EVOLUTION-MANAGER

Edit File: range_vs_index_merge.result

DROP TABLE IF EXISTS t1,t2,t3,t4; DROP DATABASE IF EXISTS world; set names utf8; CREATE DATABASE world; use world; CREATE TABLE Country ( Code char(3) NOT NULL default '', Name char(52) NOT NULL default '', SurfaceArea float(10,2) NOT NULL default '0.00', Population int(11) NOT NULL default '0', Capital int(11) default NULL, PRIMARY KEY (Code), UNIQUE INDEX (Name) ); CREATE TABLE City ( ID int(11) NOT NULL auto_increment, Name char(35) NOT NULL default '', Country char(3) NOT NULL default '', Population int(11) NOT NULL default '0', PRIMARY KEY (ID), INDEX (Population), INDEX (Country) ); CREATE TABLE CountryLanguage ( Country char(3) NOT NULL default '', Language char(30) NOT NULL default '', Percentage float(3,1) NOT NULL default '0.0', PRIMARY KEY (Country, Language), INDEX (Percentage) ); SELECT COUNT(*) FROM Country; COUNT(*) 239 SELECT COUNT(*) FROM City; COUNT(*) 4079 SELECT COUNT(*) FROM CountryLanguage; COUNT(*) 984 CREATE INDEX Name ON City(Name); set session optimizer_switch='index_merge_sort_intersection=off'; EXPLAIN SELECT * FROM City WHERE (Population >= 100000 OR Name LIKE 'P%' OR Population < 100000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City ALL Population,Name NULL NULL NULL 4079 Using where EXPLAIN SELECT * FROM City WHERE (Population >= 100000 OR Name LIKE 'P%') AND Country='CAN' OR (Population < 100000 OR Name Like 'T%') AND Country='ARG'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population,Country,Name Country 3 NULL 104 Using index condition; Using where EXPLAIN SELECT * FROM City WHERE Population < 200000 AND Name LIKE 'P%' AND (Population > 300000 OR Name LIKE 'T%') AND (Population < 100000 OR Name LIKE 'Pa%'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population,Name Name 35 NULL 135 Using index condition; Using where EXPLAIN SELECT * FROM City WHERE Population > 100000 AND Name LIKE 'Aba%' OR Country IN ('CAN', 'ARG') AND ID BETWEEN 120 AND 130 OR Country <= 'ALB' AND Name LIKE 'L%' OR ID BETWEEN 3807 AND 3810; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge PRIMARY,Population,Country,Name Name,PRIMARY,Country 35,4,3 NULL 31 Using sort_union(Name,PRIMARY,Country); Using where EXPLAIN SELECT * FROM City WHERE (Population > 101000 AND Population < 115000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population Population 4 NULL 459 Using index condition EXPLAIN SELECT * FROM City WHERE (Population > 101000 AND Population < 102000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population Population 4 NULL 39 Using index condition EXPLAIN SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'F')); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge Country,Name Name,Country 35,3 NULL 172 Using sort_union(Name,Country); Using where EXPLAIN SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'F')) AND (Population > 101000 AND Population < 115000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge Population,Country,Name Name,Country 35,3 NULL 172 Using sort_union(Name,Country); Using where EXPLAIN SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'F')) AND (Population > 101000 AND Population < 102000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population,Country,Name Population 4 NULL 39 Using index condition; Using where SELECT * FROM City USE INDEX () WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'F')) AND (Population > 101000 AND Population < 115000); ID Name Country Population 403 Catanduva BRA 107761 412 Cachoeirinha BRA 103240 636 Bilbays EGY 113608 637 Mit Ghamr EGY 101801 701 Tarragona ESP 113016 702 Lleida (Lérida) ESP 112207 703 Jaén ESP 109247 704 Ourense (Orense) ESP 109120 705 Mataró ESP 104095 706 Algeciras ESP 103106 707 Marbella ESP 101144 759 Gonder ETH 112249 869 Cabuyao PHL 106630 870 Calapan PHL 105910 873 Cauayan PHL 103952 1844 Cape Breton CAN 114733 1847 Cambridge CAN 109186 2908 Cajamarca PER 108009 3003 Caen FRA 113987 3411 Ceyhan TUR 102412 3571 Calabozo VEN 107146 3786 Cam Ranh VNM 114041 3792 Tartu EST 101246 4002 Carrollton USA 109576 4027 Cape Coral USA 102286 4032 Cambridge USA 101355 SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'F')) AND (Population > 101000 AND Population < 115000); ID Name Country Population 403 Catanduva BRA 107761 412 Cachoeirinha BRA 103240 636 Bilbays EGY 113608 637 Mit Ghamr EGY 101801 701 Tarragona ESP 113016 702 Lleida (Lérida) ESP 112207 703 Jaén ESP 109247 704 Ourense (Orense) ESP 109120 705 Mataró ESP 104095 706 Algeciras ESP 103106 707 Marbella ESP 101144 759 Gonder ETH 112249 869 Cabuyao PHL 106630 870 Calapan PHL 105910 873 Cauayan PHL 103952 1844 Cape Breton CAN 114733 1847 Cambridge CAN 109186 2908 Cajamarca PER 108009 3003 Caen FRA 113987 3411 Ceyhan TUR 102412 3571 Calabozo VEN 107146 3786 Cam Ranh VNM 114041 3792 Tartu EST 101246 4002 Carrollton USA 109576 4027 Cape Coral USA 102286 4032 Cambridge USA 101355 SELECT * FROM City USE INDEX () WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'F')) AND (Population > 101000 AND Population < 102000); ID Name Country Population 637 Mit Ghamr EGY 101801 707 Marbella ESP 101144 3792 Tartu EST 101246 4032 Cambridge USA 101355 SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'F')) AND (Population > 101000 AND Population < 102000); ID Name Country Population 707 Marbella ESP 101144 3792 Tartu EST 101246 4032 Cambridge USA 101355 637 Mit Ghamr EGY 101801 EXPLAIN SELECT * FROM City WHERE (Name < 'Ac'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 13 Using index condition EXPLAIN SELECT * FROM City WHERE (Name < 'Bb'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 208 Using index condition EXPLAIN SELECT * FROM City WHERE (Country > 'A' AND Country < 'B'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Country Country 3 NULL 104 Using index condition EXPLAIN SELECT * FROM City WHERE (Name BETWEEN 'P' AND 'Pb'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 39 Using index condition EXPLAIN SELECT * FROM City WHERE (Name BETWEEN 'P' AND 'S'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 221 Using index condition EXPLAIN SELECT * FROM City WHERE (Population > 101000 AND Population < 110000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population Population 4 NULL 328 Using index condition EXPLAIN SELECT * FROM City WHERE (Population > 103000 AND Population < 104000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population Population 4 NULL 37 Using index condition EXPLAIN SELECT * FROM City WHERE (Name < 'Ac' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'Pb' AND (Population > 101000 AND Population < 110000)); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population,Country,Name Name 35 NULL 52 Using index condition; Using where EXPLAIN SELECT * FROM City WHERE (Name < 'Ac' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'S' AND (Population > 103000 AND Population < 104000)); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge Population,Country,Name Name,Population 35,4 NULL 50 Using sort_union(Name,Population); Using where EXPLAIN SELECT * FROM City WHERE (Name < 'Bb' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'Pb' AND (Population > 101000 AND Population < 110000)); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge Population,Country,Name Country,Name 3,35 NULL 143 Using sort_union(Country,Name); Using where EXPLAIN SELECT * FROM City WHERE (Name < 'Bb' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'S' AND (Population > 103000 AND Population < 104000)); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge Population,Country,Name Country,Population 3,4 NULL 141 Using sort_union(Country,Population); Using where SELECT * FROM City USE INDEX () WHERE (Name < 'Ac' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'Pb' AND (Population > 101000 AND Population < 110000)); ID Name Country