Pfthb

I have two functions. The second function uses the output from the first function.

One is:

DELIMITER $$
DROP FUNCTION IF EXISTS fp_splitfactor;
CREATE FUNCTION fp_splitfactor_price (id CHAR(8), startdate DATE)
RETURNS FLOAT
BEGIN
DECLARE splitfactor FLOAT;
SELECT IFNULL(EXP(SUM(LOG(f.p_split_factor))),1) INTO splitfactor
FROM fp_v2_fp_basic_splits AS f
WHERE f.fsym_id = id AND f.p_split_date > startdate AND f.p_split_date < NOW();
RETURN splitfactor; 
END$$
DELIMiTER ;

Second one is:

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

BEGIN
DECLARE splitfactor FLOAT;
DECLARE splitadjprice FLOAT;
DECLARE spinofffactor FLOAT;

SET splitfactor = 1.0;

SELECT fp_splitfactor(id, startdate) INTO splitfactor;

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

RETURN splitadjprice;
END$$
DELIMITER ;

I then try to exectute a query as the following:

SELECT 
p.fsym_id, 
b.p_co_sec_name_desc AS Company_Name,
b.region AS Region,
p.p_date,
p.p_price AS Unadjusted_Price,
fp_splitadjprice(p.fsym_id,p_date) AS Adjusted_Price
FROM
fp_v2_fp_basic_prices p
LEFT JOIN (
 SELECT r2.region, b2.p_co_sec_name_desc, b2.fsym_id
 FROM fp_v2_fp_sec_coverage b2
 LEFT JOIN sym_v1_sym_region r2 ON b2.fsym_id = r2.fsym_id
 WHERE r2.region = "EUR") b
 ON b.fsym_id =p.fsym_id

So basically my query calls the second function, which then calls the first function in order to return a value to the query. The execution is extremely slow though, but I do not understand why that is the case?

I found out that the slow execution was entire due to MySQL workbench not handling large datasets well. Once I migrated everything to BigQuery on Google Cloud everything worked perfectly.

STAY AWAY FROM CALLING FUNCTIONS ON LARGE DATASETS IN MySQL Workbench!