centos man page for spi_cursor_open

SPI_CURSOR_OPEN(3)					  PostgreSQL 9.2.7 Documentation					SPI_CURSOR_OPEN(3)

NAME
       SPI_cursor_open - set up a cursor using a statement created with SPI_prepare

SYNOPSIS
       Portal SPI_cursor_open(const char * name, SPIPlanPtr plan,
			      Datum * values, const char * nulls,
			      bool read_only)

DESCRIPTION
       SPI_cursor_open sets up a cursor (internally, a portal) that will execute a statement prepared by SPI_prepare. The parameters have the same
       meanings as the corresponding parameters to SPI_execute_plan.

       Using a cursor instead of executing the statement directly has two benefits. First, the result rows can be retrieved a few at a time,
       avoiding memory overrun for queries that return many rows. Second, a portal can outlive the current procedure (it can, in fact, live to the
       end of the current transaction). Returning the portal name to the procedure's caller provides a way of returning a row set as result.

       The passed-in parameter data will be copied into the cursor's portal, so it can be freed while the cursor still exists.

ARGUMENTS
       const char * name
	   name for portal, or NULL to let the system select a name

       SPIPlanPtr plan
	   prepared statement (returned by SPI_prepare)

       Datum * values
	   An array of actual parameter values. Must have same length as the statement's number of arguments.

       const char * nulls
	   An array describing which parameters are null. Must have same length as the statement's number of arguments.  n indicates a null value
	   (entry in values will be ignored); a space indicates a nonnull value (entry in values is valid).

	   If nulls is NULL then SPI_cursor_open assumes that no parameters are null.

       bool read_only
	   true for read-only execution

RETURN VALUE
       Pointer to portal containing the cursor. Note there is no error return convention; any error will be reported via elog.

PostgreSQL 9.2.7						    2014-02-17							SPI_CURSOR_OPEN(3)