Description:
Two semantically equivalent queries produce very different execution plans and runtimes.
The mutated query only adds a redundant OR FALSE predicate to the top-level WHERE clause:
WHERE P
=>
WHERE P OR FALSE
Since P OR FALSE is equivalent to P, both queries should have the same result and ideally the same optimized plan.
However, MySQL optimizes the mutated query to:
-> Zero rows (Impossible WHERE)
while the original query still uses a complex execution plan with joins, materialization, temporary tables, and duplicate removal.
Both queries return 0 rows, but the original query is much slower.
Original
average_ms: 15.399
median_ms: 16.002
plan: complex plan with joins/materialization/temporary table
rows: 0
Mutated
average_ms: 1.602
median_ms: 1.689
plan: Zero rows (Impossible WHERE)
rows: 0
This is not the same as Bug #120900.
Bug #120900 reports that adding redundant OR FALSE makes the query slower.
This case is the opposite: adding redundant OR FALSE makes the query much faster because it enables Impossible WHERE detection.
The root issue appears to be a missed optimization in the original query.
How to repeat:
-- Compressed reproducer preserving the original query shape.
-- MySQL 9.5.0: adding redundant OR FALSE changes the plan to Impossible WHERE.
DROP DATABASE IF EXISTS rift_or_false_repro;
CREATE DATABASE rift_or_false_repro;
USE rift_or_false_repro;
CREATE TABLE t1 (c1 INT NOT NULL, c2 VARCHAR(255) NOT NULL, c3 VARCHAR(255) NULL, c4 INT NULL, c5 DATE NOT NULL, c6 VARCHAR(10) NOT NULL, PRIMARY KEY (c1));
CREATE TABLE t2 (c1 INT NOT NULL, c2 INT NOT NULL, c4 VARCHAR(50) NOT NULL, c5 DATE NOT NULL, c6 MEDIUMTEXT NULL, c7 LONGTEXT NULL, c9 LONGBLOB NULL, c11 SET('a','b','c','d') NULL, c13 DATETIME NULL, c14 FLOAT(8,2) NULL, c15 DOUBLE(12,4) NULL, PRIMARY KEY (c1));
CREATE TABLE t3 (c1 INT NOT NULL, c2 INT NOT NULL, c3 INT NOT NULL, c4 YEAR NOT NULL, c5 DATETIME NULL, c6 TINYINT NULL, c7 SMALLINT NULL, c8 MEDIUMINT NULL, c9 BIGINT NULL, c10 LONGTEXT NULL, c11 LONGBLOB NULL, c12 TINYTEXT NULL, c14 SET('x','y','z') NULL, c15 TINYINT(1) NULL, PRIMARY KEY (c1));
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (193, 'sample_qIsQxnvPUGCG9ql2M2FgkcGXgOWJDnId33Q5hwrWWYrK7c4g71p2JOoov7KMl8xOkJ66hA3z9Fu7WFRFJ1q6HuIBIkgXHHkbK3wKr49w4cVTCSgt', 'sample_6', 79, '2026-06-22', 'sample_W');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (292, 'sample_zjQc4shMamfhBZQjtWNrW1n3kQG9uQwjkdYy7PFFD3pj8wqBxLZSuK6GNlLW4STkGk6aGZo3wfxlyakcmeUTL', 'sample_TF1FeYFAuy', 73, '2026-06-28', 'sample_j');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (978, 'sample_35FGei0RfL1uIRrPp4TB8DYbgTTxH6PzuqT0sxKzbPQ2kpE4FGdbvixk6l7LSyeUcE2VC36yj8Zd80ymka9KZGw1LqUL6qDFwOAemxTmK5pdE9mZHbHLmECQ2t6w2ta0NNukujAJeWDFmAeu8x6HRiPGB2P0ImvcnPOkuxFbL', 'sample_penEheD8esv4T75J9sbzpm1pQY07sM8MqY0wgSyHW6KChJuMPHgrO00dyWdS66TPwKvsMipl9mqctQEzOC8HxQ1HiUifqJ8Rxa3WcRpAFg6pUXaQsvSTjcLAeFhOmpFgpzudhKYoQh6mVoq1EyItxpynx9DBe', 23, '2026-05-08', 'sample_k');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (1127, 'sample_eXKLVUkiE0X0KpxEbWzp8xMuXw0lauykjeV2naNHz3RVOO4nPlyKw0e20j61f3RRS09LH7cCKVMr4N3B4YA', 'sample_duBDChImNJKdlajUjd9f7LW', 8, '2026-03-29', 'sample_B');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (1294, 'sample_dNgv1V6WpmbJFn38OxBFxIXEvGorC1Ozybopbux', 'sample_cKsSHqmp4YnKqJMKRvKhtuYba3vDCDkFR5aFRD5URKJBzFHvRsWRqj0FVx0aDXGBtqQXOmy', 51, '2026-03-18', 'sample_l');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (1860, 'sample_qpr1AQSvoG32YMLtcAEHXfvhiKLplOgQwVNrRbjtURXdleYJldlTCauvAC7dIucoS1yPT0whioUXnMY5DskLzPe3xNFBzKC1sSHxFWMvZa8rbr9lees9tCzjWYhd3cD6CRH72Aun20X7NkwFfuznYlVIkBeYo', 