SPIPlanPtr SPI_prepare_params(const char * command,
                              ParserSetupHook parserSetup,
                              void * parserSetupArg,
                              int cursorOptions)   SPI_prepare_params creates and returns an execution
   plan for the specified command, but doesn't execute the command.
   This function is equivalent to SPI_prepare_cursor,
   with the addition that the caller can specify parser hook functions
   to control the parsing of external parameter references.