regards, tom lane