'sample_2AjFYYeYwzkGTHAi2bGRcKDIVe5kBbJw0ulKwU6OzqMr89UE0lfzCbOcM4dor84y88qohCezwO06TI6avNLPlicrpg9DUiAOKOPS57BL4d0J54KeODDMErOuDW1LBSSibGnYHWpvhzyrwBelTrresjsEXk9O5HU9N5tip34WWhR5Hjpsrx2JGL7No4YZAE8iBeYKncnEZIPBJtRBoCJLEzsm', 4, '2026-05-22', 'sample_m');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (2278, 'sample_3RhJMxMUqLTaGyKSkX5Q5KXAY8fyPWRbZlKFvlCew7sNmcNEmXGL0kq0RHgevosVmw1snlWwVc7B4OER1eAhF0U2L7HUf0hquxx9OZncB2Z5pRTOjh4xCK03cxUv6Xpnn7aMsUk7VZaRBLYAozmmIaswrSd6NDihlRCwdJEZEc8qReJ6sh9YJMNTDiEto209Yt8v4NXh4WyDRMOKBAAD3jvaLRySKxV4DFtAVUkE', 'sample_Rm8ngUXrJFZAEG8vQWGcw7LmiDD7dcL', 20, '2025-12-15', 'sample_HzO');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (2669, 'sample_wB5SJ8ODmolsUrE6mnYpmY2GEOoIw8Rh0KpxMQyMLk3PUE3cmsh6K07tsm8ERsmp6aK4WqzHrRbeVWV0XeouEEw9KoZJjGnt7vMWkJTVUaWC0T3czIANBabYWjmcMtN5IGUKMfvvIhZbqY0bqEbQKB9W2FonLNyluBI1DKInu6g5zQ', 'sample_MI2G7TbtYCypLp60MCaoW1TrCJsitetTGY8XtqfuFyhtzbDXtJyZtLlCO2wTgmCzvuMzk4LCUUFnAW3hIZPe8bla0kVN0jb00cyzlp8XVaFc4jzKVFzsxe6B42JaJ1s9Tr8al7mdQtLutnwHWRZByuexe4mOAxYKJtlfoOPCtNNr', 89, '2025-08-27', 'sample_E');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (2815, 'sample_tdek8XEvARC8pnlFPh6DlFMcSqbxkccjPEnUdchLQsJVzuAAK7oIVxYt4BNs6dKAhsqg3fPHUvOfYNfHzefBCRvnT4wtbvrvrKVttSrTp6lrXMEgTsymnLwtFxwpuSTdOqdVPH7JtmIZexjKCRLAduHyGBGy0RuNzdjVzwmrptL4mtzyDfI8Q2nT1AJLyvR6zNBzhw0mQddEU2uxOZiAp2adjmAq5epR3mOH4xsDheaXTb', 'sample_XqQXvAq1TIZvroL6K1f2P', 71, '2025-08-26', 'sample_U');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (3172, 'sample_wWqhcWjlZzSxb2NQ4kic37bbVv3nIQpj9S8c3BOUJBPxflE4Ea6eLrlmOv2PRXAo80ChZGsqtvK0kKlz0hSG', 'sample_754a18AF7xODjTYei1UDl9NNtEEHdUzvkqT0gmP', 68, '2025-10-22', 'sample_R');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (3395, 'sample_aOl9y37UNHRRgpBQCPB3G2xS6yzJCgzdmaBwosaIPE5Jketzu8VfCDmRBbAOM8AiEBgplUdecTkr9EdwhuupdaFgAD16d83oUY4sh8QP1j1AYxtQ1Q16jdcKUK0dY28Cue6ZrlQKpv87qCrZYkxynJDhWsw3PiasZlpIYyepeNr8DLseAPFBFFrXkXhK4Nc2iy4k0QzcBwgdnBLaYJ', 'sample_CjuLFHDAfQshiVq9cxCCNNFbrCNdj9vSRJSg5qrnY2CyVWOevOiDFHJ5wnG6sGraRIUrQHlvA3QIEai6uetogfw8XVMDJ7Sv15Z4uY2O9ZUu6e2wcHUUC92AXg3zvcjFNWahWRwhADh7rxbcYMQR60OP7SvBPWpBOF0jcbj8xZaERveFp4Udemv1xgujRoVZkzLPnusiEiZWFmnDsEk3t3JdfkIIwk', 53, '2025-11-27', 'sample_P');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (3813, 'sample_0I3Hk1XvMPHSdkRgdn46p09gcDxufPaXrUiJcXbuCAeczEzD7L6kQt2WZGRVrJiVXoWRsqJYWhnhNrwRPUj84FLbiRzTMVQ6y4eLYa8uM6oZtznnTHb2xROz8pO0WcNxvxOSIh9kIK6emxftHmOQXPH0KCaJLgLQ08Sp6xPN0hksagxKwCgT7RpRujbYxdWes9m9pI5VEOaJ9iBxjPxWMv', 'sample_eGdCQopIX3J0GoXl5AywJCaCAm9a78KDSKag5QD50pD7gvmILdTiEJaoMl4x8WXydzDe5VQfMG', 13, '2026-03-05', 'sample_l');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (4749, 'sample_vNuSLti09RmSZ180tFlWL1bZRWZENtuSOsuXxDVGisL4Kqm', 'sample_b7GpSCN0u3Ph905Jd5srbFnsQR1fKp9euNMaAERujjvy0TZvSi98baz1gA0xn5dmRVt4uG7XWHHPK5q1YZEOBwk5IolqoRPVZC7ssHyZcZgaLa5C38mYlXIQU5JUsZlzAfNOP5Nj33HFt9Fhj5dJEhyIIpjvoDMkQ6PpZueuKtpahyfuz8APCo0GDN7Bn7jU6PSoiqQBXxhkeRs4p', 32, '2025-10-28', 'sample_F');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (4863, 'sample_qd01plTUCv1J1ZQ2tKLAh5y3ScdxACLKVnDjpY7j4A3jjK34VPSqgsYW7Eu5quVDP4sq8zxqHZjFoEaCXfrcTtLYdL4HKLcWWMgS3cNzMGb1yPkl8Q3d6Zay87FndDW689leqPIlgxzvxxZXyBXKlQ3Dbjk48BbU3A', 'sample_8tYzkY2U81No6mZY189qloHCfOPDfRe0sHKY2GzW0tXdI1IWYFv63CizTejNQeLA4yriWQ9KJlD0x4pQWxZvTaGpua75WPyAVrO6eIva9GWIdT7q8ywGUHynCY11792MjAUVOQpiytCXcHnCCCytgIbXKdpl17MrZichSG4wjAuT5MwZV0m7lHqbw4rNI0N4fjIytQtVoxjBPW9HLhOhzLP1oOiozLfdR5hBFRkY9uRmcTTe', 85, '2025-07-28', 'sample_6');
