In our application we have a grid where users can page over a large number of records (10-20 million). The grid supports sorting in ascending and descending order in a number of columns (20+). Many of the values are also not unique and so the application also sorts by id as a tie-breaker to make sure that rows always appear on the same page. As an example, should the user want to sort by widget size (starting with the largest), the application generates a query that looks a bit like this:
SELECT TOP 30
* -- (Pretend that there is a list of columns here)
FROM Test
-- WHERE widgetSize > 100
ORDER BY
widgetSize DESC,
id ASC
This query takes ~15s to run (with cached data), the major of the cost appears to be sorting ~1.3m rows by widgetSize. In an attempt to tune this query I discovered that if I add in a WHERE clause restricted to just the largest widgetSizes(commented out in the above query) the query takes just ~800ms (all of the top 50,000 results have a widget size > 100).
Why is the query without the WHERE clause so much slower? I've checked the statistics on the widgetSize column and they show that the top 739 rows have a WidgetSize > 506. As only 30 rows are required can SQL server not use this information to deduce that it only needs to sort rows with a widget size which is large?

I know that I can make this specific query perform quicker by adding in an index on widgetSize and id, however this index is only useful in this specific scenario, and becomes worthless if (for example) the user reverses the sort direction. This table contains many additional columns and each index is large (~200mb) so I can't really afford to add an index for every possible sort order.
Is there some way I can get these queries query to perform without adding an index for every possible sort order? (the user can sort by any one of 20+ columns)
The following script creates the above table and populates it with some representative data. The table is far narrower than the actual table, however still demonstrates the performance that I am seeing. On my PC the query with the where clause takes ~200ms while the query without the where caluse takes ~800ms.
Warning: The resulting database after running this script is ~2Gb in size.
CREATE TABLE Test
(
id INT NOT NULL IDENTITY(1,1) PRIMARY KEY,
widgetSize INT NOT NULL
)
CREATE TABLE #Data
(
widgetSize INT NOT NULL,
recordCount INT NOT NULL
)
INSERT INTO #Data (widgetSize, recordCount)
VALUES
(40826,1),
(30317,1),
(28513,1),
(24255,1),
(20247,1),
(20245,1),
(16445,1),
(15719,1),
(8489,1),
(8486,1),
(4753,1),
(4424,1),
(4409,1),
(3738,1),
(3732,1),
(3725,4),
(3691,1),
(3678,1),
(3655,1),
(3653,3),
(3575,1),
(3572,1),
(3569,1),
(2919,1),
(2903,1),
(2804,1),
(2795,1),
(2765,1),
(2732,1),
(2731,1),
(2677,1),
(2631,1),
(2624,1),
(2548,1),
(2544,1),
(2531,2),
(2516,3),
(2512,1),
(2503,1),
(2502,1),
(2472,1),
(2467,2),
(2460,1),
(2452,1),
(2442,2),
(2439,1),
(2412,1),
(2411,1),
(2405,1),
(2382,1),
(2375,1),
(2348,1),
(2341,1),
(2322,1),
(2321,1),
(2316,1),
(2314,1),
(2291,1),
(2284,1),
(2258,1),
(2251,1),
(2232,1),
(2229,7),
(2222,1),
(2204,1),
(2186,1),
