Gathering Data Dictionary Statistics

Hello.  When gathering Data Dictionary Statistics do the following 2 dbms_stats commands do the same exact thing:

exec DBMS_STATS.GATHER_DATABASE_STATS (gather_sys=>TRUE);

EXEC DBMS_STATS.GATHER_DICTIONARY_STATS

My thought from past experience is that they do but wanted to confirm. 

And, after executing the above commands how can I prove that statistics were gathered for the Data Dictionary tables?  I've been reviewing some Metalink Notes and from them was selecting from dba_tables where owner='SYS' and looking at the last_analyzed column but I didn't all the last_analyzed column values to have the current date for which I ran the above commands?  There were records with the current date but not all of them?  Thanks for your help.