INSERT INTO t1 (c1, c2, c3, c4, c5, c6) VALUES (4973, 'sample_BUTGY8FX9XLTsC5PZ0MUu4Yh6SZpnIJ1siFIhZWIMNwC6NpFxX8eM2ShrPXTJvkOMYMhimBLx2kI8PpkUZtobDCdNu5wDoWqO4UsOpiDFClQAxXM2zz5XJd74PDJh5fcF7Pn2A3KZB2wOj2sz4Ho7MbYRh8yEuZaEvKygDamqnHZRkoehpL6b7vlH4uXONLhAxXTm3gsIf77bD4EZnJyuLKUIMJw7pAZhLkn3WknMTWZ4AQQcK3mC', 'sample_Sayg0DbgqFPYyj5x4KoBk1ACf676VwK6wu9gVIllz7zIjBMNWY117RJWtArwqKUPuAXnS7TTFYo9GChlGoWA5tAAPdIqsJMC6Dj7UoPNpoUt2L60f2NTiqTthfz3lb0SZyUKBjuR65BP6CnB', 4, '2026-06-17', 'sample_q');
INSERT INTO t2 (c1, c2, c4, c5, c6, c7, c9, c11, c13, c14, c15) VALUES (3161, 9480, 'sample_XQOJaYEsKtGhnErHea52itU1j', '2026-01-06', 'sample_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', 'sample_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', X'd6b179c2a2c8a6ef84b0daa5cb96', 'a,b,c,d', '2026-03-10 13:38:54', 99.26e0, 51.9e0);
INSERT INTO t2 (c1, c2, c4, c5, c6, c7, c9, c11, c13, c14, c15) VALUES (4844, 6817, 'sample_lzek', '2025-09-26', 'sample_p4zwSD295fFK', 'sample_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', X'd5b41e25d294e390a5e895b743e29288cfb82c0e1d', 'a,b,c,d', '2025-11-10 18:41:19', 72.92e0, 95.33e0);
INSERT INTO t2 (c1, c2, c4, c5, c6, c7, c9, c11, c13, c14, c15) VALUES (7030, 2815, 'sample_f4cGGPbE0suwuXY087WAck1GSClFwHo', '2026-02-24', 'sample_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', 'sample_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', X'e398bddb8fe9a988e88c8d6ae18895d9a2d7a5', 'a,c,d', '2025-07-27 09:09:22', 19.75e0, 42.77e0);
INSERT INTO t2 (c1, c2, c4, c5, c6, c7, c9, c11, c13, c14, c15) VALUES (7134, 292, 'sample_J', '2026-05-02', 'sample_JRZKtFmyKE7Nw38U5vwhmA2urqSqA284Zl', 'sample_XT3cv5wklmGm7jDr7stFurMNIybyfoDktllMns6auJKedf7Di64IczyeKkeiqzkdblhXFi94x8bZZcXNUORxqOXduk9UIP23xcsFwdtA93PzWFhONEAOYdog1GIl0IpzhOCiFMOf398WCM65uqw792i5IOOP0Hz94l0adH4AELGt0SAJnitFF5o9KDw40MeAJ5c5RthjVDF2rqDxr3daezcFpuZPN76YaIQRzGsMfLbHwXRWcXYpEezOImHSRIiR4M5n8SDfG91KRp8lCQCFoV6INwOI5fcy0rT7OFM3D5NuB2F0Sxq2alf6I4DE3uPLkmEOWCPc9GCJO', X'19c8911bd791dcaecda5ea8cb035d6b8d3a73cd3b35eda8b2dd584', 'a,b,c,d', '2026-02-02 02:55:03', 4.12e0, 66.83e0);
CREATE INDEX idx_t1_c6 ON t1 (c6);
-- Original query: returns 0 rows but uses a complex plan.
EXPLAIN SELECT VARIANCE(sq1.col_1) AS col_1, sq1.col_4 AS col_2, (SELECT (t5.c4 + t5.c1) AS col_1 FROM t2 AS t4 LEFT JOIN t1 AS t5 ON ((((t4.c4 <> t5.c3) OR (t4.c2 <> t5.c4)) OR (t4.c2 >= t5.c1)) AND (NOT t4.c6 LIKE '%sample_74%')) ORDER BY t5.c1 ASC LIMIT 1) AS col_3, sq1.col_1 AS col_4 FROM (SELECT LEAD(sq2.col_4) OVER (ORDER BY sq2.col_3 ASC) AS col_1, CAST(sq2.col_4 / sq2.col_4 AS SIGNED) AS col_2, RTRIM('sample_17') AS col_3, TAN(sq2.col_4) AS col_4 FROM (SELECT MAX(t3.c6) AS col_1, t3.c11 AS col_2, (NOT t3.c9 BETWEEN 25 AND 28 AND (t3.c9 > 93)) AS col_3, t3.c8 AS col_4, DEGREES(t3.c7) AS col_5 FROM t3 AS t3 WHERE (((t3.c10 <> 'sample_82') AND (t3.c6 >= 9)) AND (t3.c1 < 73)) GROUP BY t3.c11, (NOT t3.c9 BETWEEN 25 AND 28 AND (t3.c9 > 93)), t3.c9, t3.c8, DEGREES(t3.c7), t3.c7 ORDER BY col_3 DESC) AS sq2 WHERE ((sq2.col_3 = FALSE) AND NOT sq2.col_5 BETWEEN 5 AND 36)) AS sq1 WHERE ((((EXISTS(SELECT t6.c2 AS col_1 FROM t1 AS t6 CROSS JOIN t2 AS t7 ON ((((t6.c4 > t7.c15) OR t6.c5 IN (SELECT t8.c5 AS col_1 FROM t1 AS t8 WHERE (t8.c3 = 'sample_1'))) AND (t6.c5 = t7.c13)) AND (t7.c6 = 'sample_12')) WHERE ((EXISTS(SELECT t15.c12 AS col_1 FROM t1 AS t10 RIGHT JOIN (SELECT DAYNAME(t13.c5) AS col_1, SUM(t13.c6) AS col_2, t13.c7 AS col_3 FROM t1 AS t12 CROSS JOIN t3 AS t13 ON (NOT ((t12.c4 <= t13.c3)) AND NOT t13.c8 IS NULL) WHERE (t13.c3 < 25) GROUP BY