Population 65 Abu Dhabi ARE 398695 168 Pabna BGD 103277 189 Parakou BEN 103577 750 Paarl ZAF 105768 2865 Pak Pattan PAK 107800 SELECT * FROM City WHERE (Name < 'Ac' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'Pb' AND (Population > 101000 AND Population < 110000)); ID Name Country Population 65 Abu Dhabi ARE 398695 750 Paarl ZAF 105768 168 Pabna BGD 103277 2865 Pak Pattan PAK 107800 189 Parakou BEN 103577 SELECT * FROM City USE INDEX () WHERE (Name < 'Ac' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'S' AND (Population > 103000 AND Population < 104000)); ID Name Country Population 65 Abu Dhabi ARE 398695 168 Pabna BGD 103277 189 Parakou BEN 103577 1003 Pemalang IDN 103500 2663 Río Bravo MEX 103901 SELECT * FROM City WHERE (Name < 'Ac' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'S' AND (Population > 103000 AND Population < 104000)); ID Name Country Population 65 Abu Dhabi ARE 398695 168 Pabna BGD 103277 189 Parakou BEN 103577 1003 Pemalang IDN 103500 2663 Río Bravo MEX 103901 SELECT * FROM City USE INDEX () WHERE (Name < 'Bb' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'Pb' AND (Population > 101000 AND Population < 110000)); ID Name Country Population 55 Andorra la Vella AND 21189 65 Abu Dhabi ARE 398695 67 al-Ayn ARE 225970 68 Ajman ARE 114395 75 Almirante Brown ARG 538918 85 Avellaneda ARG 353046 96 Bahía Blanca ARG 239810 134 Adelaide AUS 978100 144 Baku AZE 1787800 168 Pabna BGD 103277 189 Parakou BEN 103577 750 Paarl ZAF 105768 2865 Pak Pattan PAK 107800 SELECT * FROM City WHERE (Name < 'Bb' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'Pb' AND (Population > 101000 AND Population < 110000)); ID Name Country Population 55 Andorra la Vella AND 21189 65 Abu Dhabi ARE 398695 67 al-Ayn ARE 225970 68 Ajman ARE 114395 75 Almirante Brown ARG 538918 85 Avellaneda ARG 353046 96 Bahía Blanca ARG 239810 134 Adelaide AUS 978100 144 Baku AZE 1787800 168 Pabna BGD 103277 189 Parakou BEN 103577 750 Paarl ZAF 105768 2865 Pak Pattan PAK 107800 SELECT * FROM City USE INDEX () WHERE (Name < 'Bb' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'S' AND (Population > 103000 AND Population < 104000)); ID Name Country Population 55 Andorra la Vella AND 21189 65 Abu Dhabi ARE 398695 67 al-Ayn ARE 225970 68 Ajman ARE 114395 75 Almirante Brown ARG 538918 85 Avellaneda ARG 353046 96 Bahía Blanca ARG 239810 134 Adelaide AUS 978100 144 Baku AZE 1787800 168 Pabna BGD 103277 189 Parakou BEN 103577 1003 Pemalang IDN 103500 2663 Río Bravo MEX 103901 SELECT * FROM City WHERE (Name < 'Bb' AND (Country > 'A' AND Country < 'B')) OR (Name BETWEEN 'P' AND 'S' AND (Population > 103000 AND Population < 104000)); ID Name Country Population 55 Andorra la Vella AND 21189 65 Abu Dhabi ARE 398695 67 al-Ayn ARE 225970 68 Ajman ARE 114395 75 Almirante Brown ARG 538918 85 Avellaneda ARG 353046 96 Bahía Blanca ARG 239810 134 Adelaide AUS 978100 144 Baku AZE 1787800 168 Pabna BGD 103277 189 Parakou BEN 103577 1003 Pemalang IDN 103500 2663 Río Bravo MEX 103901 EXPLAIN SELECT * FROM City WHERE (ID < 10) OR (ID BETWEEN 100 AND 110); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY PRIMARY 4 NULL 21 Using index condition; Using where EXPLAIN SELECT * FROM City WHERE (ID < 200) OR (ID BETWEEN 100 AND 200); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY PRIMARY 4 NULL 201 Using index condition; Using where EXPLAIN SELECT * FROM City WHERE (ID < 600) OR (ID BETWEEN 900 AND 1500); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City ALL PRIMARY NULL NULL NULL 4079 Using where EXPLAIN SELECT * FROM City WHERE Country > 'A' AND Country < 'ARG'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Country Country 3 NULL 19 Using index condition EXPLAIN SELECT * FROM City WHERE Name LIKE 'H%' OR Name LIKE 'P%' ; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 222 Using index condition; Using where EXPLAIN SELECT * FROM City WHERE Name LIKE 'Ha%' OR Name LIKE 'Pa%' ; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 72 Using index condition; Using where EXPLAIN SELECT * FROM City WHERE ((ID < 10) AND (Name LIKE 'H%' OR (Country > 'A' AND Country < 'ARG'))) OR ((ID BETWEEN 100 AND 110) AND (Name LIKE 'P%' OR (Population > 103000 AND Population < 104000))); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY,Population,Country,Name PRIMARY 4 NULL 21 Using index condition; Using where EXPLAIN SELECT * FROM City WHERE ((ID < 800) AND (Name LIKE 'Ha%' OR (Country > 'A' AND Country < 'ARG'))) OR ((ID BETWEEN 900 AND 1500) AND (Name LIKE 'Pa%' OR (Population > 103000 AND Population < 104000))); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge PRIMARY,Population,Country,Name Name,Country,Population 35,3,4 NULL 128 Using sort_union(Name,Country,Population); Using where EXPLAIN SELECT * FROM City WHERE ((ID < 200) AND (Name LIKE 'Ha%' OR (Country > 'A' AND Country < 'ARG'))) OR ((ID BETWEEN 100 AND 200) AND (Name LIKE 'Pa%' OR (Population > 103000 AND Population < 104000))); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge PRIMARY,Population,Country,Name Name,Country,Population 35,3,4 NULL 128 Using sort_union(Name,Country,Population); Using where SELECT * FROM City USE INDEX () WHERE ((ID < 10) AND (Name LIKE 'H%' OR (Country > 'A' AND Country < 'ARG'))) OR ((ID BETWEEN 100 AND 110) AND (Name LIKE 'P%' OR (Population > 103000 AND Population < 104000))); ID Name Country Population 1 Kabul AFG 1780000 2 Qandahar AFG 237500 3 Herat AFG 186800 4 Mazar-e-Sharif AFG 127800 7 Haag NLD 440900 100 Paraná ARG 207041 102 Posadas ARG 201273 SELECT * FROM City WHERE ((ID < 10) AND (Name LIKE 'H%' OR (Country > 'A' AND Country < 'ARG'))) OR ((ID BETWEEN 100 AND 110) AND (Name LIKE 'P%' OR (Population > 103000 AND Population < 104000))); ID Name Country Population 1 Kabul AFG 1780000 2 Qandahar AFG 237500 3 Herat AFG 186800 4 Mazar-e-Sharif AFG 127800 7 Haag NLD 440900 100 Paraná ARG 207041 102 Posadas ARG 201273 SELECT * FROM City USE INDEX() WHERE ((ID < 800) AND (Name LIKE 'Ha%' OR (Country > 'A' AND Country < 'ARG'))) OR ((ID BETWEEN 900 AND 1500) AND (Name LIKE 'Pa%' OR (Population > 103000 AND Population < 104000))); ID Name Country Population 1 Kabul AFG 1780000 2 Qandahar AFG 237500 3 Herat AFG 186800 4 Mazar-e-Sharif AFG 127800 7 Haag NLD 440900 16 Haarlem NLD 148772 25 Haarlemmermeer NLD 110722 33 Willemstad ANT 2345 34 Tirana ALB 270000 55 Andorra la Vella AND 21189 56 Luanda AGO 2022000 57 Huambo AGO 163100 58 Lobito AGO 130000 59 Benguela AGO 128300 60 Namibe AGO 118200 61 South Hill AIA 961 62 The Valley AIA 595 64 Dubai ARE 669181 65 Abu Dhabi ARE 398695 66 Sharja ARE 320095 67 al-Ayn ARE 225970 68 Ajman ARE 114395 129 Oranjestad ABW 29034 191 Hamilton BMU 1200 528 Hartlepool GBR 92000 529 Halifax GBR 91069 914 Sekondi-Takoradi GHA 103653 943 Palembang IDN 1222764 950 Padang IDN 534474 983 Palu IDN 142800 984 Pasuruan IDN 134019 991 Pangkal Pinang IDN 124000 1003 Pemalang IDN 103500 1004 Klaten IDN 103300 1007 Palangka Raya IDN 99693 1020 Padang Sidempuan IDN 91200 1045 Patna IND 917243 1114 Panihati IND 275990 1129 Patiala IND 238368 1142 Panipat IND 215218 1159 Parbhani IND 190255 1231 Pali IND 136842 1263 Pathankot IND 123930 1265 Palghat (Palakkad) IND 123289 1293 Pallavaram IND 111866 1319 Tellicherry (Thalassery) IND 103579 1339 Palayankottai IND 97662 1345 Patan IND 96109 1436 Marv Dasht IRN 103579 1468 Palermo ITA 683794 1478 Padova ITA 211391 1484 Parma ITA 168717 SELECT * FROM City WHERE ((ID < 800) AND (Name LIKE 'Ha%' OR (Country > 'A' AND Country < 'ARG'))) OR ((ID BETWEEN 900 AND 1500) AND (Name LIKE 'Pa%' OR (Population > 103000 AND Population < 104000))); ID Name Country Population 1 Kabul AFG 1780000 2 Qandahar AFG 237500 3 Herat AFG 186800 4 Mazar-e-Sharif AFG 127800 7 Haag NLD 440900 16 Haarlem NLD 148772 25 Haarlemmermeer NLD 110722 33 Willemstad ANT 2345 34 Tirana ALB 270000 55 Andorra la Vella AND 