我该如何建立索引?
表名:Tbl
字段:
F1 CHAR(4)
F2 CHAR(1)
F3 SMALLDATETIME
F4 CHAR(5)
F5 CHAR(5)
F6 CHAR(5)
F7 CHAR(5)
F8 CHAR(6)
其中,F1+F2+F3为唯一主键
查询语句
SELECT * FROM Tbl WHERE F1 = ‘A001’ AND F2 = ‘A’ AND F3 = ‘2001-11023’
SELECT * FROM Tbl WHERE F2 = 'A' AND F3 = '2001-11-23' ORDER BY F1
SELECT COUNT(*) FROM Tbl WHERE F1 = ‘A’ AND F2 = '2001-11-23’ AND F4 = '90027'
SELECT COUNT(*) FROM Tbl WHERE F1 = ‘A’ AND F2 = '2001-11-23' AND F5 = 'FT001'
SELECT COUNT(*) FROM Tbl WHERE F1 = ‘A’ AND F2 = '2001-11-23' AND (F6 = '60001' OR F7 = '60001' OR F8 = '60001')
整个表的记录数一年大概14万条,语句2返回记录数大概100条,语句3、4、5为1条,每条语句均频繁使用