改進慢查詢。附慢查詢日誌

下面是我的 .NET 應用程序執行時的慢查詢日誌。請讓我知道如何提高查詢的性能：

TCP Port: 3306, Named Pipe: (null)
Time                 Id Command    Argument
# Time: 110805 13:25:39
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 0.015625  Lock_time: 0.000000 Rows_sent: 1  Rows_examined: 1373
use stockist;
SET timestamp=1312530939;
SELECT SUM(GROSSAMOUNT) FROM BILLDETAILS WHERE MONTH(BILLDATE) = 8 AND YEAR(BILLDATE) = 2011;
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 0.000000  Lock_time: 0.000000 Rows_sent: 1  Rows_examined: 1373
SET timestamp=1312530939;
SELECT COUNT(BILLNO) FROM BILLDETAILS WHERE MONTH(BILLDATE) = 8 AND YEAR(BILLDATE) = 2011;
# Time: 110805 13:30:32
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 0.078125  Lock_time: 0.046875 Rows_sent: 1  Rows_examined: 1374
SET timestamp=1312531232;
SELECT A.BILLNO AS BILL_NO, DATE_FORMAT(A.BILLDATE,'%d/%m/%Y') AS BILL_DATE, B.PARTYNAME AS PARTY_NAME, A.NETAMOUNT AS NET_AMOUNT FROM BILLDETAILS A, PARTYMASTER B WHERE A.PARTYID = B.PARTYID AND MONTH(A.BILLDATE) = 8 AND YEAR(A.BILLDATE) = 2011 ORDER BY A.BILLNO, A.BILLDATE;
# Time: 110805 13:30:44
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 0.296875  Lock_time: 0.031250 Rows_sent: 407  Rows_examined: 19552
SET timestamp=1312531244;
select a.itemcode as Item_Code, a.itemname as Item_Name, a.stockinhand as Stock_In_Hand, b.mrp As MRP, round((a.stockinhand * b.mrp),2) As Value, date_format(b.invoicedate,'%d/%m/%Y') As Stock_Date from itemmaster a, stockentry b where a.itemid = b.itemid and invoicedate = (select max(invoicedate) from stockentry where itemid = b.itemid) group by a.itemname order by a.itemname;
# Time: 110805 13:30:55
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 0.000000  Lock_time: 0.000000 Rows_sent: 1  Rows_examined: 1
SET timestamp=1312531255;
SELECT * FROM REMARKSETTINGS;
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 0.000000  Lock_time: 0.000000 Rows_sent: 1  Rows_examined: 1
SET timestamp=1312531255;
SELECT * FROM BILLINGSETTINGS;
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 0.015625  Lock_time: 0.015625 Rows_sent: 1  Rows_examined: 1373
SET timestamp=1312531255;
SELECT MAX(BILLNO) FROM BILLDETAILS WHERE YEAR(BILLDATE) = 2011;
# Time: 110805 13:30:58
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 0.031250  Lock_time: 0.000000 Rows_sent: 184  Rows_examined: 3266
SET timestamp=1312531258;
SELECT B.RECORDID, A.ITEMCODE, A.ITEMNAME, A.STOCKINHAND, B.SALEPRICE FROM ITEMMASTER A, STOCKENTRY B WHERE A.ITEMID = B.ITEMID AND RECORDID = (SELECT MAX(RECORDID) FROM STOCKENTRY WHERE ITEMID = A.ITEMID) AND A.STOCKINHAND > 0 AND B.SALEPRICE > 0 AND B.INVOICEDATE IS NOT NULL ORDER BY A.ITEMNAME, B.INVOICEDATE;
# Time: 110805 13:31:21
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 0.031250  Lock_time: 0.000000 Rows_sent: 184  Rows_examined: 2898
SET timestamp=1312531281;
SELECT B.RECORDID, A.ITEMCODE, A.ITEMNAME, A.STOCKINHAND, B.SALEPRICE FROM ITEMMASTER A, STOCKENTRY B WHERE A.ITEMID = B.ITEMID AND RECORDID = (SELECT MAX(RECORDID) FROM STOCKENTRY WHERE ITEMID = A.ITEMID) AND A.STOCKINHAND > 0 AND B.SALEPRICE > 0 AND B.INVOICEDATE IS NOT NULL AND A.ITEMNAME LIKE '%';
# Time: 110805 13:36:31
# User@Host: root[root] @ localhost [127.0.0.1]
# Query_time: 0.250000  Lock_time: 0.000000 Rows_sent: 407  Rows_examined: 20367
SET timestamp=1312531591;
select c.categoryname, a.itemcode as Item_Code, a.itemname as Item_Name, a.stockinhand as Stock_In_Hand, b.mrp As MRP, round((a.stockinhand * b.mrp),2) As Value, date_format(b.invoicedate,'%d/%m/%Y') As Stock_Date, D.TradeName, D.OwnerAddress, D.OwnerTinNo from itemmaster a, stockentry b, categorymaster c, OwnerDetails D where a.itemid = b.itemid and a.categoryid = c.categoryid and invoicedate = (select max(invoicedate) from stockentry where itemid = b.itemid) group by a.categoryid, a.itemname order by a.itemname;

一個突出的領域是您訪問 BillDetails 表的方式。所有查詢似乎都在 BillDate 上使用 MONTH 和 YEAR 運算符。例如：

SELECT SUM(GROSSAMOUNT) FROM BILLDETAILS WHERE MONTH(BILLDATE) = 8 AND YEAR(BILLDATE) = 2011;

這種方法需要訪問 BillDetails 中的每條記錄。更好的方法是索引 BillDate 並按如下方式查詢：

SELECT SUM(GROSSAMOUNT) FROM BILLDETAILS WHERE BILLDATE BETWEEN '2011-08-01' AND '2011-08-31';

看起來您目前沒有太多數據（1373 行），因此上述差異目前將是最小的，當數量增加時更顯著。

引用自：https://dba.stackexchange.com/questions/4358