Function CreateExecutorState

src/backend/executor/execUtils.c:123–219

---------------- * CreateExecutorState * * Create and initialize an EState node, which is the root of * working storage for an entire Executor invocation. * * Principally, this creates the per-query memory context that will be * used to hold all working data that lives till the end of the query. * Note that the per-query context will become a child of the caller's * CurrentMemoryContex

 * ----------------
 */
EState *
CreateExecutorState(void)
{
	EState	   *estate;
	MemoryContext qcontext;
	MemoryContext oldcontext;

	/*
	 * Create the per-query context for this Executor run.
	 */
	qcontext = AllocSetContextCreate(CurrentMemoryContext,
									 "ExecutorState",
									 ALLOCSET_DEFAULT_SIZES);
	MemoryContextDeclareAccountingRoot(qcontext);

	/*
	 * Make the EState node within the per-query context.  This way, we don't
	 * need a separate pfree() operation for it at shutdown.
	 */
	oldcontext = MemoryContextSwitchTo(qcontext);

	estate = makeNode(EState);

	/*
	 * Initialize all fields of the Executor State structure
	 */
	estate->es_direction = ForwardScanDirection;
	estate->es_snapshot = InvalidSnapshot;	/* caller must initialize this */
	estate->es_crosscheck_snapshot = InvalidSnapshot;	/* no crosscheck */
	estate->es_range_table = NIL;
	estate->es_range_table_size = 0;
	estate->es_relations = NULL;
	estate->es_rowmarks = NULL;
	estate->es_plannedstmt = NULL;

	estate->es_junkFilter = NULL;

	estate->es_output_cid = (CommandId) 0;

	estate->es_result_relations = NULL;
	estate->es_opened_result_relations = NIL;
	estate->es_tuple_routing_result_relations = NIL;
	estate->es_trig_target_relations = NIL;

	estate->es_param_list_info = NULL;
	estate->es_param_exec_vals = NULL;

	estate->es_queryEnv = NULL;

	estate->es_query_cxt = qcontext;

	estate->es_tupleTable = NIL;

	estate->es_processed = 0;

	estate->es_top_eflags = 0;
	estate->es_instrument = 0;
	estate->es_finished = false;