(2173,1),
(2145,2),
(2143,1),
(2113,2),
(2110,1),
(2089,1),
(2082,1),
(2080,1),
(2056,1),
(2054,1),
(2052,1),
(2019,1),
(1991,2),
(1900,1),
(1870,1),
(1869,1),
(1856,1),
(1826,1),
(1802,1),
(1792,1),
(1786,1),
(1784,1),
(1781,1),
(1780,1),
(1771,1),
(1758,1),
(1756,1),
(1749,2),
(1742,1),
(1740,2),
(1729,1),
(1728,1),
(1726,1),
(1718,1),
(1717,1),
(1707,1),
(1701,2),
(1696,1),
(1694,1),
(1688,1),
(1679,1),
(1649,2),
(1632,1),
(1621,1),
(1616,1),
(1588,2),
(1584,1),
(1554,2),
(1539,1),
(1525,1),
(1516,1),
(1515,1),
(1476,1),
(1467,1),
(1463,2),
(1406,1),
(1390,1),
(1370,1),
(1350,1),
(1338,1),
(1335,2),
(1326,1),
(1325,1),
(1316,2),
(1315,1),
(1311,3),
(1308,1),
(1305,1),
(1302,1),
(1299,1),
(1298,1),
(1285,1),
(1283,1),
(1282,1),
(1270,1),
(1261,1),
(1255,1),
(1251,1),
(1250,1),
(1242,1),
(1220,1),
(1219,1),
(1217,1),
(1216,1),
(1193,1),
(1190,1),
(1164,2),
(1147,1),
(1137,3),
(1134,2),
(1133,1),
(1128,2),
(1120,1),
(1113,1),
(1105,1),
(1099,6),
(1098,1),
(1096,2),
(1095,2),
(1092,3),
(1082,1),
(1061,2),
(1050,1),
(1040,1),
(1007,1),
(987,1),
(966,1),
(960,1),
(954,1),
(952,1),
(951,1),
(950,1),
(924,1),
(923,2),
(917,1),
(916,2),
(907,2),
(902,1),
(900,1),
(896,1),
(892,1),
(889,1),
(879,2),
(876,1),
(874,3),
(868,2),
(861,8),
(860,2),
(854,4),
(853,1),
(852,1),
(851,6),
(847,1),
(846,1),
(843,13),
(839,3),
(838,1),
(837,3),
(825,3),
(824,1),
(820,1),
(819,1),
(818,5),
(817,9),
(814,2),
(811,13),
(809,1),
(807,1),
(804,4),
(798,4),
(795,1),
(794,7),
(791,2),
(789,2),
(788,2),
(782,7),
(778,1),
(770,1),
(769,3),
(768,1),
(763,2),
(760,1),
(756,6),
(755,5),
(753,5),
(751,1),
(748,1),
(747,3),
(746,2),
(745,1),
(744,2),
(743,3),
(742,2),
(741,3),
(737,3),
(735,1),
(734,1),
(733,2),
(731,2),
(730,1),
(728,1),
(727,2),
(726,1),
(724,1),
(721,1),
(718,2),
(714,3),
(710,1),
(707,8),
(706,2),
(703,1),
(697,3),
(696,2),
(692,2),
(686,1),
(684,1),
(683,1),
(680,2),
(678,2),
(674,2),
(672,2),
(671,1),
(669,1),
(668,2),
(667,2),
(666,1),
(665,1),
(663,3),
(662,1),
(661,2),
(658,1),
(657,2),
(656,1),
(655,1),
(654,2),
(652,2),
(651,1),
(650,3),
(649,4),
(644,3),
(643,1),
(642,1),
(641,1),
(637,2),
(636,1),
(632,1),
(631,1),
(630,1),
(629,3),
(627,1),
(625,2),
(624,2),
(623,1),
(620,1),
(618,5),
(617,3),
(616,1),
(615,2),
(614,2),
(612,7),
(605,2),
(603,5),
(601,3),
(595,1),
(594,1),
(593,1),
(590,1),
(588,6),
(587,3),
(586,3),
(583,1),
(582,1),
(580,3),
(578,1),
(577,2),
(576,1),
(575,2),
(574,2),
(573,1),
(572,2),
(571,3),
(570,1),
(569,1),
(568,2),
(567,4),
(566,4),
(565,2),
(564,2),
(563,2),
(562,1),
(560,1),
(559,2),
(558,1),
(557,3),
(556,3),
(555,2),
(554,3),
(553,1),
(552,4),
(551,4),
(550,1),
(549,3),
(548,2),
(547,2),
(546,8),
(544,1),
(543,3),
(542,8),
(541,1),
(538,8),
(536,1),
(534,1),
(533,2),
(532,1),
(531,1),
(530,1),
(529,11),
(528,1),
(527,3),
(526,1),
(525,2),
(524,5),
(523,3),
(522,1),
(521,2),
(520,5),
(518,12),
(517,5),
(515,5),
(514,3),
(513,1),
(511,16),
(510,6),
(509,1),
(508,2),
(507,1),
(506,41),
(505,2),
(504,7),
(503,7),
(502,3),
(501,3),
(500,8),
(499,1),
(498,4),
(497,6),
(496,10),
(495,8),
(494,4),
(493,5),
(492,3),
(491,3),
(490,6),
(489,6),
