Added to Oracle articles: some new info (difference between NVL and COALESCE, etc.), fixed errors, ... To Overview of group, analytical, and hierarchical queries added new functions (FIRST, LAST, NTILE).
Added to Oracle articles: some new info (difference between NVL and COALESCE, etc.), fixed errors, ... To Overview of group, analytical, and hierarchical queries added new functions (FIRST, LAST, NTILE).