21189 56 Luanda AGO 2022000 57 Huambo AGO 163100 58 Lobito AGO 130000 59 Benguela AGO 128300 60 Namibe AGO 118200 61 South Hill AIA 961 62 The Valley AIA 595 64 Dubai ARE 669181 65 Abu Dhabi ARE 398695 66 Sharja ARE 320095 67 al-Ayn ARE 225970 68 Ajman ARE 114395 129 Oranjestad ABW 29034 191 Hamilton BMU 1200 528 Hartlepool GBR 92000 529 Halifax GBR 91069 914 Sekondi-Takoradi GHA 103653 943 Palembang IDN 1222764 950 Padang IDN 534474 983 Palu IDN 142800 984 Pasuruan IDN 134019 991 Pangkal Pinang IDN 124000 1003 Pemalang IDN 103500 1004 Klaten IDN 103300 1007 Palangka Raya IDN 99693 1020 Padang Sidempuan IDN 91200 1045 Patna IND 917243 1114 Panihati IND 275990 1129 Patiala IND 238368 1142 Panipat IND 215218 1159 Parbhani IND 190255 1231 Pali IND 136842 1263 Pathankot IND 123930 1265 Palghat (Palakkad) IND 123289 1293 Pallavaram IND 111866 1319 Tellicherry (Thalassery) IND 103579 1339 Palayankottai IND 97662 1345 Patan IND 96109 1436 Marv Dasht IRN 103579 1468 Palermo ITA 683794 1478 Padova ITA 211391 1484 Parma ITA 168717 SELECT * FROM City USE INDEX () WHERE ((ID < 200) AND (Name LIKE 'Ha%' OR (Country > 'A' AND Country < 'ARG'))) OR ((ID BETWEEN 100 AND 200) AND (Name LIKE 'Pa%' OR (Population > 103000 AND Population < 104000))); ID Name Country Population 1 Kabul AFG 1780000 2 Qandahar AFG 237500 3 Herat AFG 186800 4 Mazar-e-Sharif AFG 127800 7 Haag NLD 440900 16 Haarlem NLD 148772 25 Haarlemmermeer NLD 110722 33 Willemstad ANT 2345 34 Tirana ALB 270000 55 Andorra la Vella AND 21189 56 Luanda AGO 2022000 57 Huambo AGO 163100 58 Lobito AGO 130000 59 Benguela AGO 128300 60 Namibe AGO 118200 61 South Hill AIA 961 62 The Valley AIA 595 64 Dubai ARE 669181 65 Abu Dhabi ARE 398695 66 Sharja ARE 320095 67 al-Ayn ARE 225970 68 Ajman ARE 114395 100 Paraná ARG 207041 129 Oranjestad ABW 29034 167 Jamalpur BGD 103556 168 Pabna BGD 103277 189 Parakou BEN 103577 191 Hamilton BMU 1200 SELECT * FROM City WHERE ((ID < 200) AND (Name LIKE 'Ha%' OR (Country > 'A' AND Country < 'ARG'))) OR ((ID BETWEEN 100 AND 200) AND (Name LIKE 'Pa%' OR (Population > 103000 AND Population < 104000))); ID Name Country Population 1 Kabul AFG 1780000 2 Qandahar AFG 237500 3 Herat AFG 186800 4 Mazar-e-Sharif AFG 127800 7 Haag NLD 440900 16 Haarlem NLD 148772 25 Haarlemmermeer NLD 110722 33 Willemstad ANT 2345 34 Tirana ALB 270000 55 Andorra la Vella AND 21189 56 Luanda AGO 2022000 57 Huambo AGO 163100 58 Lobito AGO 130000 59 Benguela AGO 128300 60 Namibe AGO 118200 61 South Hill AIA 961 62 The Valley AIA 595 64 Dubai ARE 669181 65 Abu Dhabi ARE 398695 66 Sharja ARE 320095 67 al-Ayn ARE 225970 68 Ajman ARE 114395 100 Paraná ARG 207041 129 Oranjestad ABW 29034 167 Jamalpur BGD 103556 168 Pabna BGD 103277 189 Parakou BEN 103577 191 Hamilton BMU 1200 EXPLAIN SELECT * FROM City WHERE Population > 101000 AND Population < 102000; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population Population 4 NULL 39 Using index condition EXPLAIN SELECT * FROM City WHERE Population > 101000 AND Population < 110000; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population Population 4 NULL 328 Using index condition EXPLAIN SELECT * FROM City WHERE Country < 'C'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Country Country 3 NULL 436 Using index condition EXPLAIN SELECT * FROM City WHERE Country < 'AGO'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Country Country 3 NULL 6 Using index condition EXPLAIN SELECT * FROM City WHERE Name BETWEEN 'P' AND 'S'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 221 Using index condition EXPLAIN SELECT * FROM City WHERE Name BETWEEN 'P' AND 'Pb'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 39 Using index condition EXPLAIN SELECT * FROM City WHERE ID BETWEEN 3400 AND 3800; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY PRIMARY 4 NULL 401 Using index condition EXPLAIN SELECT * FROM City WHERE ID BETWEEN 3790 AND 3800; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY PRIMARY 4 NULL 11 Using index condition EXPLAIN SELECT * FROM City WHERE Name LIKE 'P%'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 135 Using index condition EXPLAIN SELECT * FROM City WHERE ((Population > 101000 AND Population < 102000) AND (Country < 'C' OR Name BETWEEN 'P' AND 'S')) OR ((ID BETWEEN 3400 AND 3800) AND (Country < 'AGO' OR Name LIKE 'Pa%')); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge PRIMARY,Population,Country,Name Country,Name,Population 3,35,4 NULL 84 Using sort_union(Country,Name,Population); Using where EXPLAIN SELECT * FROM City WHERE ((Population > 101000 AND Population < 110000) AND (Country < 'AGO' OR Name BETWEEN 'P' AND 'Pb')) OR ((ID BETWEEN 3790 AND 3800) AND (Country < 'C' OR Name LIKE 'P%')); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge PRIMARY,Population,Country,Name Country,Name,PRIMARY 3,35,4 NULL 56 Using sort_union(Country,Name,PRIMARY); Using where SELECT * FROM City USE INDEX () WHERE ((Population > 101000 AND Population < 102000) AND (Country < 'C' OR Name BETWEEN 'P' AND 'S')) OR ((ID BETWEEN 3400 AND 3800) AND (Country < 'AGO' OR Name LIKE 'Pa%')); ID Name Country Population 169 Naogaon BGD 101266 205 Francistown BWA 101805 417 Itaituba BRA 101320 418 Araras BRA 101046 751 Potchefstroom ZAF 101817 2909 Puno PER 101578 3463 Pavlograd UKR 127000 SELECT * FROM City WHERE ((Population > 101000 AND Population < 102000) AND (Country < 'C' OR Name BETWEEN 'P' AND 'S')) OR ((ID BETWEEN 3400 AND 3800) AND (Country < 'AGO' OR Name LIKE 'Pa%')); ID Name Country Population 169 Naogaon BGD 101266 205 Francistown BWA 101805 417 Itaituba BRA 101320 418 Araras BRA 101046 751 Potchefstroom ZAF 101817 2909 Puno PER 101578 3463 Pavlograd UKR 127000 SELECT * FROM City USE INDEX () WHERE ((Population > 101000 AND Population < 110000) AND (Country < 'AGO' OR Name BETWEEN 'P' AND 'Pb')) OR ((ID BETWEEN 3790 AND 3800) AND (Country < 'C' OR Name LIKE 'P%')); ID Name Country Population 168 Pabna BGD 103277 189 Parakou BEN 103577 750 Paarl ZAF 105768 2865 Pak Pattan PAK 107800 3797 Philadelphia USA 1517550 3798 Phoenix USA 1321045 SELECT * FROM City WHERE ((Population > 101000 AND Population < 110000) AND (Country < 'AGO' OR Name BETWEEN 'P' AND 'Pb')) OR ((ID BETWEEN 3790 AND 3800) AND (Country < 'C' OR Name LIKE 'P%')); ID Name Country Population 168 Pabna BGD 103277 189 Parakou BEN 103577 750 Paarl ZAF 105768 2865 Pak Pattan PAK 107800 3797 Philadelphia USA 1517550 3798 Phoenix USA 1321045 CREATE INDEX CountryPopulation ON City(Country,Population); EXPLAIN SELECT * FROM City WHERE Name LIKE 'Pas%'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 5 Using index condition EXPLAIN SELECT * FROM City WHERE Name LIKE 'P%'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 135 Using index condition EXPLAIN SELECT * FROM City WHERE (Population > 101000 AND Population < 103000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population Population 4 NULL 81 Using index condition EXPLAIN SELECT * FROM City WHERE Country='USA'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City ref Country,CountryPopulation Country 3 const 267 Using index condition EXPLAIN SELECT * FROM City WHERE Country='FIN'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City ref Country,CountryPopulation Country 3 const 6 Using index condition EXPLAIN SELECT * FROM City WHERE ((Population > 101000 AND Population < 103000) OR Name LIKE 'Pas%') AND Country='USA'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge Population,Country,Name,CountryPopulation CountryPopulation,Name 7,35 NULL 15 Using sort_union(CountryPopulation,Name); Using where EXPLAIN SELECT * FROM City WHERE ((Population > 101000 AND Population < 103000) OR Name LIKE 'P%') AND Country='FIN'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City ref Population,Country,Name,CountryPopulation Country 3 const 6 Using index condition; Using where SELECT * FROM City WHERE ((Population > 101000 AND Population < 103000) OR Name LIKE 'Pas%') AND Country='USA'; ID Name Country Population 3943 Pasadena USA 141674 3953 Pasadena USA 133936 4023 Gary USA 102746 4024 Berkeley USA 102743 4025 Santa Clara USA 102361 4026 Green Bay USA 102313 4027 Cape Coral USA 102286 4028 Arvada USA 102153 4029 Pueblo USA 102121 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 SELECT * FROM City USE INDEX () WHERE ((Population > 101000 AND Population < 103000) OR Name LIKE 'Pas%') AND Country='USA'; ID Name Country Population 3943 Pasadena USA 141674 3953 Pasadena USA 133936 4023 Gary USA 102746 4024 Berkeley USA 102743 4025 Santa Clara USA 102361 4026 Green Bay USA 102313 4027 Cape Coral USA 102286 4028 Arvada USA 102153 4029 Pueblo USA 102121 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 SELECT * FROM City WHERE ((Population > 101000 AND Population < 103000) OR Name LIKE 'P%') AND Country='FIN'; ID Name Country Population SELECT * FROM City USE INDEX () WHERE ((Population > 101000 AND Population < 103000) OR Name LIKE 'P%') AND Country='FIN'; ID Name Country Population CREATE INDEX CountryName ON City(Country,Name); EXPLAIN SELECT * FROM City WHERE Country='USA'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City ref Country,CountryPopulation,CountryName Country 3 const 267 Using index condition EXPLAIN SELECT * FROM City WHERE Country='FIN'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City ref Country,CountryPopulation,CountryName CountryName 3 const 5 Using index condition EXPLAIN SELECT * FROM City WHERE Country='BRA'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City ref Country,CountryPopulation,CountryName CountryName 3 const 221 Using index condition EXPLAIN SELECT * FROM City WHERE ID BETWEEN 3790 AND 3800; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY PRIMARY 4 NULL 11 Using index condition EXPLAIN SELECT * FROM City WHERE ID BETWEEN 4025 AND 4035; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY PRIMARY 4 NULL 11 Using index condition EXPLAIN SELECT * FROM City WHERE ID BETWEEN 4028 AND 4032; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY PRIMARY 4 NULL 5 Using index condition EXPLAIN SELECT * FROM City WHERE ID BETWEEN 3500 AND 3800; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY PRIMARY 4 NULL 301 Using index condition EXPLAIN SELECT * FROM City WHERE ID BETWEEN 4000 AND 4300; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY PRIMARY 4 NULL 80 Using index condition EXPLAIN SELECT * FROM City WHERE ID BETWEEN 250 and 260 ; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY PRIMARY 4 NULL 11 Using index condition EXPLAIN SELECT * FROM City WHERE (Population > 101000 AND Population < 102000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population Population 4 NULL 39 Using index condition EXPLAIN SELECT * FROM City WHERE (Population > 101000 AND Population < 103000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Population Population 4 NULL 81 Using index condition EXPLAIN SELECT * FROM City WHERE Name LIKE 'Pa%'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Name Name 35 NULL 41 Using index condition set @tmp_range_vs_index_merge=@@optimizer_switch; set optimizer_switch='extended_keys=off'; EXPLAIN SELECT * FROM City WHERE ((Population > 101000 AND Population < 102000) OR ID BETWEEN 3790 AND 3800) AND Country='USA' AND (Name LIKE 'Pa%' OR ID BETWEEN 4025 AND 4035); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge PRIMARY,Population,Country,Name,CountryPopulation,CountryName CountryPopulation,PRIMARY 7,4 NULL 14 Using sort_union(CountryPopulation,PRIMARY); Using where EXPLAIN SELECT * FROM City WHERE ((Population > 101000 AND Population < 103000) OR ID BETWEEN 3790 AND 3800) AND Country='USA' AND (Name LIKE 'Pa%' OR ID BETWEEN 4028 AND 4032); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge PRIMARY,Population,Country,Name,CountryPopulation,CountryName CountryName,PRIMARY 38,4 NULL 11 Using sort_union(CountryName,PRIMARY); Using where EXPLAIN SELECT * FROM City WHERE ((Population > 101000 AND Population < 110000) OR ID BETWEEN 3500 AND 3800) AND Country='FIN' AND (Name BETWEEN 'P' AND 'T' OR ID BETWEEN 4000 AND 4300); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City ref PRIMARY,Population,Country,Name,CountryPopulation,CountryName CountryName 3 const 5 Using index condition; Using where SELECT * FROM City USE INDEX () WHERE ((Population > 101000 AND Population < 102000) OR ID BETWEEN 3790 AND 3800) AND Country='USA' AND (Name LIKE 'Pa%' OR ID BETWEEN 4025 AND 4035); ID Name Country Population 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 SELECT * FROM City WHERE ((Population > 101000 AND Population < 102000) OR ID BETWEEN 3790 AND 3800) AND Country='USA' AND (Name LIKE 'Pa%' OR ID BETWEEN 4025 AND 4035); ID Name Country Population 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 SELECT * FROM City USE INDEX () WHERE ((Population > 101000 AND Population < 102000) OR ID BETWEEN 3790 AND 3800) AND Country='USA' AND (Name LIKE 'Pa%' OR ID BETWEEN 4028 AND 4032); ID Name Country Population 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 SELECT * FROM City WHERE ((Population > 101000 AND Population < 102000) OR ID BETWEEN 3790 AND 3800) AND Country='USA' AND (Name LIKE 'Pa%' OR ID BETWEEN 4028 AND 4032); ID Name Country Population 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 SELECT * FROM City USE INDEX () WHERE ((Population > 101000 AND Population < 102000) OR ID BETWEEN 3790 AND 3800) AND Country='FIN' AND (Name LIKE 'Pa%' OR ID BETWEEN 4025 AND 4035); ID Name Country Population SELECT * FROM City WHERE ((Population > 101000 AND Population < 102000) OR ID BETWEEN 3790 AND 3800) AND Country='FIN' AND (Name LIKE 'Pa%' OR ID BETWEEN 4025 AND 4035); ID Name Country Population EXPLAIN SELECT * FROM City WHERE ((Population > 101000 and Population < 102000) OR ID BETWEEN 3790 AND 3800) AND Country='USA' OR (Name LIKE 'Pa%' OR ID BETWEEN 250 AND 260) AND Country='BRA'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge PRIMARY,Population,Country,Name,CountryPopulation,CountryName CountryPopulation,PRIMARY,CountryName 7,4,38 NULL 35 Using sort_union(CountryPopulation,PRIMARY,CountryName); Using where SELECT * FROM City USE INDEX () WHERE ((Population > 101000 and Population < 102000) OR ID BETWEEN 3790 AND 3800) AND Country='USA' OR (Name LIKE 'Pa%' OR ID BETWEEN 250 AND 260) AND Country='BRA'; ID Name Country Population 250 Mauá BRA 375055 251 Carapicuíba BRA 357552 252 Olinda BRA 354732 253 Campina Grande BRA 352497 254 São José do Rio Preto BRA 351944 255 Caxias do Sul BRA 349581 256 Moji das Cruzes BRA 339194 257 Diadema BRA 335078 258 Aparecida de Goiânia BRA 324662 259 Piracicaba BRA 319104 260 Cariacica BRA 319033 285 Paulista BRA 248473 339 Passo Fundo BRA 166343 364 Parnaíba BRA 129756 372 Paranaguá BRA 126076 379 Palmas BRA 121919 386 Patos de Minas BRA 119262 424 Passos BRA 98570 430 Paulo Afonso BRA 97291 435 Parnamirim BRA 96210 448 Patos BRA 90519 451 Palhoça BRA 89465 3793 New York USA 8008278 3794 Los Angeles USA 3694820 3795 Chicago USA 2896016 3796 Houston USA 1953631 3797 Philadelphia USA 1517550 3798 Phoenix USA 1321045 3799 San Diego USA 1223400 3800 Dallas USA 1188580 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 SELECT * FROM City WHERE ((Population > 101000 and Population < 102000) OR ID BETWEEN 3790 AND 3800) AND Country='USA' OR (Name LIKE 'Pa%' OR ID BETWEEN 250 AND 260) AND Country='BRA'; ID Name Country Population 250 Mauá BRA 375055 251 Carapicuíba BRA 357552 252 Olinda BRA 354732 253 Campina Grande BRA 352497 254 São José do Rio Preto BRA 351944 255 Caxias do Sul BRA 349581 256 Moji das Cruzes BRA 339194 257 Diadema BRA 335078 258 Aparecida de Goiânia BRA 324662 259 Piracicaba BRA 319104 260 Cariacica BRA 319033 285 Paulista BRA 248473 339 