(488,2),
(487,3),
(486,4),
(485,6),
(484,2),
(483,5),
(482,12),
(481,3),
(480,9),
(479,10),
(478,6),
(477,5),
(476,19),
(475,5),
(474,4),
(473,3),
(472,3),
(471,8),
(470,5),
(469,11),
(468,2),
(467,1),
(466,5),
(465,9),
(464,13),
(463,10),
(462,5),
(461,12),
(460,1),
(459,5),
(458,3),
(457,1),
(456,13),
(455,3),
(454,11),
(453,5),
(452,6),
(451,20),
(450,51),
(449,12),
(448,8),
(447,6),
(446,6),
(445,6),
(444,16),
(443,80),
(442,5),
(441,10),
(440,5),
(439,12),
(438,14),
(437,58),
(436,2),
(435,13),
(434,7),
(433,5),
(432,16),
(431,7),
(430,30),
(429,21),
(428,6),
(427,18),
(426,2),
(425,7),
(424,21),
(423,11),
(422,4),
(421,8),
(420,8),
(419,7),
(418,15),
(417,9),
(416,22),
(415,6),
(414,22),
(413,10),
(412,15),
(411,9),
(410,68),
(409,62),
(408,5),
(407,7),
(406,12),
(405,12),
(404,8),
(403,8),
(402,31),
(401,24),
(400,11),
(399,3),
(398,16),
(397,19),
(396,6),
(395,18),
(394,3),
(393,2),
(392,18),
(391,20),
(390,14),
(389,12),
(388,26),
(387,14),
(386,27),
(385,23),
(384,25),
(383,25),
(382,21),
(381,69),
(380,14),
(379,34),
(378,41),
(377,24),
(376,27),
(375,13),
(374,35),
(373,32),
(372,43),
(371,28),
(370,30),
(369,27),
(368,21),
(367,23),
(366,36),
(365,45),
(364,42),
(363,82),
(362,16),
(361,33),
(360,29),
(359,15),
(358,19),
(357,17),
(356,29),
(355,11),
(354,18),
(353,29),
(352,5),
(351,6),
(350,9),
(349,17),
(348,11),
(347,17),
(346,16),
(345,20),
(344,15),
(343,14),
(342,19),
(341,7),
(340,13),
(339,13),
(338,23),
(337,13),
(336,15),
(335,9),
(334,6),
(333,10),
(332,30),
(331,22),
(330,21),
(329,13),
(328,8),
(327,10),
(326,50),
(325,16),
(324,18),
(323,17),
(322,26),
(321,18),
(320,24),
(319,18),
(318,20),
(317,6),
(316,19),
(315,17),
(314,14),
(313,39),
(312,29),
(311,23),
(310,21),
(309,27),
(308,27),
(307,14),
(306,19),
(305,27),
(304,42),
(303,29),
(302,38),
(301,47),
(300,19),
(299,9),
(298,14),
(297,46),
(296,11),
(295,20),
(294,20),
(293,16),
(292,23),
(291,27),
(290,35),
(289,20),
(288,15),
(287,21),
(286,22),
(285,33),
(284,24),
(283,11),
(282,25),
(281,17),
(280,47),
(279,22),
(278,15),
(277,26),
(276,18),
(275,20),
(274,29),
(273,53),
(272,28),
(271,17),
(270,20),
(269,30),
(268,15),
(267,40),
(266,143),
(265,35),
(264,11),
(263,30),
(262,32),
(261,39),
(260,52),
(259,96),
(258,31),
(257,18),
(256,35),
(255,52),
(254,24),
(253,35),
(252,64),
(251,34),
(250,21),
(249,45),
(248,52),
(247,64),
(246,131),
(245,108),
(244,36),
(243,34),
(242,45),
(241,50),
(240,38),
(239,57),
(238,55),
(237,62),
(236,31),
(235,82),
(234,43),
(233,40),
(232,43),
(231,58),
(230,38),
(229,38),
(228,38),
(227,69),
(226,23),
(225,54),
(224,90),
(223,91),
(222,60),
(221,277),
(220,70),
(219,33),
(218,42),
(217,100),
(216,185),
(215,98),
(214,108),
(213,57),
(212,54),
(211,77),
(210,150),
(209,175),
(208,46),
(207,199),
(206,158),
(205,68),
(204,85),
(203,129),
(202,75),
(201,59),
(200,73),
(199,123),
(198,72),
(197,155),
(196,193),
(195,66),
(194,119),
(193,119),
(192,80),
(191,80),
(190,96),
(189,284),
(188,108),
(187,79),
(186,118),
(185,93),
(184,92),
(183,194),
(182,152),
(181,96),
(180,134),
(179,108),
(178,121),
(177,91),
(176,140),
(175,262),
(174,159),
(173,121),
