A truly "new" PDF will document these features. If you download a PDF from 2019, you will miss these critical enhancements.
Oracle Database 19c is the long-term release in the Oracle 12c/18c/19c family and includes numerous SQL-level improvements focused on performance, manageability, and developer productivity. This article summarizes the key SQL features and enhancements you should know and points to how to get a PDF reference.
For Oracle Database 19c, several official and expert resources provide detailed documentation on new features, SQL improvements, and architecture in PDF format.
The latter explicitly refers to documentation that covers features introduced in the latest patchsets (e.g., 19.10 through 19.22). A generic "19c PDF" might be from the initial 2019 release. Always check the copyright page for the last updated date.
Someone had scribbled in the margins: "Use SQL_MACROS. Replace CONNECT BY with recursive WITH. Trust JSON_TABLE."
Unlike older Oracle versions, 19c PDFs are bundled into a single ZIP on OTN. Instead, you access them via the official Oracle Help Center: