int sqlite3_vtab_config(sqlite3*, int op, ...);
This function may be called by either the xConnect or xCreate method of a virtual table implementation to configure various facets of the virtual table interface.
If this interface is invoked outside the context of an xConnect or xCreate virtual table method then the behavior is undefined.
In the call sqlite3_vtab_config(D,C,...) the D parameter is the database connection in which the virtual table is being created and which is passed in as the first argument to the xConnect or xCreate method that is invoking sqlite3_vtab_config(). The C parameter is one of the virtual table configuration options. The presence and meaning of parameters after C depend on which virtual table configuration option is used.
See also lists of Objects, Constants, and Functions.
SQLite is in the Public Domain.
https://sqlite.org/c3ref/vtab_config.html