请让我知道你寻求什么样的信息来改进这个问题，而不仅仅是否决。

我有一个函数如下所示：

DELIMITER $$
DROP FUNCTION IF EXISTS f_splitadjprice;
CREATE FUNCTION f_splitadjprice (id CHAR(8), startdate DATE)
RETURNS FLOAT 

BEGIN

DECLARE splitfactor FLOAT;
DECLARE splitadjprice FLOAT;

SELECT f_splitfactor(id, startdate) INTO splitfactor;

SELECT (f.p_price FROM fp_v2_fp_basic_prices as f WHERE f.fsym_id = id AND 
f.p_date = startdate) * splitfactor INTO splitadjprice;

RETURN splitadjprice;

END$$
DELIMITER ;

拆分因子的函数为：

DELIMITER $$
DROP FUNCTION IF EXISTS f_splitfactor;
CREATE FUNCTION f_splitfactor (id CHAR(8), startdate DATE)
RETURNS FLOAT

BEGIN

DECLARE splitfactor FLOAT;

SELECT IFNULL(EXP(SUM(LOG(f.p_split_factor))),1) INTO splitfactor
FROM fp_v2_fp_basic_splits AS f
WHERE f.fsym_id = id AND f.p_split_date > startdate AND f.p_split_date < 
NOW();

RETURN splitfactor; 

END$$
DELIMiTER ;

函数fèu splitadjprice运行非常慢。大约14秒。我试着自己运行函数的各个部分。也就是说，函数调用f\u splitfactor并选择（f.p\u price from fp\u v2\u fp\u basic\u prices as f where f.fsym\u id=id and f.p\u date=startdate）。当在函数之外单独运行这两个函数时，它们需要0001秒才能运行。所以整个问题是，只要我想通过嵌套函数进行组合，就需要花费10万倍的时间？