DAYNAME(t13.c5), t13.c5, t13.c7 HAVING ((col_2 = 59) AND (col_2 <> 87)) ORDER BY col_3 ASC, col_2 ASC) AS sq11 ON ((NOT sq11.col_1 IN (SELECT UPPER(t14.c3) AS col_1 FROM t1 AS t14) AND (sq11.col_1 <> 'sample_15')) AND (t10.c3 <> 'sample_20')) CROSS JOIN t3 AS t15 ON (t10.c1 <> t15.c7) WHERE ((sq11.col_1 = 'sample_96') AND (t15.c12 = 'sample_53')) LIMIT 49) OR NOT t6.c1 IS NULL) OR t7.c13 BETWEEN '2023-01-01 00:00:00' AND '2023-12-31 23:59:59')) AND EXISTS(SELECT ACOS(t16.c1) AS col_1 FROM t3 AS t16 LEFT JOIN t1 AS t17 ON (t16.c9 >= t17.c1) CROSS JOIN (SELECT sq19.col_3 AS col_1, (sq19.col_5 * sq19.col_5) AS col_2, ((sq19.col_5 > 48) OR sq19.col_2 BETWEEN 14 AND 22) AS col_3, LAG(sq19.col_5) OVER (ORDER BY sq19.col_2 DESC) AS col_4 FROM (SELECT t22.c5 AS col_1, (t21.c9 * t22.c14) AS col_2, (t21.c7 + 8) AS col_3, t22.c9 AS col_4, (t20.c1 + 7) AS col_5 FROM t1 AS t20 CROSS JOIN t3 AS t21 ON ((((t20.c4 <> t21.c15) AND (t20.c1 < t21.c1)) AND (NOT t20.c6 LIKE 'sample_89')) AND (t20.c4 > t21.c3)) INNER JOIN t2 AS t22 ON (t21.c6 >= t22.c2) WHERE (((t21.c9 >= 39) AND t20.c3 IS NULL) OR (t21.c15 < 70)) ORDER BY t20.c2 ASC) AS sq19 WHERE ((((NOT sq19.col_2 IN (SELECT ABS(t23.c1) AS col_1 FROM t1 AS t23 WHERE ((NOT t23.c1 BETWEEN 2 AND 44 AND (NOT REGEXP_LIKE(t23.c2, '.*[0-9]{2}.*'))) AND (t23.c4 <> 78))) AND sq19.col_1 IN (SELECT t26.c5 AS col_1 FROM t3 AS t24 CROSS JOIN t2 AS t25 ON NOT ((t25.c6 = 'sample_29')) INNER JOIN t1 AS t26 ON (((t24.c3 > 11) AND (t24.c12 <> t26.c6)) OR (t24.c7 > t26.c1)) WHERE (t25.c14 < 63))) AND sq19.col_3 BETWEEN 18 AND 55) OR sq19.col_1 IN (SELECT t27.c5 AS col_1 FROM t3 AS t27 WHERE (((t27.c9 > 36) AND (t27.c1 < 70)) OR (t27.c1 = 17)) ORDER BY t27.c4 DESC)) OR (sq19.col_1 = '2023-01-01'))) AS sq18 ON (t16.c15 > 77) WHERE (t17.c3 LIKE '%sample_17'))) AND sq1.col_3 IN (SELECT (t29.c15 * 27) AS col_1 FROM t1 AS t28 LEFT JOIN t2 AS t29 ON ((t28.c6 <> t29.c4) AND (t28.c1 < t29.c15)) CROSS JOIN t3 AS t30 ON (t30.c4 IN (SELECT t31.c4 AS col_1 FROM t1 AS t31 WHERE ((t31.c4 BETWEEN 18 AND 21 AND EXISTS(SELECT t32.c9 AS col_1 FROM t2 AS t32 LEFT JOIN t3 AS t33 ON ((t32.c7 = t33.c12) AND (t32.c5 <> t33.c5)) INNER JOIN t1 AS t34 ON (((t32.c7 <> t34.c2) AND (t32.c1 >= t34.c1)) AND (t34.c4 <= 74)) WHERE ((NOT t32.c13 BETWEEN '2023-01-01 00:00:00' AND '2023-12-31 23:59:59' OR (t34.c3 = 'sample_34')) AND (NOT REGEXP_LIKE(t33.c12, '.*[0-9]{2}.*'))))) AND (t31.c6 <> 'sample_92'))) OR (t29.c11 = t30.c14)) WHERE ((t30.c6 BETWEEN 31 AND 36 AND (t29.c7 <> 'sample_47')) AND (t29.c6 <> 'sample_82')))) AND (sq1.col_2 > 75)) AND sq1.col_1 IN (SELECT CEIL(t35.c1) AS col_1 FROM t1 AS t35 INNER JOIN t3 AS t36 ON (NOT t35.c6 LIKE 'sample_47%') WHERE t36.c2 IN (SELECT t37.c14 AS col_1 FROM t2 AS t37 WHERE ((t37.c7 <> 'sample_60') OR (t37.c7 = 'sample_14'))) ORDER BY t36.c8 DESC)) GROUP BY sq1.col_4, sq1.col_1 ORDER BY col_4 ASC;
SELECT VARIANCE(sq1.col_1) AS col_1, sq1.col_4 AS col_2, (SELECT (t5.c4 + t5.c1) AS col_1 FROM t2 AS t4 LEFT JOIN t1 AS t5 ON ((((t4.c4 <> t5.c3) OR (t4.c2 <> t5.c4)) OR (t4.c2 >= t5.c1)) AND (NOT t4.c6 LIKE '%sample_74%')) ORDER BY t5.c1 ASC LIMIT 1) AS col_3, sq1.col_1 AS col_4 FROM (SELECT LEAD(sq2.col_4) OVER (ORDER BY sq2.col_3 ASC) AS col_1, CAST(sq2.col_4 / sq2.col_4 AS SIGNED) AS col_2, RTRIM('sample_17') AS col_3, TAN(sq2.col_4) AS col_4 FROM (SELECT MAX(t3.c6) AS col_1, t3.c11 AS col_2, (NOT t3.c9 BETWEEN 25 AND 28 AND (t3.c9 > 93)) AS col_3, t3.c8 AS col_4, DEGREES(t3.c7) AS col_5 FROM t3 AS t3 WHERE (((t3.c10 <> 'sample_82') AND (t3.c6 >= 9)) AND (t3.c1 < 73)) GROUP BY t3.c11, (NOT t3.c9 BETWEEN 25 AND 