使用JPA查询Postgres复制状态

Question

I am trying to query the replication status of the underlying database using the query:

em.createNativeQuery("SELECT application_name, backend_start, state, cast(write_lag as text) FROM pg_stat_replication;").getResultList();

Unfortunately, all columns except application_name return null. Even if I only run

 em.createNativeQuery("SELECT backend_start FROM pg_stat_replication;").getResultList();

I get a null result. If I run the same query in the postgres command-line client, I get a meaningful result:

dbname=# select backend_start from pg_stat_replication;
         backend_start         
-------------------------------
 2018-10-16 09:01:58.262578+02
(1 row)

I am using spring-boot 1.2.6 with hibernate, and postgresql 10.5.

What can I do so I get the results for this query?

Answer 1

Just after posting, I realised I user different users in the CLI and from java. Apparently, the user needs to be superuser or have the pg_read_all_stats default role. Like this:

GRANT pg_read_all_stats TO user;