SQL> conn xxx/xxx@xxx
Connected.
SQL> select version from v$instance;

VERSION
-----------------
10.2.0.1.0

SQL> create table test (a number not null);

Table created.

SQL> insert into test select rownum from dba_users;

34 rows created.

SQL> commit;

Commit complete.

SQL> create materialized view test_cnt 
  2  refresh complete on demand
  3  enable query rewrite
  4  as select count(*) from test;

Materialized view created.

SQL> exec dbms_stats.gather_table_stats(user, 'test')

PL/SQL procedure successfully completed.

SQL> exec dbms_stats.gather_table_stats(user, 'test_cnt')

PL/SQL procedure successfully completed.

SQL> alter session set events '10046 trace name context forever, level 12';

Session altered.

SQL> exec dbms_mview.refresh('test_cnt', atomic_refresh=>true)

PL/SQL procedure successfully completed.

SQL> exec dbms_mview.refresh('test_cnt', atomic_refresh=>false)

PL/SQL procedure successfully completed.

PARSING IN CURSOR #28 len=66 dep=0 uid=60 oct=47 lid=60 tim=2665224989 hv=1147574116 ad='251c39cc'
BEGIN dbms_mview.refresh('test_cnt', atomic_refresh=>true); END;
END OF STMT

PARSING IN CURSOR #40 len=53 dep=1 uid=60 oct=7 lid=60 tim=2666008092 hv=2672436950 ad='219370d4'
/* MV_REFRESH (DEL) */ delete from "GINTS"."TEST_CNT"
END OF STMT

PARSING IN CURSOR #40 len=129 dep=1 uid=60 oct=2 lid=60 tim=2666025488 hv=4050016697 ad='2a4b42c0'
/* MV_REFRESH (INS) */INSERT /*+ BYPASS_RECURSIVE_CHECK */ INTO "GINTS"."TEST_CNT"("COUNT(*)") SELECT COUNT(*) FROM "TEST" "TEST"
END OF STMT

PARSING IN CURSOR #41 len=67 dep=0 uid=60 oct=47 lid=60 tim=2674847160 hv=1029517213 ad='25117ea4'
BEGIN dbms_mview.refresh('test_cnt', atomic_refresh=>false); END;
END OF STMT

PARSING IN CURSOR #50 len=75 dep=1 uid=60 oct=85 lid=60 tim=2675070150 hv=2256023461 ad='25d986a4'
/* MV_REFRESH (DEL) */ truncate table "GINTS"."TEST_CNT" purge snapshot log
END OF STMT

PARSING IN CURSOR #50 len=137 dep=1 uid=60 oct=2 lid=60 tim=2675482059 hv=131783386 ad='218a6704'
/* MV_REFRESH (INS) */INSERT /*+ BYPASS_RECURSIVE_CHECK APPEND  */ INTO "GINTS"."TEST_CNT"("COUNT(*)") SELECT COUNT(*) FROM "TEST" "TEST"
END OF STMT