Historical version. PostgreSQL 7.3 has reached end of support. See the current manual.
SPI_finish
Description
SPI_finish closes an existing connection to the
SPI manager.
You must call this function after completing the SPI operations needed
during your procedure's current invocation.
You may get the error return SPI_ERROR_UNCONNECTED if SPI_finish is
called without having a current valid connection.
There is no fundamental problem
with this; it means that nothing was done by the SPI manager.
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Read the upstream documentation. For corrections, first check the current manual.