centos man page for spi_push

SPI_PUSH(3)						  PostgreSQL 9.2.7 Documentation					       SPI_PUSH(3)

NAME
       SPI_push - push SPI stack to allow recursive SPI usage

SYNOPSIS
       void SPI_push(void)

DESCRIPTION
       SPI_push should be called before executing another procedure that might itself wish to use SPI. After SPI_push, SPI is no longer in a
       "connected" state, and SPI function calls will be rejected unless a fresh SPI_connect is done. This ensures a clean separation between your
       procedure's SPI state and that of another procedure you call. After the other procedure returns, call SPI_pop to restore access to your own
       SPI state.

       Note that SPI_execute and related functions automatically do the equivalent of SPI_push before passing control back to the SQL execution
       engine, so it is not necessary for you to worry about this when using those functions. Only when you are directly calling arbitrary code
       that might contain SPI_connect calls do you need to issue SPI_push and SPI_pop.

PostgreSQL 9.2.7						    2014-02-17							       SPI_PUSH(3)