mysql 쿼리가 최적화되지 않았습니다.

Question

이 쿼리를 최적화하려고했지만 특정 비즈니스 요구 사항으로 인해 쿼리를 수행 할 수 없습니다.

테이블 :

• b2 : 약 2mil 기록, 저장 비즈니스 기록
• business_reviews : 작은 테이블, 기업을위한 저장 리뷰 (각 비즈 여러 리뷰를 가질 수 있습니다)
• business_feature_item : 작은 테이블, 저장 비즈니스를위한 기능 (각 비즈는 여러 기능을 가질 수 있습니다.)

결과에 대한 특정 비즈니스 요구 사항은 다음과 같습니다.

• 쇼 비즈니스 기록
• 는 기능도
• b2.starbiz 정렬 및 (MATCH 반대에 의해 생성 된) 점수

을 검색 할 수뿐만 아니라 비즈니스

쇼 관련 리뷰

현재 쿼리가 임시 테이블, 유니온 모두 및 정렬을 사용하므로 결과가 클 경우 잘 작동하지 않습니다. 더 효율적으로 작동하도록이 쿼리를 다시 작성하는 방법이 있습니까?

SELECT temp.* FROM 

(SELECT DISTINCT b.business_id, b.description AS `extra`, '1' AS `type`, 0 as score 

FROM b2 as b 

LEFT JOIN business_feature_item AS i ON b.business_id = i.business_id 

WHERE ((b.cat_id = '93' OR b.cat_id2 = '93' OR b.cat_id3 = '93')) 

AND b.city_id = '152262' 

AND `approved`=1 

UNION ALL SELECT b.business_id, review_desc AS `extra`, '2' AS `type`, ((MATCH   `review_desc` AGAINST ('"restaurants"' IN BOOLEAN MODE) * 4) + (MATCH `review_desc` AGAINST ('restaurants' IN BOOLEAN MODE))) AS score 

FROM b2 AS b, business_reviews AS r 

WHERE b.business_id =r.business_id 

AND b.city_id = '152262' 

AND (MATCH `review_desc` AGAINST ('"restaurants"' IN BOOLEAN MODE) 

OR MATCH `review_desc` AGAINST ('restaurants' IN BOOLEAN MODE))) 

AS temp 

GROUP BY temp.business_id 

ORDER BY starbiz DESC, score DESC 

Answer 1

MySQL이 어떤 인덱스를 사용하지하게, 대신 풀 테이블 스캔을 할 것 OR 절을 사용.

대신 OR의의 UNION ALL의를 사용하는 쿼리를 다시 작성하십시오 :

SELECT temp.* FROM 
(
    SELECT DISTINCT 
     b.business_id, 
     b.description AS `extra`, 
     '1' AS `type`, 
     0 as score 
    FROM 
     b2 as b 
    LEFT JOIN 
     business_feature_item AS i ON b.business_id = i.business_id 
    WHERE 
     b.cat_id = '93' 
     AND b.city_id = '152262' 
     AND `approved`=1 
UNION ALL 
    SELECT DISTINCT 
     b.business_id, 
     b.description AS `extra`, 
     '1' AS `type`, 
     0 as score 
    FROM 
     b2 as b 
    LEFT JOIN 
     business_feature_item AS i ON b.business_id = i.business_id 
    WHERE 
     b.cat_id2 = '93' 
     AND b.city_id = '152262' 
     AND `approved`=1 
UNION ALL 
    SELECT DISTINCT 
     b.business_id, 
     b.description AS `extra`, 
     '1' AS `type`, 
     0 as score 
    FROM 
     b2 as b 
    LEFT JOIN 
     business_feature_item AS i ON b.business_id = i.business_id 
    WHERE 
     b.cat_id3 = '93' 
     AND b.city_id = '152262' 
     AND `approved`=1 
UNION ALL 
    SELECT 
     b.business_id, 
     review_desc AS `extra`, 
     '2' AS `type`, 
     MATCH `review_desc` AGAINST ('"restaurants"' IN BOOLEAN MODE) * 4 AS score 
    FROM 
     b2 AS b, 
     business_reviews AS r 
    WHERE 
     b.business_id =r.business_id 
     AND b.city_id = '152262' 
     AND MATCH `review_desc` AGAINST ('"restaurants"' IN BOOLEAN MODE) 
UNION ALL 
    SELECT 
     b.business_id, 
     review_desc AS `extra`, 
     '2' AS `type`, 
     MATCH `review_desc` AGAINST ('restaurants' IN BOOLEAN MODE) AS score 
    FROM 
     b2 AS b, 
     business_reviews AS r 
    WHERE 
     b.business_id =r.business_id 
     AND b.city_id = '152262' 
     AND MATCH `review_desc` AGAINST ('restaurants' IN BOOLEAN MODE) 
) 
AS temp 
GROUP BY temp.business_id 
ORDER BY starbiz DESC, score DESC