I wrote a function in the oracle database that calculates saldo and finds the date of the operation. Here’s how it works:
- He will receive
- Start subtracting the first cell of TURNOVER_DEBIT column from the vSumm and save it.
- Then, from the saved number, subtract the next cell again
- And so on until vSumm becomes less than or equal to 0.
- When vSumm <= 0 it grabes and return OPER_DAY record.
It is taking over 20 minutes. Because the average saldo records for per customer is 70-80 and It is looping for 140 000 clients.
How can I optimize my query? Any help would be much appreciated! Thank you.
create function get_date_overdue (iAccount varchar2, iSaldo number, iDate date := get_operday()) return date is version CONSTANT char(14) := '->>26112020<<-'; vDate date; vSumm number(22) := iSaldo; vSign integer := 0; begin for r in ( select --+ index_desc(s UK_SALDO_ACCOUNT_DAY) * from ibs.Saldo@iabs s where s.ACCOUNT_CODE = iAccount and s.OPER_DAY between date '2015-01-01' and iDate ) loop vSumm := vSumm - r.TURNOVER_DEBIT; if vSign = 0 and vSumm <= 0 then vDate := r.OPER_DAY; vSign := 1; end if; EXIT WHEN vSign = 1; end loop; return vDate; exception when NO_DATA_FOUND then return null; end;
You can use the single query to fetch the
OPER_DAY with the mentioned requirement and then return it from the function as follows:
SELECT OPER_DAY INTO vDate FROM (SELECT SUM(S.TURNOVER_DEBIT) OVER(ORDER BY OPER_DAY DESC NULLS LAST) AS SUM_TURNOVER_DEBIT, OPER_DAY FROM IBS.SALDO@IABS S WHERE S.ACCOUNT_CODE = IACCOUNT AND S.OPER_DAY BETWEEN DATE '2015-01-01' AND IDATE) WHERE SUM_TURNOVER_DEBIT >= ISALDO ORDER BY OPER_DAY DESC FETCH FIRST ROW ONLY;
Here, I have considered that you want to scan from highest
OPER_DAY to lowest
OPER_DAY to sum the
TURNOVER_DEBIT and once the sum of the
TURNOVER_DEBIT becomes equal or more than
ISALDO, the scan should stop and you must return that
A single query can give results way faster than looping through each and every record of the table, do some arithmetic, and take decisions based on that arithmetic.