This e-mail is for the sole use of the intended recipient and contains information that may be privileged and/or confidential. If you are not an intended recipient, please notify the sender by return e-mail and delete this e-mail and any attachments. Certain required legal entity disclosures can be accessed on our website: https://www.thomsonreuters.com/en/resources/disclosures.htmlFollow Postgres expert,
We have a flavor of this type of query with long in-list/bind variables (see below). We notice that some of the bind variables come in as 0 which causes the optimizer to choose to full scan two of the following 3 tables. One thought to fix a full table scan is to chop off the not-needed bind variables (proven to work after some tests). But my other worry is will cause parsing issues because the app will be executing > 100k/sec with this type of query.
I am an Oracle DBA, and this change for sure will generate a different query id. Which in turn generates tons of extra parsing to the DB because all soft and hard parsing occurs at the DB level. But my understanding for Postgres is parsing occurs at the client jdbc level. Am I understanding this correctly?
In summary/my concern:
1) Where does query parsing occur?
2) Will this cause extra parsing to the posgress DB? Any pg system table to measure parsing?
SELECT abc, efg from DOCLOC a, COLLECTION b WHERE a.colum1 IN ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $30, $31, $32, $33, $34, $35, $36, $37, $38, $39, $40, $41, $42, $43, $44, $45, $46, $47, $48, $49, $50, $51, $52, $53, $54, $55, $56, $57, $58, $59, $60, $61, $62, $63, $64, $65, $66, $67, $68, $69, $70, $71, $72, $73, $74, $75, $76, $77, $78, $79, $80, $81, $82, $83, $84, $85, $86, $87, $88, $89, $90, $91, $92, $93, $94, $95, $96, $97, $98, $99, $100, $101, $102, $103, $104, $105, $106, $107, $108, $109, $110, $111, $112, $113, $114, $115, $116, $117, $118, $119, $120, $121, $122, $123, $124, $125, $126, $127, $128, $129, $130, $131, $132, $133, $134, $135, $136, $137, $138, $139, $140, $141, $142, $143, $144, $145, $146, $147, $148, $149, $150, $151, $152, $153, $154, $155, $156, $157, $158, $159, $160, $161, $162, $163, $164, $165, $166, $167, $168, $169, $170, $171, $172, $173, $174, $175, $176, $177, $178, $179, $180, $181, $182, $183, $184, $185, $186, $187, $188, $189, $190, $191, $192, $193, $194, $195, $196, $197, $198, $199, $200, $201, $202, $203, $204, $205, $206, $207, $208, $209, $210, $211, $212, $213, $214, $215, $216, $217, $218, $219, $220, $221, $222, $223, $224, $225, $226, $227, $228, $229, $230, $231, $232, $233, $234, $235, $236, $237, $238, $239, $240, $241, $242, $243, $244, $245, $246, $247, $248, $249, $250, $251, $252, $253, $254, $255, $256, $257, $258, $259, $260, $261, $262, $263, $264, $265, $266, $267, $268, $269, $270, $271, $272, $273, $274, $275, $276, $277, $278, $279, $280, $281, $282, $283, $284, $285, $286, $287, $288, $289, $290, $291, $292, $293, $294, $295, $296, $297, $298, $299, $300, $301, $302, $303, $304, $305, $306, $307, $308, $309, $310, $311, $312, $313, $314, $315, $316, $317, $318, $319, $320, $321, $322, $323, $324, $325, $326, $327, $328, $329, $330, $331, $332, $333, $334, $335, $336, $337, $338, $339, $340, $341, $342, $343, $344, $345, $346, $347, $348, $349, $350, $351, $352, $353, $354, $355, $356, $357, $358, $359, $360, $361, $362, $363, $364, $365, $366, $367, $368, $369, $370, $371, $372, $373, $374, $375, $376, $377, $378, $379, $380, $381, $382, $383, $384, $385, $386, $387, $388, $389, $390, $391, $392, $393, $394, $395, $396, $397, $398, $399, $400, $401, $402, $403, $404, $405, $406, $407, $408, $409, $410, $411, $412, $413, $414, $415, $416, $417, $418, $419, $420, $421, $422, $423, $424, $425, $426, $427, $428, $429, $430, $431, $432, $433, $434, $435, $436, $437, $438, $439, $440, $441, $442, $443, $444, $445, $446, $447, $448, $449, $450, $