SPI_saveplan
Description
  
   SPI_saveplan
  
  copies a passed statement (prepared by
  
   SPI_prepare
  
  ) into memory that will not be freed
   by
  
   SPI_finish
  
  nor by the transaction manager,
   and returns a pointer to the copied statement.  This gives you the
   ability to reuse prepared statements in the subsequent invocations of
   your procedure in the current session.
 
Return Value
Pointer to the copied statement; or NULL if unsuccessful. On error, SPI_result is set thus:
- SPI_ERROR_ARGUMENT
 - 
    
if plan is NULL or invalid
 - SPI_ERROR_UNCONNECTED
 - 
    
if called from an unconnected procedure
 
Notes
  The originally passed-in statement is not freed, so you might wish to do
  
   SPI_freeplan
  
  on it to avoid leaking memory
   until
  
   SPI_finish
  
  .
 
  In most cases,
  
   SPI_keepplan
  
  is preferred to this
   function, since it accomplishes largely the same result without needing
   to physically copy the prepared statement's data structures.