Hello, I'm working on a high availability project for PG(v9.6). Suppose I have a priamry-standby setup, I need to do promote once primary is down, but only when standby is as new as primary (before it is down). Therefore, I need a way to know the wal replay location on standby. I tried to set a hot standby, but it failed to run `pg_current_xlog_location()` on it; I also tried `pg_xlogdump` on standby, but it has following cavets: - hard to identify latest used wal segment, since there are some renamed reservations - sometimes `pg_xlogdump` will raise errors like: "pg_xlogdump: FATAL: error in WAL record at 0/9F88F0F8: record with incorrect prev- link 2020/20202020 at 0/9F88F130" So I want to know what is the correct way to do it. Thank you in advance!
