SPI_finish — disconnect a C function from the SPI manager
int SPI_finish(void)
SPI_finish closes an existing connection to
the SPI manager. You must call this function after completing the
SPI operations needed during your C function's current invocation.
You do not need to worry about making this happen, however, if you
abort the transaction via elog(ERROR). In that
case SPI will clean itself up automatically.
if properly disconnected
if called from an unconnected C function