매우 느린 쿼리

Question

나는 완전히 mysql에 익숙하며 아래의 mysql 쿼리를 실행하려고 시도했지만 엄청나게 천천히 달리고있는 것으로 보인다. 표는 약 100MB이고 약 2 백만 행이 들어 있습니다.

Create TEMPORARY table temp_table as 
(
SELECT 
    pcur.RECORD_ID, 
    pcur.Price, 
    (pcur.Price - plast.Price) as 'Price_Difference', 
     CASE 
     when plast.Price between 0 and 0.25 then ((pcur.Price - plast.Price)/0.001) 
     when plast.Price between 0.2501 and 0.5 then ((pcur.Price - plast.Price)/0.005) 
     when plast.Price between 0.5001 and 10 then ((pcur.Price - plast.Price)/0.01) 
     when plast.Price between 10.0001 and 20 then ((pcur.Price - plast.Price)/0.02) 
     when plast.Price between 20.0001 and 100 then ((pcur.Price - plast.Price)/0.05) 
     when plast.Price between 100.0001 and 200 then ((pcur.Price - plast.Price)/0.1) 
     when plast.Price between 200.0001 and 500 then ((pcur.Price - plast.Price)/0.2) 
     when plast.Price between 500.0001 and 1000 then ((pcur.Price - plast.Price)/0.5) 
     when plast.Price between 1000.0001 and 2000 then ((pcur.Price - plast.Price)/1) 
     when plast.Price between 2000.0001 and 5000 then ((pcur.Price - plast.Price)/2) 
     when plast.Price between 5000.0001 and 9995 then ((pcur.Price - plast.Price)/5) 
    END AS Price_Diff_Ticks 
FROM 
    /* First aliased table is the current record */ 
    00005 pcur 
    /* Second aliased table is the previous one, whose id is one behind */ 
    LEFT JOIN 00005 plast ON (pcur.Record_ID = plast.Record_ID + 1) 

) 
; 

테이블의 인덱스 보고서.

"Table" "Non_unique" "Key_name" "Seq_in_index" "Column_name" "Collation" "Cardinality" "Sub_part" "Packed" "Null" "Index_type" "Comment" "Index_comment" 
============================================================================================ 
"00005" "0" "PRIMARY" "1" "RECORD_ID" "A" "2275579" "" "" "" "BTREE" "" "" 

무엇이 잘못 되었나요? 또는 내가 느리게 만들 수 없었던 것은 무엇입니까?

Answer 1

내가 상상할 수있는 한 가지는 필드 중 하나에 산술 연산이 있기 때문에 MySQL이 인덱스를 사용하지 않거나 비효율적으로 사용한다는 것입니다. 그것은 추측입니다.

변수를 사용하여 쿼리를 작성할 수 있습니다. 내가 선호하는 접근 방식은 아니지만이 경우 작동 할 수 있습니다.

Create TEMPORARY table temp_table as 
SELECT pcur.RECORD_ID, pcur.Price, (pcur.Price - @prevPrice) as 'Price_Difference', 
     CASE 
     when @prevPrice between 0 and 0.25 then ((pcur.Price - @prevPrice)/0.001) 
     when @prevPrice between 0.2501 and 0.5 then ((pcur.Price - @prevPrice)/0.005) 
     when @prevPrice between 0.5001 and 10 then ((pcur.Price - @prevPrice)/0.01) 
     when @prevPrice between 10.0001 and 20 then ((pcur.Price - @prevPrice)/0.02) 
     when @prevPrice between 20.0001 and 100 then ((pcur.Price - @prevPrice)/0.05) 
     when @prevPrice between 100.0001 and 200 then ((pcur.Price - @prevPrice)/0.1) 
     when @prevPrice between 200.0001 and 500 then ((pcur.Price - @prevPrice)/0.2) 
     when @prevPrice between 500.0001 and 1000 then ((pcur.Price - @prevPrice)/0.5) 
     when @prevPrice between 1000.0001 and 2000 then ((pcur.Price - @prevPrice)/1) 
     when @prevPrice between 2000.0001 and 5000 then ((pcur.Price - @prevPrice)/2) 
     when @prevPrice between 5000.0001 and 9995 then ((pcur.Price - @prevPrice)/5) 
    END AS Price_Diff_Ticks, 
    @prevPrice = pcur.Price 
FROM /* First aliased table is the current record */ 
    00005 pcur cross join 
    (select @prevprice := NULL) const 
order by Record_Id;