12cR2 manual gather stats

1. Any difference between the below 2 manual execution?

I believe both will gather stats for both stale and empty statistics (and based on prefs setting).

-> exec DBMS_AUTO_TASK_IMMEDIATE.GATHER_OPTIMIZER_STATS;

-> exec DBMS_STATS.GATHER_DATABASE_STATS (options => 'GATHER AUTO');

Asking this as i notice that option one will take longer to complete.

2. Does the above include gathering dictionary stats and fixed objects with stale and empty stats?

I believe so due to AUTOSTATS_TARGET=AUTO. But need confirmation on this.

Output of get_prefs:

Automatic Stats Gathering Job - Parameters

==========================================

AUTOSTATS_TARGET: AUTO

CASCADE: DBMS_STATS.AUTO_CASCADE