DETERMINISTIC characteristic

Applies to ❌ Open Source Edition   ✅ Express Edition   ✅ Professional Edition   ✅ Enterprise Edition

Some dialects require the explicit specification of a few characteristics of a function. The DETERMINISTIC characteristic can be used to tell the database that contents of a function are guaranteed by the user to be "deterministic" (or "IMMUTABLE" in PostgreSQL), meaning that the result of a function is purely defined by the function arguments (never by data or session values or the current time or random number generators, etc.) such that a function expression can be replaced by the result value at the call site. Such a function is also said to be side-effect free, and pure. Some dialects (e.g. Oracle) allow for using DETERMINISTIC functions in function based indexes.

If DETERMINISTIC is not supported by your dialect, you can still specify it, and jOOQ will simply ignore it in generated SQL.