EXPLAIN SELECT zm.xfdc_index, sum(ald.encash_amt) / 100 - sum( arld.paid_prin_amt + arld.paid_ovd_prin_amt ) / 100 FROM cm_zm_das_info zm, ants_loan_detail ald LEFT JOIN ( SELECT contract_no, business_date, sum(paid_prin_amt) AS paid_prin_amt, sum(paid_ovd_prin_amt) AS paid_ovd_prin_amt FROM ants_repay_loan_detail WHERE business_date <= '2019-02-28' GROUP BY contract_no ) arld ON ald.contract_no = arld.contract_no WHERE ald.business_date <= '2019-02-28' AND zm.ic_number = ald.cert_no GROUP BY zm.xfdc_index order by null ;
zm.xfdc_index,
sum(ald.encash_amt) / 100 - sum(
arld.paid_prin_amt + arld.paid_ovd_prin_amt
) / 100
FROM
cm_zm_das_info zm,
ants_loan_detail ald LEFT JOIN
(
SELECT
contract_no,
business_date,
sum(paid_prin_amt) AS paid_prin_amt,
sum(paid_ovd_prin_amt) AS paid_ovd_prin_amt
FROM
ants_repay_loan_detail
WHERE
business_date <= '2019-02-28'
GROUP BY
contract_no
) arld ON ald.contract_no = arld.contract_no
WHERE
ald.business_date <= '2019-02-28'
AND zm.ic_number = ald.cert_no
GROUP BY
zm.xfdc_index
order by null ;
ants_loan_detail(cert_no,business_date);
ants_repay_loan_detail(business_date,contract_no);
以上语句,on后边的内容,不会走a表的索引。where后的条件,才可以能会走a表的索引。