I think we can consider using AFTER triggers to meet the needs of the subject in PG.

suppose you have a table foo whose definition and available data are as follows:

postgres=-sharp \d+ foo;
                                    Table "public.foo"
 Column |  Type   | Collation | Nullable | Default | Storage  | Stats target | Description 
--------+---------+-----------+----------+---------+----------+--------------+-------------
 id     | integer |           | not null |         | plain    |              | 
 name   | text    |           |          |         | extended |              | 
Indexes:
    "idx_foo" PRIMARY KEY, btree (id)
    
postgres=-sharp SELECT * FROM foo;
 id |      name       
----+-----------------
  1 | Paul McCartney
  2 | John Lennon
  3 | George Harrison
  4 | Ringo Starr
(4 rows)

the following steps create a materialized view and create an automatic refresh trigger associated with it

1. create a materialized view

   postgres=-sharp CREATE MATERIALIZED VIEW mvfoo AS SELECT * FROM foo;

2. create a trigger function to refresh the materialized view

   postgres=-sharp CREATE OR REPLACE FUNCTION tri_foo_func() RETURNS TRIGGER AS $$ BEGIN REFRESH MATERIALIZED VIEW mvfoo; RETURN NULL; END; $$ LANGUAGE plpgsql;

   since we are going to create an AFTER trigger, the function returns NULL

3. create the AFTER trigger itself

   CREATE TRIGGER tri_foo AFTER INSERT OR UPDATE OR DELETE ON foo FOR EACH STATEMENT EXECUTE PROCEDURE tri_foo_func();

   The trigger is triggered by

   INSERT, UPDATE, DELETE events

then you can do a simple check

1. query the materialized view when no changes have been made to the table

   postgres=-sharp SELECT * FROM mvfoo;
    id |      name       
   ----+-----------------
     1 | Paul McCartney
     2 | John Lennon
     3 | George Harrison
     4 | Ringo Starr
   (4 rows)

2. query the materialized view after updating the table (in this case, the INSERT operation).

   postgres=-sharp INSERT INTO foo VALUES (5, 'Brain Epstein');
   INSERT 0 1
   postgres=-sharp SELECT * FROM mvfoo;
    id |      name       
   ----+-----------------
     1 | Paul McCartney
     2 | John Lennon
     3 | George Harrison
     4 | Ringo Starr
     5 | Brain Epstein
   (5 rows)

   it can be seen that this set of trigger-based materialized view automatic refresh mechanism has taken effect

   however, it must be emphasized that using triggers is harmful to the update performance of the original table , please use it carefully in combination with specific application scenarios.