Passo Fundo BRA 166343 364 Parnaíba BRA 129756 372 Paranaguá BRA 126076 379 Palmas BRA 121919 386 Patos de Minas BRA 119262 424 Passos BRA 98570 430 Paulo Afonso BRA 97291 435 Parnamirim BRA 96210 448 Patos BRA 90519 451 Palhoça BRA 89465 3793 New York USA 8008278 3794 Los Angeles USA 3694820 3795 Chicago USA 2896016 3796 Houston USA 1953631 3797 Philadelphia USA 1517550 3798 Phoenix USA 1321045 3799 San Diego USA 1223400 3800 Dallas USA 1188580 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 EXPLAIN SELECT * FROM City WHERE ((Population > 101000 AND Population < 11000) OR ID BETWEEN 3500 AND 3800) AND Country='USA' AND (Name LIKE 'P%' OR ID BETWEEN 4000 AND 4300); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY,Population,Country,Name,CountryPopulation,CountryName CountryName 38 NULL 23 Using index condition; Using where EXPLAIN SELECT * FROM City WHERE ((Population > 101000 AND Population < 11000) OR ID BETWEEN 3500 AND 3800) AND Country='USA' AND (Name LIKE 'Pho%' OR ID BETWEEN 4000 AND 4300); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range PRIMARY,Population,Country,Name,CountryPopulation,CountryName Name 35 NULL 1 Using where SELECT * FROM City USE INDEX () WHERE ((Population > 101000 AND Population < 11000) OR ID BETWEEN 3500 AND 3800) AND Country='USA' AND (Name LIKE 'P%' OR ID BETWEEN 4000 AND 4300); ID Name Country Population 3797 Philadelphia USA 1517550 3798 Phoenix USA 1321045 SELECT * FROM City WHERE ((Population > 101000 AND Population < 11000) OR ID BETWEEN 3500 AND 3800) AND Country='USA' AND (Name LIKE 'P%' OR ID BETWEEN 4000 AND 4300); ID Name Country Population 3797 Philadelphia USA 1517550 3798 Phoenix USA 1321045 SELECT * FROM City USE INDEX () WHERE ((Population > 101000 AND Population < 11000) OR ID BETWEEN 3500 AND 3800) AND Country='USA' AND (Name LIKE 'Pho%' OR ID BETWEEN 4000 AND 4300); ID Name Country Population 3798 Phoenix USA 1321045 SELECT * FROM City WHERE ((Population > 101000 AND Population < 11000) OR ID BETWEEN 3500 AND 3800) AND Country='USA' AND (Name LIKE 'Pho%' OR ID BETWEEN 4000 AND 4300); ID Name Country Population 3798 Phoenix USA 1321045 DROP INDEX Population ON City; DROP INDEX Name ON City; set optimizer_switch=@tmp_range_vs_index_merge; EXPLAIN SELECT * FROM City WHERE Country='USA' AND Population BETWEEN 101000 AND 102000 OR Country='USA' AND Name LIKE 'Pa%'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge Country,CountryPopulation,CountryName CountryPopulation,CountryName 7,38 NULL 10 Using sort_union(CountryPopulation,CountryName); Using where SELECT * FROM City USE INDEX() WHERE Country='USA' AND Population BETWEEN 101000 AND 102000 OR Country='USA' AND Name LIKE 'Pa%'; ID Name Country Population 3932 Paterson USA 149222 3943 Pasadena USA 141674 3953 Pasadena USA 133936 3967 Paradise USA 124682 3986 Palmdale USA 116670 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 SELECT * FROM City WHERE Country='USA' AND Population BETWEEN 101000 AND 102000 OR Country='USA' AND Name LIKE 'Pa%'; ID Name Country Population 3932 Paterson USA 149222 3943 Pasadena USA 141674 3953 Pasadena USA 133936 3967 Paradise USA 124682 3986 Palmdale USA 116670 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 EXPLAIN SELECT * FROM City WHERE Country='USA' AND (Population BETWEEN 101000 AND 102000 OR Name LIKE 'Pa%'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge Country,CountryPopulation,CountryName CountryPopulation,CountryName 7,38 NULL 10 Using sort_union(CountryPopulation,CountryName); Using where SELECT * FROM City WHERE Country='USA' AND (Population BETWEEN 101000 AND 102000 OR Name LIKE 'Pa%'); ID Name Country Population 3932 Paterson USA 149222 3943 Pasadena USA 141674 3953 Pasadena USA 133936 3967 Paradise USA 124682 3986 Palmdale USA 116670 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 SELECT * FROM City WHERE Country='USA' AND (Population BETWEEN 101000 AND 102000 OR Name LIKE 'Pa%'); ID Name Country Population 3932 Paterson USA 149222 3943 Pasadena USA 141674 3953 Pasadena USA 133936 3967 Paradise USA 124682 3986 Palmdale USA 116670 4030 Sandy USA 101853 4031 Athens-Clarke County USA 101489 4032 Cambridge USA 101355 set @save_optimizer_switch=@@optimizer_switch; CREATE INDEX CityName on City(Name); EXPLAIN SELECT Name, Country, Population FROM City WHERE (Name='Manila' AND Country='PHL') OR (Name='Addis Abeba' AND Country='ETH') OR (Name='Jakarta' AND Country='IDN') OR (Name='Bangalore' AND Country='IND') OR (Name='Teheran' AND Country='IRN') OR (Name='Roma' AND Country='ITA') OR (Name='Delhi' AND Country='IND') OR (Name='Venezia' AND Country='ITA') OR (Name='Tokyo' AND Country='JPN') OR (Name='Toronto' AND Country='CAN') OR (Name='Peking' AND Country='CHN') OR (Name='Lagos' AND Country='NGA') OR (Name='Tijuana' AND Country='MEX') OR (Name='Rabat' AND Country='MAR') OR (Name='Seoul' AND Country='KOR') OR (Name='Vancouver' AND Country='CAN') OR (Name='Kaunas' AND Country='LTU') OR (Name='Paris' AND Country='FRA') OR (Name='Dakar' AND Country='SEN') OR (Name='Basel' AND Country='CHE') OR (Name='Praha' AND Country='CZE') OR (Name='Ankara' AND Country='TUR') OR (Name='Dresden' AND Country='DEU') OR (Name='Lugansk' AND Country='UKR') OR (Name='Caracas' AND Country='VEN') OR (Name='Samara' AND Country='RUS') OR (Name='Seattle' AND Country='USA'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge Country,CountryPopulation,CountryName,CityName CountryName,CityName 38,35 NULL 28 Using sort_union(CountryName,CityName); Using where SELECT Name, Country, Population FROM City WHERE (Name='Manila' AND Country='PHL') OR (Name='Addis Abeba' AND Country='ETH') OR (Name='Jakarta' AND Country='IDN') OR (Name='Bangalore' AND Country='IND') OR (Name='Teheran' AND Country='IRN') OR (Name='Roma' AND Country='ITA') OR (Name='Delhi' AND Country='IND') OR (Name='Venezia' AND Country='ITA') OR (Name='Tokyo' AND Country='JPN') OR (Name='Toronto' AND Country='CAN') OR (Name='Peking' AND Country='CHN') OR (Name='Lagos' AND Country='NGA') OR (Name='Tijuana' AND Country='MEX') OR (Name='Rabat' AND Country='MAR') OR (Name='Seoul' AND Country='KOR') OR (Name='Vancouver' AND Country='CAN') OR (Name='Kaunas' AND Country='LTU') OR (Name='Paris' AND Country='FRA') OR (Name='Dakar' AND Country='SEN') OR (Name='Basel' AND Country='CHE') OR (Name='Praha' AND Country='CZE') OR (Name='Ankara' AND Country='TUR') OR (Name='Dresden' AND Country='DEU') OR (Name='Lugansk' AND Country='UKR') OR (Name='Caracas' AND Country='VEN') OR (Name='Samara' AND Country='RUS') OR (Name='Seattle' AND Country='USA'); Name Country Population Addis Abeba ETH 2495000 Manila PHL 1581082 Jakarta IDN 9604900 Delhi IND 7206704 Bangalore IND 2660088 Teheran IRN 6758845 Roma ITA 2643581 Venezia ITA 277305 Tokyo JPN 7980230 Toronto CAN 688275 Vancouver CAN 514008 Peking CHN 7472000 Seoul KOR 9981619 Kaunas LTU 412639 Rabat MAR 623457 Tijuana MEX 1212232 Lagos NGA 1518000 Paris FRA 2125246 Dresden DEU 476668 Dakar SEN 785071 Basel CHE 166700 Praha CZE 1181126 Ankara TUR 3038159 Lugansk UKR 469000 Caracas VEN 1975294 Samara RUS 1156100 Seattle USA 563374 set optimizer_switch='index_merge=off'; EXPLAIN SELECT Name, Country, Population FROM City WHERE (Name='Manila' AND Country='PHL') OR (Name='Addis Abeba' AND Country='ETH') OR (Name='Jakarta' AND Country='IDN') OR (Name='Bangalore' AND Country='IND') OR (Name='Teheran' AND Country='IRN') OR (Name='Roma' AND Country='ITA') OR (Name='Delhi' AND Country='IND') OR (Name='Venezia' AND Country='ITA') OR (Name='Tokyo' AND Country='JPN') OR (Name='Toronto' AND Country='CAN') OR (Name='Peking' AND Country='CHN') OR (Name='Lagos' AND Country='NGA') OR (Name='Tijuana' AND Country='MEX') OR (Name='Rabat' AND Country='MAR') OR (Name='Seoul' AND Country='KOR') OR (Name='Vancouver' AND Country='CAN') OR (Name='Kaunas' AND Country='LTU') OR (Name='Paris' AND Country='FRA') OR (Name='Dakar' AND Country='SEN') OR (Name='Basel' AND Country='CHE') OR (Name='Praha' AND Country='CZE') OR (Name='Ankara' AND Country='TUR') OR (Name='Dresden' AND Country='DEU') OR (Name='Lugansk' AND Country='UKR') OR (Name='Caracas' AND Country='VEN') OR (Name='Samara' AND Country='RUS') OR (Name='Seattle' AND Country='USA'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Country,CountryPopulation,CountryName,CityName CountryName 38 NULL 29 Using index condition; Using where SELECT Name, Country, Population FROM City WHERE (Name='Manila' AND Country='PHL') OR (Name='Addis Abeba' AND Country='ETH') OR (Name='Jakarta' AND Country='IDN') OR (Name='Bangalore' AND Country='IND') OR (Name='Teheran' AND Country='IRN') OR (Name='Roma' AND Country='ITA') OR (Name='Delhi' AND Country='IND') OR (Name='Venezia' AND Country='ITA') OR (Name='Tokyo' AND Country='JPN') OR (Name='Toronto' AND Country='CAN') OR (Name='Peking' AND Country='CHN') OR (Name='Lagos' AND Country='NGA') OR (Name='Tijuana' AND Country='MEX') OR (Name='Rabat' AND Country='MAR') OR (Name='Seoul' AND Country='KOR') OR (Name='Vancouver' AND Country='CAN') OR (Name='Kaunas' AND Country='LTU') OR (Name='Paris' AND Country='FRA') OR (Name='Dakar' AND Country='SEN') OR (Name='Basel' AND Country='CHE') OR (Name='Praha' AND Country='CZE') OR (Name='Ankara' AND Country='TUR') OR (Name='Dresden' AND Country='DEU') OR (Name='Lugansk' AND Country='UKR') OR (Name='Caracas' AND Country='VEN') OR (Name='Samara' AND Country='RUS') OR (Name='Seattle' AND Country='USA'); Name Country Population Toronto CAN 688275 Vancouver CAN 514008 Basel CHE 166700 Peking CHN 7472000 Praha CZE 1181126 Dresden DEU 476668 Addis Abeba ETH 2495000 Paris FRA 2125246 Jakarta IDN 9604900 Bangalore IND 2660088 Delhi IND 7206704 Teheran IRN 6758845 Roma ITA 2643581 Venezia ITA 277305 Tokyo JPN 7980230 Seoul KOR 9981619 Kaunas LTU 412639 Rabat MAR 623457 Tijuana MEX 1212232 Lagos NGA 1518000 Manila PHL 1581082 Samara RUS 1156100 Dakar SEN 785071 Ankara TUR 3038159 Lugansk UKR 469000 Seattle USA 563374 Caracas VEN 1975294 set optimizer_switch=@save_optimizer_switch; # # Bug mdev-585: range vs index-merge with ORDER BY ... LIMIT n # (LP bug #637962) # DROP INDEX CountryPopulation ON City; DROP INDEX CountryName ON City; DROP INDEX CityName on City; CREATE INDEX Name ON City(Name); CREATE INDEX Population ON City(Population); EXPLAIN SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'H')) AND (Population >= 100000 AND Population < 120000); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City index_merge Country,Name,Population Name,Country 35,3 NULL # Using sort_union(Name,Country); Using where FLUSH STATUS; SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'H')) AND (Population >= 100000 AND Population < 120000); ID Name Country Population 384 Cabo Frio BRA 119503 387 Camaragibe BRA 118968 403 Catanduva BRA 107761 412 Cachoeirinha BRA 103240 508 Watford GBR 113080 509 Ipswich GBR 114000 510 Slough GBR 112000 511 Exeter GBR 111000 512 Cheltenham GBR 106000 513 Gloucester GBR 107000 514 Saint Helens GBR 106293 515 Sutton Coldfield GBR 106001 516 York GBR 104425 517 Oldham GBR 103931 518 Basildon GBR 100924 519 Worthing GBR 100000 635 Mallawi EGY 119283 636 Bilbays EGY 113608 637 Mit Ghamr EGY 101801 638 al-Arish EGY 100447 701 Tarragona ESP 113016 702 Lleida (Lérida) ESP 112207 703 Jaén ESP 109247 704 Ourense (Orense) ESP 109120 705 Mataró ESP 104095 706 Algeciras ESP 103106 707 Marbella ESP 101144 759 Gonder ETH 112249 869 Cabuyao PHL 106630 870 Calapan PHL 105910 873 Cauayan PHL 103952 903 Serekunda GMB 102600 909 Sohumi GEO 111700 913 Tema GHA 109975 914 Sekondi-Takoradi GHA 103653 924 Villa Nueva GTM 101295 1844 Cape Breton CAN 114733 1847 Cambridge CAN 109186 2406 Herakleion GRC 116178 2407 Kallithea GRC 114233 2408 Larisa GRC 113090 2908 Cajamarca PER 108009 3002 Besançon FRA 117733 3003 Caen FRA 113987 3004 Orléans FRA 113126 3005 Mulhouse FRA 110359 3006 Rouen FRA 106592 3007 Boulogne-Billancourt FRA 106367 3008 Perpignan FRA 105115 3009 Nancy FRA 103605 3411 Ceyhan TUR 102412 3567 Carúpano VEN 119639 3568 Catia La Mar VEN 117012 3571 Calabozo VEN 107146 3786 Cam Ranh VNM 114041 3792 Tartu EST 101246 4002 Carrollton USA 109576 4027 Cape Coral USA 102286 4032 Cambridge USA 101355 SHOW STATUS LIKE 'Handler_read_%'; Variable_name Value Handler_read_first 0 Handler_read_key 2 Handler_read_last 0 Handler_read_next 385 Handler_read_prev 0 Handler_read_retry 0 Handler_read_rnd 377 Handler_read_rnd_deleted 0 Handler_read_rnd_next 0 EXPLAIN SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'H')) AND (Population >= 100000 AND Population < 120000) ORDER BY Population LIMIT 5; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Country,Name,Population Population 4 NULL # Using where FLUSH STATUS; SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'H')) AND (Population >= 100000 AND Population < 120000) ORDER BY Population LIMIT 5; ID Name Country Population 519 Worthing GBR 100000 638 al-Arish EGY 100447 518 Basildon GBR 100924 707 Marbella ESP 101144 3792 Tartu EST 101246 SHOW STATUS LIKE 'Handler_read_%'; Variable_name Value Handler_read_first 0 Handler_read_key 1 Handler_read_last 0 Handler_read_next 59 Handler_read_prev 0 Handler_read_retry 0 Handler_read_rnd 0 Handler_read_rnd_deleted 0 Handler_read_rnd_next 0 set optimizer_switch='index_merge=off'; EXPLAIN SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'H')) AND (Population >= 100000 AND Population < 120000) ORDER BY Population LIMIT 5; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range Country,Name,Population Population 4 NULL # Using index condition; Using where FLUSH STATUS; SELECT * FROM City WHERE ((Name > 'Ca' AND Name < 'Cf') OR (Country > 'E' AND Country < 'H')) AND (Population >= 100000 AND Population < 120000) ORDER BY Population LIMIT 5; ID Name Country Population 519 Worthing GBR 100000 638 al-Arish EGY 100447 518 Basildon GBR 100924 707 Marbella ESP 101144 3792 Tartu EST 101246 SHOW STATUS LIKE 'Handler_read_%'; Variable_name Value Handler_read_first 0 Handler_read_key 1 Handler_read_last 0 Handler_read_next 59 Handler_read_prev 0 Handler_read_retry 0 Handler_read_rnd 0 Handler_read_rnd_deleted 0 Handler_read_rnd_next 0 set optimizer_switch=@save_optimizer_switch; DROP DATABASE world; use test; CREATE TABLE t1 ( id int(10) unsigned NOT NULL auto_increment, account_id int(10) unsigned NOT NULL, first_name varchar(50) default NULL, middle_name varchar(50) default NULL, last_name varchar(100) default NULL, home_address_1 varchar(150) default NULL, home_city varchar(75) default NULL, home_state char(2) default NULL, home_postal_code varchar(50) default NULL, home_county varchar(75) default NULL, home_country char(3) default NULL, work_address_1 varchar(150) default NULL, work_city varchar(75) default NULL, work_state char(2) default NULL, work_postal_code varchar(50) default NULL, work_county varchar(75) default NULL, work_country char(3) default NULL, login varchar(50) NOT NULL, PRIMARY KEY (id), KEY login (login,account_id), KEY account_id (account_id), KEY user_home_country_indx (home_country), KEY user_work_country_indx (work_country), KEY user_home_state_indx (home_state), KEY user_work_state_indx (work_state), KEY user_home_city_indx (home_city), KEY user_work_city_indx (work_city), KEY user_first_name_indx (first_name), KEY user_last_name_indx (last_name) ); insert into t1(account_id, login, home_state, work_state) values (1, 'pw', 'ia', 'ia'), (1, 'pw', 'ia', 'ia'), (1, 'pw', 'ia', 'ia'), (1, 'pw', 'ia', 'ia'), (1, 'pw', 'ia', 'ia'), (1, 'pw', 'ia', 'ia'); insert into t1(account_id, login, home_state, work_state) select 1, 'pw', 'ak', 'ak' from t1; insert into t1(account_id, login, home_state, work_state) select 1, 'pw', 'ak', 'ak' from t1; insert into t1(account_id, login, home_state, work_state) select 1, 'pw', 'ak', 