(172,134),
(171,118),
(170,116),
(169,168),
(168,297),
(167,171),
(166,214),
(165,474),
(164,176),
(163,131),
(162,215),
(161,310),
(160,175),
(159,183),
(158,208),
(157,377),
(156,248),
(155,804),
(154,452),
(153,133),
(152,224),
(151,826),
(150,299),
(149,367),
(148,427),
(147,413),
(146,1190),
(145,796),
(144,450),
(143,334),
(142,308),
(141,707),
(140,580),
(139,601),
(138,403),
(137,351),
(136,411),
(135,547),
(134,528),
(133,506),
(132,306),
(131,485),
(130,419),
(129,832),
(128,1034),
(127,894),
(126,1168),
(125,313),
(124,787),
(123,1079),
(122,984),
(121,1086),
(120,1525),
(119,1007),
(118,539),
(117,1596),
(116,1307),
(115,2081),
(114,1256),
(113,2200),
(112,1184),
(111,535),
(110,1404),
(109,1219),
(108,1675),
(107,1765),
(106,1784),
(105,890),
(104,931),
(103,1769),
(102,1720),
(101,1528),
(100,1639),
(99,1955),
(98,1434),
(97,979),
(96,2295),
(95,2516),
(94,3043),
(93,2972),
(92,3493),
(91,1873),
(90,1047),
(89,2228),
(88,2328),
(87,1804),
(86,5243),
(85,2256),
(84,1602),
(83,898),
(82,2025),
(81,2207),
(80,2559),
(79,2720),
(78,3302),
(77,5410),
(76,994),
(75,2767),
(74,3343),
(73,3951),
(72,4116),
(71,6164),
(70,2992),
(69,2066),
(68,18269),
(67,13159),
(66,13142),
(65,7387),
(64,8759),
(63,4887),
(62,1847),
(61,10239),
(60,6990),
(59,8785),
(58,8161),
(57,10081),
(56,4899),
(55,1744),
(54,9916),
(53,8713),
(52,9529),
(51,8827),
(50,10255),
(49,6392),
(48,2253),
(47,9939),
(46,12083),
(45,12103),
(44,12667),
(43,19758),
(42,9699),
(41,5450),
(40,26566),
(39,41836),
(38,48441),
(37,49562),
(36,71987),
(35,32390),
(34,7159),
(33,179598),
(32,158675),
(31,132676),
(30,151839),
(29,139014),
(28,632065),
(27,7800),
(26,259440),
(25,215240),
(24,170986),
(23,157141),
(22,167304),
(21,20408),
(20,11949),
(19,267541),
(18,208096),
(17,174708),
(16,156445),
(15,153569),
(14,73937),
(13,73821),
(12,310246),
(11,231829),
(10,179047),
(9,145506),
(8,133433),
(7,108736),
(6,73381),
(5,84825),
(4,86641),
(3,86172),
(2,87690),
(1,148110),
(0,7960761),
(-1,861),
(-2,365),
(-3,356),
(-4,578),
(-5,293),
(-6,310),
(-7,414),
(-8,748),
(-9,113),
(-10,782),
(-11,705),
(-12,711),
(-13,915),
(-14,539),
(-15,70),
(-16,21),
(-17,40),
(-18,56),
(-19,52),
(-20,34),
(-21,46),
(-22,20),
(-23,10),
(-24,24),
(-25,44),
(-26,18),
(-27,13),
(-28,4),
(-29,3),
(-30,6),
(-31,2),
(-58,1),
(-59,13),
(-60,2),
(-61,2),
(-64,1),
(-70,1),
(-97,1),
(-145,1),
(-234,1),
(-239,2),
(-240,2),
(-272,2),
(-273,1),
(-274,1),
(-276,4),
(-1094,1),
(-1096,1),
(-1337,1),
(-1341,1),
(-3545,1),
(-3547,1),
(-10962,1),
(-10964,1),
(-255449,1),
(-255470,1),
(-365104,1),
(-365105,1)
DECLARE c CURSOR FOR
SELECT widgetSize, recordCount FROM #Data
OPEN c
DECLARE @widgetSize INT
DECLARE @rowCount INT
FETCH NEXT FROM c INTO @widgetSize, @rowCount
WHILE @@FETCH_STATUS = 0
BEGIN
;WITH cte AS
(
SELECT rowNumber = 1
UNION ALL
SELECT rowNumber + 1
FROM cte
WHERE rowNumber < @rowCount
)
INSERT INTO Test
(
widgetSize
)
SELECT
@widgetSize
FROM cte
OPTION (MAXRECURSION 0)
FETCH NEXT FROM c INTO @widgetSize, @rowCount
END
CLOSE c
DEALLOCATE c
DROP TABLE #Data
CREATE STATISTICS WidgetSize
ON Test (WidgetSize) WITH FULLSCAN