451, $452, $453, $454, $455, $456, $457, $458, $459, $460, $461, $462, $463, $464, $465, $466, $467, $468, $469, $470, $471, $472, $473, $474, $475, $476, $477, $478, $479, $480, $481, $482, $483, $484, $485, $486, $487, $488, $489, $490, $491, $492, $493, $494, $495, $496, $497, $498, $499, $500, $501, $502, $503, $504, $505, $506, $507, $508, $509, $510, $511, $512, $513, $514, $515, $516, $517, $518, $519, $520, $521, $522, $523, $524, $525, $526, $527, $528, $529, $530, $531, $532, $533, $534, $535, $536, $537, $538, $539, $540, $541, $542, $543, $544, $545, $546, $547, $548, $549, $550, $551, $552, $553, $554, $555, $556, $557, $558, $559, $560, $561, $562, $563, $564, $565, $566, $567, $568, $569, $570, $571, $572, $573, $574, $575, $576, $577, $578, $579, $580, $581, $582, $583, $584, $585, $586, $587, $588, $589, $590, $591, $592, $593, $594, $595, $596, $597, $598, $599, $600, $601, $602, $603, $604, $605, $606, $607, $608, $609, $610, $611, $612, $613, $614, $615, $616, $617, $618, $619, $620, $621, $622, $623, $624, $625, $626, $627, $628, $629, $630, $631, $632, $633, $634, $635, $636, $637, $638, $639, $640, $641, $642, $643, $644, $645, $646, $647, $648, $649, $650, $651, $652, $653, $654, $655, $656, $657, $658, $659, $660, $661, $662, $663, $664, $665, $666, $667, $668, $669, $670, $671, $672, $673, $674, $675, $676, $677, $678, $679, $680, $681, $682, $683, $684, $685, $686, $687, $688, $689, $690, $691, $692, $693, $694, $695, $696, $697, $698, $699, $700, $701, $702, $703, $704, $705, $706, $707, $708, $709, $710, $711, $712, $713, $714, $715, $716, $717, $718, $719, $720, $721, $722, $723, $724, $725, $726, $727, $728, $729, $730, $731, $732, $733, $734, $735, $736, $737, $738, $739, $740, $741, $742, $743, $744, $745, $746, $747, $748, $749, $750, $751, $752, $753, $754, $755, $756, $757, $758, $759, $760, $761, $762, $763, $764, $765, $766, $767, $768, $769, $770, $771, $772, $773, $774, $775, $776, $777, $778, $779, $780, $781, $782, $783, $784, $785, $786, $787, $788, $789, $790, $791, $792, $793, $794, $795, $796, $797, $798, $799, $800, $801, $802, $803, $804, $805, $806, $807, $808, $809, $810, $811, $812, $813, $814, $815, $816, $817, $818, $819, $820, $821, $822, $823, $824, $825, $826, $827, $828, $829, $830, $831, $832, $833, $834, $835, $836, $837, $838, $839, $840, $841, $842, $843, $844, $845, $846, $847, $848, $849, $850, $851, $852, $853, $854, $855, $856, $857, $858, $859, $860, $861, $862, $863, $864, $865, $866, $867, $868, $869, $870, $871, $872, $873, $874, $875, $876, $877, $878, $879, $880, $881, $882, $883, $884, $885, $886, $887, $888, $889, $890, $891, $892, $893, $894, $895, $896, $897, $898, $899, $900, $901, $902, $903, $904, $905, $906, $907, $908, $909, $910, $911, $912, $913, $914, $915, $916, $917, $918, $919, $920, $921, $922, $923, $924, $925, $926, $927, $928, $929, $930, $931, $932, $933, $934, $935, $936, $937, $938, $939, $940, $941, $942, $943, $944, $945, $946, $947, $948, $949, $950, $951, $952, $953, $954, $955, $956, $957, $958, $959, $960, $961, $962, $963, $964, $965, $966, $967, $968, $969, $970, $971, $972, $973, $974, $975, $976, $977, $978, $979, $980, $981, $982, $983, $984, $985, $986, $987, $988, $989, $990, $991, $992, $993, $994, $995, $996, $997, $998, $999, $1000) AND a.COLLECTION_NAME=b.DOCLOC.COLLECTION_NAME AND a.DOCLOC.STAGE_ID=(SELECT MAX (STAGE_ID)
FROM COLLECTION_PIT
WHERE COLLECTION_PIT.COLLECTION_NAME=a.COLLECTION_NAME
AND COLLECTION_PIT.PIT_ID<=$1001 AND COLLECTION_PIT.STAGE_CODE=$1002)
I would usually try to avoid such long IN causes. Why not try this ...... Create a temp table of 1 column. Bulk insert all your IDs into that table. Then change your query to join to the temp table? This also has the advantage of working for 1000s of values.
On Fri, 13 Sept 2024, 16:35 Wong, Kam Fook (TR Technology), <kamfook.wong@xxxxxxxxxxxxxxxxxx> wrote:
