Function CreateQueue

src/backend/commands/queue.c:704–995

* CREATE RESOURCE QUEUE */

 * CREATE RESOURCE QUEUE
 */
void
CreateQueue(CreateQueueStmt *stmt)
{
	Relation	pg_resqueue_rel;
	TupleDesc	pg_resqueue_dsc;
	ScanKeyData scankey;
	SysScanDesc sscan;
	HeapTuple	tuple;
	Oid			queueid;
	Cost		thresholds[NUM_RES_LIMIT_TYPES];
	Datum		new_record[Natts_pg_resqueue];
	bool		new_record_nulls[Natts_pg_resqueue];
	ListCell    *option;
	ListCell    *pWithList = NULL;

	/* thresholds for active and cost limiters. */
	Cost		activelimit = INVALID_RES_LIMIT_THRESHOLD;	
	Cost		costlimit	= INVALID_RES_LIMIT_THRESHOLD;

	/* overcommit indicator */
	bool		overcommit = false;

	/* cost ignore limit for queries */
	float4		ignorelimit = 0;

	DefElem     *dactivelimit = NULL;
	DefElem     *dcostlimit	  = NULL;
	DefElem     *dovercommit  = NULL;
	DefElem     *dignorelimit = NULL;
	bool		 queueok	  = false;
	bool		 bWith		  = false;

	/* Permission check - only superuser can create queues. */
	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 errmsg("must be superuser to create resource queues")));

	/* Extract options from the statement node tree */
	foreach(option, stmt->options)
	{
		DefElem    *defel = (DefElem *) lfirst(option);

		if (strcmp(defel->defname, "active_statements") == 0)
		{
			if (dactivelimit)
				ereport(ERROR,
						(errcode(ERRCODE_SYNTAX_ERROR),
						 errmsg("conflicting or redundant options")));
			dactivelimit = defel;
		}
		else if (strcmp(defel->defname, "max_cost") == 0)
		{
			if (dcostlimit)
				ereport(ERROR,
						(errcode(ERRCODE_SYNTAX_ERROR),
						 errmsg("conflicting or redundant options")));
			dcostlimit = defel;