'ak' from t1; insert into t1(account_id, login, home_state, work_state) select 1, 'pw', 'ak', 'ak' from t1; insert into t1(account_id, login, home_state, work_state) select 1, 'pw', 'ak', 'ak' from t1; insert into t1(account_id, login, home_state, work_state) select 1, 'pw', 'ak', 'ak' from t1; insert into t1(account_id, login, home_state, work_state) select 1, 'pw', 'ak', 'ak' from t1; insert into t1(account_id, login, home_state, work_state) select 1, 'pw', 'ak', 'ak' from t1; insert into t1(account_id, login, home_state, work_state) select 1, 'pw', 'ak', 'ak' from t1; analyze table t1; Table Op Msg_type Msg_text test.t1 analyze status OK select count(*) from t1 where account_id = 1; count(*) 3072 select * from t1 where (home_state = 'ia' or work_state='ia') and account_id = 1; id account_id first_name middle_name last_name home_address_1 home_city home_state home_postal_code home_county home_country work_address_1 work_city work_state work_postal_code work_county work_country login 1 1 NULL NULL NULL NULL NULL ia NULL NULL NULL NULL NULL ia NULL NULL NULL pw 2 1 NULL NULL NULL NULL NULL ia NULL NULL NULL NULL NULL ia NULL NULL NULL pw 3 1 NULL NULL NULL NULL NULL ia NULL NULL NULL NULL NULL ia NULL NULL NULL pw 4 1 NULL NULL NULL NULL NULL ia NULL NULL NULL NULL NULL ia NULL NULL NULL pw 5 1 NULL NULL NULL NULL NULL ia NULL NULL NULL NULL NULL ia NULL NULL NULL pw 6 1 NULL NULL NULL NULL NULL ia NULL NULL NULL NULL NULL ia NULL NULL NULL pw explain select * from t1 where (home_state = 'ia' or work_state='ia') and account_id = 1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge account_id,user_home_state_indx,user_work_state_indx user_home_state_indx,user_work_state_indx 3,3 NULL 6 Using union(user_home_state_indx,user_work_state_indx); Using where drop table t1; CREATE TABLE t1 ( c1 int(11) NOT NULL auto_increment, c2 decimal(10,0) default NULL, c3 decimal(10,0) default NULL, c4 decimal(10,0) default NULL, c5 decimal(10,0) default NULL, cp decimal(1,0) default NULL, ce decimal(10,0) default NULL, cdata char(20), PRIMARY KEY (c1), KEY k1 (c2,c3,cp,ce), KEY k2 (c4,c5,cp,ce) ); insert into t1 (c2, c3, c4, c5, cp) values(1,1,1,1,1); insert into t1 (c2, c3, c4, c5, cp) values(2,1,1,1,4); insert into t1 (c2, c3, c4, c5, cp) values(2,1,2,1,1); insert into t1 (c2, c3, c4, c5, cp) values(2,1,3,1,4); insert into t1 (c2, c3, c4, c5, cp) values(3,1,4,1,4); insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; insert into t1 (c2, c3, c4, c5, cp) select c2, c3, c4, c5, cp from t1 where cp = 4; analyze table t1; Table Op Msg_type Msg_text test.t1 analyze status OK explain select * from t1 where (c2=1 and c3=1) or (c4=2 and c5=1); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge k1,k2 k1,k2 12,12 NULL 2 Using sort_union(k1,k2); Using where explain select * from t1 where (c2=1 and c3=1 and cp=1) or (c4=2 and c5=1 and cp=1); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge k1,k2 k1,k2 14,14 NULL 2 Using sort_union(k1,k2); Using where explain select * from t1 where ((c2=1 and c3=1) or (c4=2 and c5=1)) and cp=1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge k1,k2 k1,k2 14,14 NULL 2 Using sort_union(k1,k2); Using where select * from t1 where (c2=1 and c3=1 and cp=1) or (c4=2 and c5=1 and cp=1); c1 c2 c3 c4 c5 cp ce cdata 1 1 1 1 1 1 NULL NULL 3 2 1 2 1 1 NULL NULL select * from t1 where ((c2=1 and c3=1) or (c4=2 and c5=1)) and cp=1; c1 c2 c3 c4 c5 cp ce cdata 1 1 1 1 1 1 NULL NULL 3 2 1 2 1 1 NULL NULL drop table t1; create table t1 ( c1 int auto_increment primary key, c2 char(20), c3 char (20), c4 int ); alter table t1 add key k1 (c2); alter table t1 add key k2 (c3); alter table t1 add key k3 (c4); insert into t1 values(null, 'a', 'b', 0); insert into t1 values(null, 'c', 'b', 0); insert into t1 values(null, 'a', 'd', 0); insert into t1 values(null, 'ccc', 'qqq', 0); insert into t1 (c2,c3) select c2,c3 from t1 where c2 != 'a'; insert into t1 (c2,c3) select c2,c3 from t1 where c2 != 'a'; insert into t1 (c2,c3) select c2,c3 from t1 where c2 != 'a'; insert into t1 (c2,c3) select c2,c3 from t1 where c2 != 'a'; insert into t1 (c2,c3) select c2,c3 from t1 where c2 != 'a'; insert into t1 (c2,c3) select c2,c3 from t1 where c2 != 'a'; insert into t1 (c2,c3) select c2,c3 from t1 where c2 != 'a'; insert into t1 (c2,c3,c4) select c2,c3,1 from t1 where c2 != 'a'; insert into t1 (c2,c3,c4) select c2,c3,2 from t1 where c2 != 'a'; insert into t1 (c2,c3,c4) select c2,c3,3 from t1 where c2 != 'a'; insert into t1 (c2,c3,c4) select c2,c3,4 from t1 where c2 != 'a'; analyze table t1; Table Op Msg_type Msg_text test.t1 analyze status OK select count(*) from t1 where (c2='e' OR c3='q'); count(*) 0 select count(*) from t1 where c4 != 0; count(*) 3840 explain select distinct c1 from t1 where (c2='e' OR c3='q'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge k1,k2 k1,k2 21,21 NULL 2 Using union(k1,k2); Using where explain select distinct c1 from t1 where (c4!= 0) AND (c2='e' OR c3='q'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge k1,k2,k3 k1,k2 21,21 NULL 2 Using union(k1,k2); Using where drop table t1; create table t1 ( id int unsigned auto_increment primary key, c1 char(12), c2 char(15), c3 char(1) ); insert into t1 (c3) values ('1'), ('2'); insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; insert into t1 (c3) select c3 from t1; update t1 set c1=lpad(id+1000, 12, ' '), c2=lpad(id+10000, 15, ' '); alter table t1 add unique index (c1), add unique index (c2), add index (c3); analyze table t1; Table Op Msg_type Msg_text test.t1 analyze status Table is already up to date explain select * from t1 where (c1=' 100000' or c2=' 2000000'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge c1,c2 c1,c2 13,16 NULL 2 Using union(c1,c2); Using where explain select * from t1 where (c1=' 100000' or c2=' 2000000') and c3='2'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge c1,c2,c3 c1,c2 13,16 NULL 2 Using union(c1,c2); Using where select * from t1 where (c1=' 100000' or c2=' 2000000'); id c1 c2 c3 select * from t1 where (c1=' 100000' or c2=' 2000000') and c3='2'; id c1 c2 c3 drop table t1; CREATE TABLE t1 ( a smallint DEFAULT NULL, pk int NOT NULL AUTO_INCREMENT PRIMARY KEY, b varchar(10) DEFAULT NULL, c varchar(64) DEFAULT NULL, INDEX idx1 (a), INDEX idx2 (b), INDEX idx3 (c) ); SELECT COUNT(*) FROM t1 IGNORE INDEX (idx2,idx3) WHERE c = 'i' OR b IN ( 'Arkansas' , 'd' , 'pdib' , 'can' ) OR (pk BETWEEN 120 AND 79 + 255 OR a IN ( 4 , 179 , 1 ) ) AND a > 8 ; COUNT(*) 5 SELECT COUNT(*) FROM t1 WHERE c = 'i' OR b IN ( 'Arkansas' , 'd' , 'pdib' , 'can' ) OR (pk BETWEEN 120 AND 79 + 255 OR a IN ( 4 , 179 , 1 ) ) AND a > 8 ; COUNT(*) 5 EXPLAIN SELECT COUNT(*) FROM t1 WHERE c = 'i' OR b IN ( 'Arkansas' , 'd' , 'pdib' , 'can' ) OR (pk BETWEEN 120 AND 79 + 255 OR a IN ( 4 , 179 , 1 ) ) AND a > 8 ; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge PRIMARY,idx1,idx2,idx3 idx3,idx2,PRIMARY,idx1 67,13,4,3 NULL 8 Using sort_union(idx3,idx2,PRIMARY,idx1); Using where DROP TABLE t1; CREATE TABLE t1 ( f1 int, f2 int, f3 int, f4 int, f5 int, PRIMARY KEY (f4), KEY (f1), KEY (f2), KEY (f3) ) ; INSERT INTO t1 VALUES (0,0,NULL,9,5), (0,0,1,9425,NULL); SELECT f5 FROM t1 WHERE f2 != 1 OR f1 IS NULL OR f4 = 4 OR f2 AND (f4 BETWEEN 6 AND 255 OR f3 IS NULL); f5 5 NULL DROP TABLE t1; CREATE TABLE t1 ( f1 int, f2 int, f3 int, f4 int, PRIMARY KEY (f1), KEY (f3), KEY (f4) ); INSERT INTO t1 VALUES (9,0,2,6), (9930,0,0,NULL); SET SESSION optimizer_switch='index_merge_intersection=off'; SET SESSION optimizer_switch='index_merge_sort_union=off'; SET SESSION optimizer_switch='index_merge_union=off'; EXPLAIN SELECT * FROM t1 FORCE KEY (PRIMARY,f3,f4) WHERE ( f3 = 1 OR f1 = 7 ) AND f1 < 10 OR f3 BETWEEN 2 AND 2 AND ( f3 = 1 OR f4 != 1 ); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL PRIMARY,f3,f4 NULL NULL NULL 2 Using where SELECT * FROM t1 FORCE KEY (PRIMARY,f3,f4) WHERE ( f3 = 1 OR f1 = 7 ) AND f1 < 10 OR f3 BETWEEN 2 AND 2 AND ( f3 = 1 OR f4 != 1 ); f1 f2 f3 f4 9 0 2 6 SET SESSION optimizer_switch='index_merge_union=on'; EXPLAIN SELECT * FROM t1 FORCE KEY (PRIMARY,f3,f4) WHERE ( f3 = 1 OR f1 = 7 ) AND f1 < 10 OR f3 BETWEEN 2 AND 2 AND ( f3 = 1 OR f4 != 1 ); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL PRIMARY,f3,f4 NULL NULL NULL 2 Using where SELECT * FROM t1 FORCE KEY (PRIMARY,f3,f4) WHERE ( f3 = 1 OR f1 = 7 ) AND f1 < 10 OR f3 BETWEEN 2 AND 2 AND ( f3 = 1 OR f4 != 1 ); f1 f2 f3 f4 9 0 2 6 INSERT INTO t1 VALUES (93,0,3,6), (9933,0,3,3), (94,0,4,6), (9934,0,4,4), (95,0,5,6), (9935,0,5,5), (96,0,6,6), (9936,0,6,6), (97,0,7,6), (9937,0,7,7), (98,0,8,6), (9938,0,8,8), (99,0,9,6), (9939,0,9,9); SET SESSION optimizer_switch='index_merge_union=off'; EXPLAIN SELECT * FROM t1 FORCE KEY (PRIMARY,f3,f4) WHERE ( f3 = 1 OR f1 = 7 ) AND f1 < 10 OR f3 BETWEEN 2 AND 2 AND ( f3 = 1 OR f4 != 1 ); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL PRIMARY,f3,f4 NULL NULL NULL 16 Using where SELECT * FROM t1 FORCE KEY (PRIMARY,f3,f4) WHERE ( f3 = 1 OR f1 = 7 ) AND f1 < 10 OR f3 BETWEEN 2 AND 2 AND ( f3 = 1 OR f4 != 1 ); f1 f2 f3 f4 9 0 2 6 SET SESSION optimizer_switch='index_merge_union=on'; EXPLAIN SELECT * FROM t1 FORCE KEY (PRIMARY,f3,f4) WHERE ( f3 = 1 OR f1 = 7 ) AND f1 < 10 OR f3 BETWEEN 2 AND 2 AND ( f3 = 1 OR f4 != 1 ); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge PRIMARY,f3,f4 f3,PRIMARY,f3 5,4,5 NULL 3 Using union(f3,PRIMARY,f3); Using where SELECT * FROM t1 FORCE KEY (PRIMARY,f3,f4) WHERE ( f3 = 1 OR f1 = 7 ) AND f1 < 10 OR f3 BETWEEN 2 AND 2 AND ( f3 = 1 OR f4 != 1 ); f1 f2 f3 f4 9 0 2 6 SET SESSION optimizer_switch=DEFAULT; DROP TABLE t1; CREATE TABLE t1 (f1 int) ; INSERT INTO t1 VALUES (0), (0); CREATE TABLE t2 (f1 int, f2 int, f3 int, f4 int, INDEX idx (f3,f2)) ; INSERT INTO t2 VALUES (5,6,0,0), (0,4,0,0); CREATE TABLE t3 (f1 int, f2 int, INDEX idx1 (f2,f1) , INDEX idx2 (f1)) ; INSERT INTO t3 VALUES (6,0),( 4,0); SELECT * FROM t1,t2,t3 WHERE (t2.f3 = 1 OR t3.f1=t2.f1) AND t3.f1 <> t2.f2 AND t3.f2 = t2.f4; f1 f1 f2 f3 f4 f1 f2 DROP TABLE t1,t2,t3; CREATE TABLE t1 ( a int, b int, c int, d int, PRIMARY KEY(b), INDEX idx1(d), INDEX idx2(d,b,c) ); INSERT INTO t1 VALUES (0,58,7,7),(0,63,2,0),(0,64,186,8),(0,65,1,-2), (0,71,190,-3), (0,72,321,-7),(0,73,0,3),(0,74,5,25),(0,75,5,3); SET SESSION optimizer_switch='index_merge_sort_union=off'; EXPLAIN SELECT * FROM t1 WHERE t1.b>7 AND t1.d>1 AND t1.d<>8 OR t1.d>=7 AND t1.d<8 OR t1.d>7; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL PRIMARY,idx1,idx2 NULL NULL NULL 9 Using where SELECT * FROM t1 WHERE t1.b>7 AND t1.d>1 AND t1.d<>8 OR t1.d>=7 AND t1.d<8 OR t1.d>7; a b c d 0 58 7 7 0 64 186 8 0 73 0 3 0 74 5 25 0 75 5 3 SET SESSION optimizer_switch='index_merge_sort_union=on'; EXPLAIN SELECT * FROM t1 WHERE t1.b>7 AND t1.d>1 AND t1.d<>8 OR t1.d>=7 AND t1.d<8 OR t1.d>7; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL PRIMARY,idx1,idx2 NULL NULL NULL 9 Using where SELECT * FROM t1 WHERE t1.b>7 AND t1.d>1 AND t1.d<>8 OR t1.d>=7 AND t1.d<8 OR t1.d>7; a b c d 0 58 7 7 0 64 186 8 0 73 0 3 0 74 5 25 0 75 5 3 SET SESSION optimizer_switch=DEFAULT; DROP TABLE t1; CREATE TABLE t1 (a int NOT NULL PRIMARY KEY, b int, c int, INDEX idx(c,b)); INSERT INTO t1 VALUES (19,1,NULL), (20,5,7); EXPLAIN SELECT * FROM t1 WHERE t1.a>300 AND t1.c!=0 AND t1.b>=350 AND t1.b<=400 AND (t1.c=0 OR t1.a=500); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY,idx PRIMARY 4 NULL 1 Using index condition; Using where SELECT * FROM t1 WHERE t1.a>300 AND t1.c!=0 AND t1.b>=350 AND t1.b<=400 AND (t1.c=0 OR t1.a=500); a b c DROP TABLE t1; CREATE TABLE t1 (a int PRIMARY KEY, b int, INDEX idx(b)); INSERT INTO t1 VALUES (167,9999), (168,10000); EXPLAIN SELECT * FROM t1 WHERE a BETWEEN 4 AND 5 AND b IN (255,4) OR a IN (2,14,25) OR a!=2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL PRIMARY,idx NULL NULL NULL 2 Using where SELECT * FROM t1 WHERE a BETWEEN 4 AND 5 AND b IN (255,4) OR a IN (2,14,25) OR a!=2; a b 167 9999 168 10000 DROP TABLE t1; # # MDEV-8603: Wrong result OR/AND condition over index fields # CREATE TABLE t1 ( id INT NOT NULL, state VARCHAR(64), capital VARCHAR(64), UNIQUE KEY (id), KEY state (state,id), KEY capital (capital, id) ); INSERT INTO t1 VALUES (1,'Arizona','Phoenix'), (2,'Hawaii','Honolulu'), (3,'Georgia','Atlanta'), (4,'Florida','Tallahassee'), (5,'Alaska','Juneau'), (6,'Michigan','Lansing'), (7,'Pennsylvania','Harrisburg'), (8,'Virginia','Richmond') ; EXPLAIN SELECT * FROM t1 FORCE KEY (state,capital) WHERE ( state = 'Alabama' OR state >= 'Colorado' ) AND id != 9 OR ( capital >= 'Topeka' OR state = 'Kansas' ) AND state != 'Texas'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range state,capital state 71 NULL 12 Using index condition; Using where SELECT * FROM t1 FORCE KEY (state,capital) WHERE ( state = 'Alabama' OR state >= 'Colorado' ) AND id != 9 OR ( capital >= 'Topeka' OR state = 'Kansas' ) AND state != 'Texas'; id state capital 4 Florida Tallahassee 3 Georgia Atlanta 2 Hawaii Honolulu 6 Michigan Lansing 7 Pennsylvania Harrisburg 8 Virginia Richmond DROP TABLE t1; # # mdev-11574: do not build index merge of two indexes when # one index is an infix of the other index # set names utf8; CREATE DATABASE world; use world; CREATE TABLE Country ( Code char(3) NOT NULL default '', Name char(52) NOT NULL default '', SurfaceArea float(10,2) NOT NULL default '0.00', Population int(11) NOT NULL default '0', Capital int(11) default NULL, PRIMARY KEY (Code), UNIQUE INDEX (Name) ); CREATE TABLE City ( ID int(11) NOT NULL auto_increment, Name char(35) NOT NULL default '', Country char(3) NOT NULL default '', Population int(11) NOT NULL default '0', PRIMARY KEY (ID), INDEX (Population), INDEX (Country) ); CREATE TABLE CountryLanguage ( Country char(3) NOT NULL default '', Language char(30) NOT NULL default '', Percentage float(3,1) NOT NULL default '0.0', PRIMARY KEY (Country, Language), INDEX (Percentage) ); DROP INDEX Country ON City; CREATE INDEX CountryName ON City(Country,Name); CREATE INDEX Name ON City(Name); select * from City where Country='FIN' AND Name IN ('Lahti','Imatra') OR Country='RUS' AND Name IN ('St Petersburg', 'Moscow') OR Country='SWE' AND Name IN ('Stockholm', 'Uppsala') OR Country='DEU' AND Name IN ('Berlin', 'Bonn') OR Country='BEL' AND Name IN ('Antwerpen', 'Gent') OR Country='PRT' AND Name IN ('Braga', 'Porto') OR Country='FRA' AND Name IN ('Paris', 'Marcel') OR Country='POL' AND Name IN ('Warszawa', 'Wroclaw') OR Country='NOR' AND Name IN ('Oslo', 'Bergen') OR Country='ITA' AND Name IN ('Napoli', 'Venezia'); ID Name Country Population 175 Antwerpen BEL 446525 176 Gent BEL 224180 3068 Berlin DEU 3386667 3087 Bonn DEU 301048 3242 Lahti FIN 96921 2974 Paris FRA 2125246 1466 Napoli ITA 1002619 1474 Venezia ITA 277305 2808 Bergen NOR 230948 2807 Oslo NOR 508726 2928 Warszawa POL 1615369 2931 Wroclaw POL 636765 2918 Braga PRT 90535 2915 Porto PRT 273060 3580 Moscow RUS 8389200 3581 St Petersburg RUS 4694000 3048 Stockholm SWE 750348 3051 Uppsala SWE 189569 explain select * from City where Country='FIN' AND Name IN ('Lahti','Imatra') OR Country='RUS' AND Name IN ('St Petersburg', 'Moscow') OR Country='SWE' AND Name IN ('Stockholm', 'Uppsala') OR Country='DEU' AND Name IN ('Berlin', 'Bonn') OR Country='BEL' AND Name IN ('Antwerpen', 'Gent') OR Country='PRT' AND Name IN ('Braga', 'Porto') OR Country='FRA' AND Name IN ('Paris', 'Marcel') OR Country='POL' AND Name IN ('Warszawa', 'Wroclaw') OR Country='NOR' AND Name IN ('Oslo', 'Bergen') OR Country='ITA' AND Name IN ('Napoli', 'Venezia'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City range CountryName,Name CountryName 38 NULL 22 Using index condition; Using where DROP DATABASE world; set session optimizer_switch='index_merge_sort_intersection=default';