PostgreSQL 10.0 has been released in late 2017 and is the first version that follows the new numbering scheme introduced by the PostgreSQL community. From now on, the way major releases are done will change and therefore, the next major version after PostgreSQL 10.0 will not be 10.1 but PostgreSQL 11. Versions 10.1 and 10.2 are merely service releases and will only contain bug fixes.
What is new in PostgreSQL 10.0?
Understanding new database administration functions
PostgreSQL 10.0 has many new features that can help the administrator reduce work and make systems more robust.
One of these features that makes life easier for administrators is related to additional information in pg_stat_activity.
Using additional information in pg_stat_activity
Before PostgreSQL 10.0, pg_stat_activity only contained information about normal backend processes serving end users (connections). However, this has changed. Since PostgreSQL 10.0, a lot more information is exposed. It is possible to figure out what these other system processes are doing.
The following listing shows the content of pg_stat_activity on an idle database instance:
test=# \x Expanded display is on.
test=# SELECT pid, wait_event_type, wait_event, backend_type FROM pg_stat_activity ;
-[ RECORD 1 ]---+-------------------- pid | 12159 wait_event_type | Activity wait_event | AutoVacuumMain backend_type | autovacuum launcher -[ RECORD 2 ]---+-------------------- pid | 12161 wait_event_type | Activity wait_event | LogicalLauncherMain backend_type | background worker -[ RECORD 3 ]---+-------------------- pid | 12628 wait_event_type | wait_event | backend_type | client backend -[ RECORD 4 ]---+-------------------- pid | 12156 wait_event_type | Activity wait_event | BgWriterMain backend_type | background writer -[ RECORD 5 ]---+-------------------- pid | 12155 wait_event_type | Activity wait_event | CheckpointerMain backend_type | checkpointer -[ RECORD 6 ]---+-------------------- pid | 12157 wait_event_type | Activity wait_event | WalWriterMain backend_type | walwriter
What you see here is that every server process is listed. It will allow you to gain some insights into what is happening the server.