如何提高查询效率？

我新建了一个表，字段是所属单位
里面存储的数据是：
1001,1003,1179,1010,1012,6231,1014,1019,1016,1018,1020,1027,6232,1030,2368,6403,1033,1048,6404,2268,1011,2270,5502,6233,6949,6947,1032,6155,1029,7045,7044,7054,7058,7057,7056,7059,1035,1024,1034,1038,1046,6059,6485,6508,6509,6941,6965,7016,7137,7134,7135,7136,1050,1051,1052,1054,6596,1055,1056,1057,1058,1060,1061,1062,1063,1065,1068,5850,1069,5950,1070,5839,6948,1073,1074,1075,1076,1079,1080,7169,1081,1084,1085,1086,1088,1094,6066,1097,1098,6507,2272,5493,5884,5886,5974,6043,1093,7043,7042,7041,7040,7039,7038,1100,1101,6862,1105,1106,1107,6524,1109,1111,1112,6486,7095,1113,6685,1114,1117,1120,1121,2282,5482,5484,6954,5828,6529,5814,1025,6575,1028,1047,1042,3829,3831,1077,1083,1089,1090,1082,2376,4722,5486,5499,5500,5501,5816,6146,6156,7052,7051,7050,7049,7048,6154,6279,6280,7033,6281,7037,7036,7034,7032查询的时候使用 SELEC * FROM Table WHERE Company IN(...)领导说这样的查询效率很低，说改成2维表  怎么弄好一些？希望各位大侠提供思路