Oracle: working with DBMS STATS

Useful queries:

Check when statistics was gathered:
SELECT owner, table_name, last_analyzed FROM all_tables where owner='<SCHEMA_NAME>' ORDER BY last_analyzed DESC NULLS LAST; --Tables.
SELECT owner, index_name, last_analyzed FROM all_indexes where owner='<SCHEMA_NAME>' ORDER BY last_analyzed DESC NULLS LAST; -- Indexes.