28 AND (t3.c9 > 93)), t3.c9, t3.c8, DEGREES(t3.c7), t3.c7 ORDER BY col_3 DESC) AS sq2 WHERE ((sq2.col_3 = FALSE) AND NOT sq2.col_5 BETWEEN 5 AND 36)) AS sq1 WHERE ((((EXISTS(SELECT t6.c2 AS col_1 FROM t1 AS t6 CROSS JOIN t2 AS t7 ON ((((t6.c4 > t7.c15) OR t6.c5 IN (SELECT t8.c5 AS col_1 FROM t1 AS t8 WHERE (t8.c3 = 'sample_1'))) AND (t6.c5 = t7.c13)) AND (t7.c6 = 'sample_12')) WHERE ((EXISTS(SELECT t15.c12 AS col_1 FROM t1 AS t10 RIGHT JOIN (SELECT DAYNAME(t13.c5) AS col_1, SUM(t13.c6) AS col_2, t13.c7 AS col_3 FROM t1 AS t12 CROSS JOIN t3 AS t13 ON (NOT ((t12.c4 <= t13.c3)) AND NOT t13.c8 IS NULL) WHERE (t13.c3 < 25) GROUP BY DAYNAME(t13.c5), t13.c5, t13.c7 HAVING ((col_2 = 59) AND (col_2 <> 87)) ORDER BY col_3 ASC, col_2 ASC) AS sq11 ON ((NOT sq11.col_1 IN (SELECT UPPER(t14.c3) AS col_1 FROM t1 AS t14) AND (sq11.col_1 <> 'sample_15')) AND (t10.c3 <> 'sample_20')) CROSS JOIN t3 AS t15 ON (t10.c1 <> t15.c7) WHERE ((sq11.col_1 = 'sample_96') AND (t15.c12 = 'sample_53')) LIMIT 49) OR NOT t6.c1 IS NULL) OR t7.c13 BETWEEN '2023-01-01 00:00:00' AND '2023-12-31 23:59:59')) AND EXISTS(SELECT ACOS(t16.c1) AS col_1 FROM t3 AS t16 LEFT JOIN t1 AS t17 ON (t16.c9 >= t17.c1) CROSS JOIN (SELECT sq19.col_3 AS col_1, (sq19.col_5 * sq19.col_5) AS col_2, ((sq19.col_5 > 48) OR sq19.col_2 BETWEEN 14 AND 22) AS col_3, LAG(sq19.col_5) OVER (ORDER BY sq19.col_2 DESC) AS col_4 FROM (SELECT t22.c5 AS col_1, (t21.c9 * t22.c14) AS col_2, (t21.c7 + 8) AS col_3, t22.c9 AS col_4, (t20.c1 + 7) AS col_5 FROM t1 AS t20 CROSS JOIN t3 AS t21 ON ((((t20.c4 <> t21.c15) AND (t20.c1 < t21.c1)) AND (NOT t20.c6 LIKE 'sample_89')) AND (t20.c4 > t21.c3)) INNER JOIN t2 AS t22 ON (t21.c6 >= t22.c2) WHERE (((t21.c9 >= 39) AND t20.c3 IS NULL) OR (t21.c15 < 70)) ORDER BY t20.c2 ASC) AS sq19 WHERE ((((NOT sq19.col_2 IN (SELECT ABS(t23.c1) AS col_1 FROM t1 AS t23 WHERE ((NOT t23.c1 BETWEEN 2 AND 44 AND (NOT REGEXP_LIKE(t23.c2, '.*[0-9]{2}.*'))) AND (t23.c4 <> 78))) AND sq19.col_1 IN (SELECT t26.c5 AS col_1 FROM t3 AS t24 CROSS JOIN t2 AS t25 ON NOT ((t25.c6 = 'sample_29')) INNER JOIN t1 AS t26 ON (((t24.c3 > 11) AND (t24.c12 <> t26.c6)) OR (t24.c7 > t26.c1)) WHERE (t25.c14 < 63))) AND sq19.col_3 BETWEEN 18 AND 55) OR sq19.col_1 IN (SELECT t27.c5 AS col_1 FROM t3 AS t27 WHERE (((t27.c9 > 36) AND (t27.c1 < 70)) OR (t27.c1 = 17)) ORDER BY t27.c4 DESC)) OR (sq19.col_1 = '2023-01-01'))) AS sq18 ON (t16.c15 > 77) WHERE (t17.c3 LIKE '%sample_17'))) AND sq1.col_3 IN (SELECT (t29.c15 * 27) AS col_1 FROM t1 AS t28 LEFT JOIN t2 AS t29 ON ((t28.c6 <> t29.c4) AND (t28.c1 < t29.c15)) CROSS JOIN t3 AS t30 ON (t30.c4 IN (SELECT t31.c4 AS col_1 FROM t1 AS t31 WHERE ((t31.c4 BETWEEN 18 AND 21 AND EXISTS(SELECT t32.c9 AS col_1 FROM t2 AS t32 LEFT JOIN t3 AS t33 ON ((t32.c7 = t33.c12) AND (t32.c5 <> t33.c5)) INNER JOIN t1 AS t34 ON (((t32.c7 <> t34.c2) AND (t32.c1 >= t34.c1)) AND (t34.c4 <= 74)) WHERE ((NOT t32.c13 BETWEEN '2023-01-01 00:00:00' AND '2023-12-31 23:59:59' OR (t34.c3 = 'sample_34')) AND (NOT REGEXP_LIKE(t33.c12, '.*[0-9]{2}.*'))))) AND (t31.c6 <> 'sample_92'))) OR (t29.c11 = t30.c14)) WHERE ((t30.c6 BETWEEN 31 AND 36 AND (t29.c7 <> 'sample_47')) AND (t29.c6 <> 'sample_82')))) AND (sq1.col_2 > 75)) AND sq1.col_1 IN (SELECT CEIL(t35.c1) AS col_1 FROM t1 AS t35 INNER JOIN t3 AS t36 ON (NOT t35.c6 LIKE 'sample_47%') WHERE t36.c2 IN (SELECT t37.c14 AS col_1 FROM t2 AS t37 WHERE ((t37.c7 <> 'sample_60') OR (t37.c7 = 'sample_14'))) ORDER BY t36.c8 DESC)) GROUP BY sq1.col_4, sq1.col_1 ORDER BY col_4 ASC;
-- Mutated query: semantically equivalent; only adds OR FALSE before GROUP BY.
