Vacuum and state_change

Hi

Had a couple of processes blocking the vacuum so I terminated them using
select pg_terminate_backend(pid);

Running the following
select distinct pid, backend_start, query_start, state_change, state, query from pg_catalog.pg_stat_activity order by 1;
pid | backend_start | query_start | state_change | state | query
-------+-------------------------------+-------------------------------+-------------------------------+--------+--------------------------------------------------------------------------------------------------------------------------
10677 | 2017-06-09 10:25:49.189848-05 | 2017-06-09 10:33:43.598805-05 | 2017-06-09 10:33:43.599091-05 | idle | SELECT 1
11096 | 2017-06-09 10:27:03.686588-05 | 2017-06-09 10:33:56.28736-05 | 2017-06-09 10:33:56.287364-05 | active | select distinct pid, backend_start, query_start, state_change, state, query from pg_catalog.pg_stat_activity order by 1;
13277 | 2017-06-09 07:48:49.506686-05 | 2017-06-09 07:48:52.887185-05 | 2017-06-09 07:48:52.887188-05 | active | autovacuum: VACUUM csischema.tf_purchased_badge
13484 | 2017-06-09 10:31:54.127672-05 | 2017-06-09 10:33:47.137938-05 | 2017-06-09 10:33:47.138226-05 | idle | SELECT 1
16886 | 2017-06-09 07:56:49.033893-05 | 2017-06-09 07:56:49.078369-05 | 2017-06-09 07:56:49.078371-05 | active | autovacuum: VACUUM csischema.tf_purchases_person
25387 | 2017-06-09 05:32:08.079397-05 | 2017-06-09 05:32:08.385728-05 | 2017-06-09 05:32:08.385731-05 | active | autovacuum: VACUUM csischema.tf_demographic_response_person
37465 | 2017-06-09 08:50:58.992002-05 | 2017-06-09 08:51:21.506829-05 | 2017-06-09 08:51:21.506831-05 | active | autovacuum: VACUUM csischema.tf_transaction_item_person

I did notice that state_change did not change one bit

Does that mean that something is not quite right with the vacuums ?

Thank you
Armand