SPI_register_relation - Man Page

int SPI_register_relation(EphemeralNamedRelation enr)

SPI_register_relation makes an ephemeral named relation, with associated information, available to queries planned and executed through the current SPI connection​.

EphemeralNamedRelation enr

If the execution of the command was successful then the following (nonnegative) value will be returned:

SPI_OK_REL_REGISTER

if the relation has been successfully registered by name

On error, one of the following negative values is returned:

SPI_ERROR_ARGUMENT

if enr is NULL or its name field is NULL

SPI_ERROR_UNCONNECTED

if called from an unconnected C function

SPI_ERROR_REL_DUPLICATE

if the name specified in the name field of enr is already registered for this connection