EXPLAIN SELECT VARIANCE(sq1.col_1) AS col_1, sq1.col_4 AS col_2, (SELECT (t5.c4 + t5.c1) AS col_1 FROM t2 AS t4 LEFT JOIN t1 AS t5 ON ((((t4.c4 <> t5.c3) OR (t4.c2 <> t5.c4)) OR (t4.c2 >= t5.c1)) AND (NOT t4.c6 LIKE '%sample_74%')) ORDER BY t5.c1 ASC LIMIT 1) AS col_3, sq1.col_1 AS col_4 FROM (SELECT LEAD(sq2.col_4) OVER (ORDER BY sq2.col_3 ASC) AS col_1, CAST(sq2.col_4 / sq2.col_4 AS SIGNED) AS col_2, RTRIM('sample_17') AS col_3, TAN(sq2.col_4) AS col_4 FROM (SELECT MAX(t3.c6) AS col_1, t3.c11 AS col_2, (NOT t3.c9 BETWEEN 25 AND 28 AND (t3.c9 > 93)) AS col_3, t3.c8 AS col_4, DEGREES(t3.c7) AS col_5 FROM t3 AS t3 WHERE (((t3.c10 <> 'sample_82') AND (t3.c6 >= 9)) AND (t3.c1 < 73)) GROUP BY t3.c11, (NOT t3.c9 BETWEEN 25 AND 28 AND (t3.c9 > 93)), t3.c9, t3.c8, DEGREES(t3.c7), t3.c7 ORDER BY col_3 DESC) AS sq2 WHERE ((sq2.col_3 = FALSE) AND NOT sq2.col_5 BETWEEN 5 AND 36)) AS sq1 WHERE ((((EXISTS(SELECT t6.c2 AS col_1 FROM t1 AS t6 CROSS JOIN t2 AS t7 ON ((((t6.c4 > t7.c15) OR t6.c5 IN (SELECT t8.c5 AS col_1 FROM t1 AS t8 WHERE (t8.c3 = 'sample_1'))) AND (t6.c5 = t7.c13)) AND (t7.c6 = 'sample_12')) WHERE ((EXISTS(SELECT t15.c12 AS col_1 FROM t1 AS t10 RIGHT JOIN (SELECT DAYNAME(t13.c5) AS col_1, SUM(t13.c6) AS col_2, t13.c7 AS col_3 FROM t1 AS t12 CROSS JOIN t3 AS t13 ON (NOT ((t12.c4 <= t13.c3)) AND NOT t13.c8 IS NULL) WHERE (t13.c3 < 25) GROUP BY DAYNAME(t13.c5), t13.c5, t13.c7 HAVING ((col_2 = 59) AND (col_2 <> 87)) ORDER BY col_3 ASC, col_2 ASC) AS sq11 ON ((NOT sq11.col_1 IN (SELECT UPPER(t14.c3) AS col_1 FROM t1 AS t14) AND (sq11.col_1 <> 'sample_15')) AND (t10.c3 <> 'sample_20')) CROSS JOIN t3 AS t15 ON (t10.c1 <> t15.c7) WHERE ((sq11.col_1 = 'sample_96') AND (t15.c12 = 'sample_53')) LIMIT 49) OR NOT t6.c1 IS NULL) OR t7.c13 BETWEEN '2023-01-01 00:00:00' AND '2023-12-31 23:59:59')) AND EXISTS(SELECT ACOS(t16.c1) AS col_1 FROM t3 AS t16 LEFT JOIN t1 AS t17 ON (t16.c9 >= t17.c1) CROSS JOIN (SELECT sq19.col_3 AS col_1, (sq19.col_5 * sq19.col_5) AS col_2, ((sq19.col_5 > 48) OR sq19.col_2 BETWEEN 14 AND 22) AS col_3, LAG(sq19.col_5) OVER (ORDER BY sq19.col_2 DESC) AS col_4 FROM (SELECT t22.c5 AS col_1, (t21.c9 * t22.c14) AS col_2, (t21.c7 + 8) AS col_3, t22.c9 AS col_4, (t20.c1 + 7) AS col_5 FROM t1 AS t20 CROSS JOIN t3 AS t21 ON ((((t20.c4 <> t21.c15) AND (t20.c1 < t21.c1)) AND (NOT t20.c6 LIKE 'sample_89')) AND (t20.c4 > t21.c3)) INNER JOIN t2 AS t22 ON (t21.c6 >= t22.c2) WHERE (((t21.c9 >= 39) AND t20.c3 IS NULL) OR (t21.c15 < 70)) ORDER BY t20.c2 ASC) AS sq19 WHERE ((((NOT sq19.col_2 IN (SELECT ABS(t23.c1) AS col_1 FROM t1 AS t23 WHERE ((NOT t23.c1 BETWEEN 2 AND 44 AND (NOT REGEXP_LIKE(t23.c2, '.*[0-9]{2}.*'))) AND (t23.c4 <> 78))) AND sq19.col_1 IN (SELECT t26.c5 AS col_1 FROM t3 AS t24 CROSS JOIN t2 AS t25 ON NOT ((t25.c6 = 'sample_29')) INNER JOIN t1 AS t26 ON (((t24.c3 > 11) AND (t24.c12 <> t26.c6)) OR (t24.c7 > t26.c1)) WHERE (t25.c14 < 63))) AND sq19.col_3 BETWEEN 18 AND 55) OR sq19.col_1 IN (SELECT t27.c5 AS col_1 FROM t3 AS t27 WHERE (((t27.c9 > 36) AND (t27.c1 < 70)) OR (t27.c1 = 17)) ORDER BY t27.c4 DESC)) OR (sq19.col_1 = '2023-01-01'))) AS sq18 ON (t16.c15 > 77) WHERE (t17.c3 LIKE '%sample_17'))) AND sq1.col_3 IN (SELECT (t29.c15 * 27) AS col_1 FROM t1 AS t28 LEFT JOIN t2 AS t29 ON ((t28.c6 <> t29.c4) AND (t28.c1 < t29.c15)) CROSS JOIN t3 AS t30 ON (t30.c4 IN (SELECT t31.c4 AS col_1 FROM t1 AS t31 WHERE ((t31.c4 BETWEEN 18 AND 21 AND EXISTS(SELECT t32.c9 AS col_1 FROM t2 AS t32 LEFT JOIN t3 AS t33 ON ((t32.c7 = t33.c12) AND (t32.c5 <> t33.c5)) INNER JOIN t1 AS t34 ON (((t32.c7 <> t34.c2) AND (t32.c1 >= t34.c1)) AND (t34.c4 <= 74)) WHERE ((NOT t32.c13 BETWEEN '2023-01-01 00:00:00' AND '2023-12-31 23:59:59' OR (t34.c3 = 'sample_34')) AND (NOT REGEXP_LIKE(t33.c12, '.*[0-9]{2}.*'))))) AND (t31.c6 <> 'sample_92'))) OR (t29.c11 = t30.c14)) WHERE ((t30.c6 BETWEEN 31 AND 36 AND (t29.c7 <> 'sample_47')) AND (t29.c6 <> 'sample_82')))) AND (sq1.col_2 > 75)) AND sq1.col_1 IN (SELECT CEIL(t35.c1) AS col_1 FROM t1 AS t35 INNER JOIN t3 AS t36 ON (NOT t35.c6 LIKE 'sample_47%') WHERE t36.c2 IN (SELECT t37.c14 AS col_1 FROM t2 AS t37 WHERE ((t37.c7 <> 'sample_60') OR (t37.c7 = 'sample_14'))) ORDER BY t36.c8 DESC)) OR FALSE GROUP BY sq1.col_4, sq1.col_1 ORDER BY col_4 ASC;
SELECT VARIANCE(sq1.col_1) AS col_1, sq1.col_4 AS col_2, (SELECT (t5.c4 + t5.c1) AS col_1 FROM t2 AS t4 LEFT JOIN t1 AS t5 ON ((((t4.c4 <> t5.c3) OR (t4.c2 <> t5.c4)) OR (t4.c2 >= t5.c1)) AND (NOT t4.c6 LIKE '%sample_74%')) ORDER BY t5.c1 ASC LIMIT 1) AS col_3, sq1.col_1 AS col_4 FROM (SELECT LEAD(sq2.col_4) OVER (ORDER BY sq2.col_3 ASC) AS col_1, CAST(sq2.col_4 / sq2.col_4 AS SIGNED) AS col_2, RTRIM('sample_17') AS col_3, TAN(sq2.col_4) AS col_4 FROM (SELECT MAX(t3.c6) AS col_1, t3.c11 AS col_2, (NOT t3.c9 BETWEEN 25 AND 28 AND (t3.c9 > 93)) AS col_3, t3.c8 AS col_4, DEGREES(t3.c7) AS col_5 FROM t3 AS t3 WHERE (((t3.c10 <> 'sample_82') AND (t3.c6 >= 9)) AND (t3.c1 < 73)) GROUP BY t3.c11, (NOT t3.c9 BETWEEN 25 AND 28 AND (t3.c9 > 93)), t3.c9, t3.c8, DEGREES(t3.c7), t3.c7 ORDER BY col_3 DESC) AS sq2 WHERE ((sq2.col_3 = FALSE) AND NOT sq2.col_5 BETWEEN 5 AND 36)) AS sq1 WHERE ((((EXISTS(SELECT t6.c2 AS col_1 FROM t1 AS t6 CROSS JOIN t2 AS t7 ON ((((t6.c4 > t7.c15) OR t6.c5 IN (SELECT t8.c5 AS col_1 FROM t1 AS t8 WHERE (t8.c3 = 'sample_1'))) AND (t6.c5 = t7.c13)) AND (t7.c6 = 'sample_12')) WHERE ((EXISTS(SELECT t15.c12 AS col_1 FROM t1 AS t10 RIGHT JOIN (SELECT DAYNAME(t13.c5) AS col_1, SUM(t13.c6) AS col_2, t13.c7 AS col_3 FROM t1 AS t12 CROSS JOIN t3 AS t13 ON (NOT ((t12.c4 <= t13.c3)) AND NOT t13.c8 IS NULL) WHERE (t13.c3 < 25) GROUP BY DAYNAME(t13.c5), t13.c5, t13.c7 HAVING ((col_2 = 59) AND (col_2 <> 87)) ORDER BY col_3 ASC, col_2 ASC) AS sq11 ON ((NOT sq11.col_1 IN (SELECT UPPER(t14.c3) AS col_1 FROM t1 AS t14) AND (sq11.col_1 <> 'sample_15')) AND (t10.c3 <> 'sample_20')) CROSS JOIN t3 AS t15 ON (t10.c1 <> t15.c7) WHERE ((sq11.col_1 = 'sample_96') AND (t15.c12 = 'sample_53')) LIMIT 49) OR NOT t6.c1 IS NULL) OR t7.c13 BETWEEN '2023-01-01 00:00:00' AND '2023-12-31 23:59:59')) AND EXISTS(SELECT ACOS(t16.c1) AS col_1 FROM t3 AS t16 LEFT JOIN t1 AS t17 ON (t16.c9 >= t17.c1) CROSS JOIN (SELECT sq19.col_3 AS col_1, (sq19.col_5 * sq19.col_5) AS col_2, ((sq19.col_5 > 48) OR sq19.col_2 BETWEEN 14 AND 22) AS col_3, LAG(sq19.col_5) OVER (ORDER BY sq19.col_2 DESC) AS col_4 FROM (SELECT t22.c5 AS col_1, (t21.c9 * t22.c14) AS col_2, (t21.c7 + 8) AS col_3, t22.c9 AS col_4, (t20.c1 + 7) AS col_5 FROM t1 AS t20 CROSS JOIN t3 AS t21 ON ((((t20.c4 <> t21.c15) AND (t20.c1 < t21.c1)) AND (NOT t20.c6 LIKE 'sample_89')) AND (t20.c4 > t21.c3)) INNER JOIN t2 AS t22 ON (t21.c6 >= t22.c2) WHERE (((t21.c9 >= 39) AND t20.c3 IS NULL) OR (t21.c15 < 70)) ORDER BY t20.c2 ASC) AS sq19 WHERE ((((NOT sq19.col_2 IN (SELECT ABS(t23.c1) AS col_1 FROM t1 AS t23 WHERE ((NOT t23.c1 BETWEEN 2 AND 44 AND (NOT REGEXP_LIKE(t23.c2, '.*[0-9]{2}.*'))) AND (t23.c4 <> 78))) AND sq19.col_1 IN (SELECT t26.c5 AS col_1 FROM t3 AS t24 CROSS JOIN t2 AS t25 ON NOT ((t25.c6 = 'sample_29')) INNER JOIN t1 AS t26 ON (((t24.c3 > 11) AND (t24.c12 <> t26.c6)) OR (t24.c7 > t26.c1)) WHERE (t25.c14 < 63))) AND sq19.col_3 BETWEEN 18 AND 55) OR sq19.col_1 IN (SELECT t27.c5 AS col_1 FROM t3 AS t27 WHERE (((t27.c9 > 36) AND (t27.c1 < 70)) OR (t27.c1 = 17)) ORDER BY t27.c4 DESC)) OR (sq19.col_1 = '2023-01-01'))) AS sq18 ON (t16.c15 > 77) WHERE (t17.c3 LIKE '%sample_17'))) AND sq1.col_3 IN (SELECT (t29.c15 * 27) AS col_1 FROM t1 AS t28 LEFT JOIN t2 AS t29 ON ((t28.c6 <> t29.c4) AND (t28.c1 < t29.c15)) CROSS JOIN t3 AS t30 ON (t30.c4 IN (SELECT t31.c4 AS col_1 FROM t1 AS t31 WHERE ((t31.c4 BETWEEN 18 AND 21 AND EXISTS(SELECT t32.c9 AS col_1 FROM t2 AS t32 LEFT JOIN t3 AS t33 ON ((t32.c7 = t33.c12) AND (t32.c5 <> t33.c5)) INNER JOIN t1 AS t34 ON (((t32.c7 <> t34.c2) AND (t32.c1 >= t34.c1)) AND (t34.c4 <= 74)) WHERE ((NOT t32.c13 BETWEEN '2023-01-01 00:00:00' AND '2023-12-31 23:59:59' OR (t34.c3 = 'sample_34')) AND (NOT REGEXP_LIKE(t33.c12, '.*[0-9]{2}.*'))))) AND (t31.c6 <> 'sample_92'))) OR (t29.c11 = t30.c14)) WHERE ((t30.c6 BETWEEN 31 AND 36 AND (t29.c7 <> 'sample_47')) AND (t29.c6 <> 'sample_82')))) AND (sq1.col_2 > 75)) AND sq1.col_1 IN (SELECT CEIL(t35.c1) AS col_1 FROM t1 AS t35 INNER JOIN t3 AS t36 ON (NOT t35.c6 LIKE 'sample_47%') WHERE t36.c2 IN (SELECT t37.c14 AS col_1 FROM t2 AS t37 WHERE ((t37.c7 <> 'sample_60') OR (t37.c7 = 'sample_14'))) ORDER BY t36.c8 DESC)) OR FALSE GROUP BY sq1.col_4, sq1.col_1 ORDER BY col_4 ASC;
Suggested fix:
Additionally,executing these SQL can observe plan difference:
-- Minimal reproducer for optimizer missed Impossible WHERE detection.
-- Observed on MySQL 9.5.0.
-- The second query only adds redundant OR FALSE.
DROP DATABASE IF EXISTS rift_min_or_false;
CREATE DATABASE rift_min_or_false;
USE rift_min_or_false;
CREATE TABLE t1 (id INT PRIMARY KEY);
CREATE TABLE t2 (c6 VARCHAR(20));
INSERT INTO t1 VALUES (1);
-- t2 is intentionally empty, so the EXISTS predicate is false.
-- Original: returns 0 rows but is not optimized to Impossible WHERE.
EXPLAIN SELECT 1
FROM t1
WHERE EXISTS (SELECT 1 FROM t2 WHERE c6 = 'sample_12');
SELECT 1
FROM t1
WHERE EXISTS (SELECT 1 FROM t2 WHERE c6 = 'sample_12');
-- Mutated: semantically equivalent, only adds OR FALSE, but becomes Impossible WHERE.
EXPLAIN SELECT 1
FROM t1
WHERE EXISTS (SELECT 1 FROM t2 WHERE c6 = 'sample_12') OR FALSE;
SELECT 1
FROM t1
WHERE EXISTS (SELECT 1 FROM t2 WHERE c6 = 'sample_12') OR FALSE;
