SPI_saveplan
SPI_saveplan — save a prepared statement
Synopsis
SPIPlanPtr SPI_saveplan(SPIPlanPtr plan)
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 C function in the current session. 
Arguments
- SPIPlanPtr- plan
- the prepared statement to be saved 
Return Value
 Pointer to the copied statement; or NULL if unsuccessful. On error, SPI_result is set thus: 
- SPI_ERROR_ARGUMENT
- if - planis- NULLor invalid
- SPI_ERROR_UNCONNECTED
- if called from an unconnected C function 
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.