Traditionally, statistics were gathered during maintenance windows. 19c gathers them "on-the-fly" during conventional DML operations (Insert/Update/Merge), ensuring the optimizer has up-to-date information for better execution plans. SQL Quarantine:
Developers can now use the DISTINCT keyword within the LISTAGG function to remove duplicate values from a concatenated string, a common request in previous versions. Key PDF Documentation for Oracle 19c oracle sql 19c pdf new
Unlike older Oracle versions, 19c PDFs are bundled into a single ZIP on OTN. Instead, you access them via the official Oracle Help Center: oracle sql 19c pdf new