SQLite

** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
** to signal that the function will always return the same result given
** the same inputs within a single SQL statement.  Most SQL functions are
** deterministic.  The built-in [random()] SQL function is an example of a
** function that is not deterministic.  The SQLite query planner is able to
** perform additional optimizations on deterministic functions, so use
** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
**
** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
** flag, which if present prevents the function from being invoked from
** within VIEWs or TRIGGERs.  For security reasons, the [SQLITE_DIRECTONLY]
** flag is recommended for any application-defined SQL function that has
** side-effects.
**
** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
** function can gain access to this pointer using [sqlite3_user_data()].)^
**
** ^The sixth, seventh and eighth parameters passed to the three
** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
** pointers to C-language functions that implement the SQL function or

** [sqlite3_create_function_v2()].
**
** The SQLITE_DETERMINISTIC flag means that the new function will always
** maps the same inputs into the same output.  The abs() function is
** deterministic, for example, but randomblob() is not.
**
** The SQLITE_DIRECTONLY flag means that the function may only be invoked
** from top-level SQL, and cannot be used in VIEWs or TRIGGERs.  This is
** a security feature which is recommended for all 
** [application-defined SQL functions] that have side-effects.  This flag 
** prevents an attacker from adding triggers and views to a schema then 
** tricking a high-privilege application into causing unintended side-effects
** while performing ordinary queries.
**
** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
** Specifying this flag makes no difference for scalar or aggregate user
** functions. However, if it is not specified for a user-defined window
** function, then any sub-types belonging to arguments passed to the window
** function may be discarded before the window function is called (i.e.