--source include/default_optimizer_switch.inc --source include/default_charset.inc --disable_warnings DROP TABLE IF EXISTS t1,t2,t3,t4; DROP DATABASE IF EXISTS world; --enable_warnings set names utf8; CREATE DATABASE world; use world; --source include/world_schema.inc --disable_query_log --disable_result_log --disable_warnings --source include/world.inc --enable_warnings --enable_result_log --enable_query_log SELECT COUNT(*) FROM Country; SELECT COUNT(*) FROM City; SELECT COUNT(*) FROM CountryLanguage; CREATE INDEX Name ON City(Name); --disable_query_log --disable_result_log --disable_warnings ANALYZE TABLE City; --enable_warnings --enable_result_log --enable_query_log SET SESSION optimizer_switch='rowid_filter=off'; SET SESSION optimizer_switch='index_merge_sort_intersection=on'; SELECT COUNT(*) FROM City; # The output of the next 6 queries tells us about selectivities # of the conditions utilized in 4 queries following after them SELECT COUNT(*) FROM City WHERE Name LIKE 'C%'; SELECT COUNT(*) FROM City WHERE Name LIKE 'M%'; SELECT COUNT(*) FROM City WHERE Population > 1000000; SELECT COUNT(*) FROM City WHERE Population > 1500000; SELECT COUNT(*) FROM City WHERE Population > 300000; SELECT COUNT(*) FROM City WHERE Population > 7000000; # The pattern of the WHERE condition used in the following 4 queries is # range(key1) AND range(key2) # Varying values of the constants in the conjuncts of the condition # we can get either an index intersection retrieval over key1 and key2 # or a range index scan for one of these indexes --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Name LIKE 'C%' AND Population > 1000000; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Name LIKE 'M%' AND Population > 1500000; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Name LIKE 'M%' AND Population > 300000; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Name LIKE 'M%' AND Population > 7000000; # The following 8 queries check that # the previous 4 plans are valid and return # the correct results when executed --sorted_result SELECT * FROM City USE INDEX () WHERE Name LIKE 'C%' AND Population > 1000000; --sorted_result SELECT * FROM City WHERE Name LIKE 'C%' AND Population > 1000000; --sorted_result SELECT * FROM City USE INDEX () WHERE Name LIKE 'M%' AND Population > 1500000; --sorted_result SELECT * FROM City WHERE Name LIKE 'M%' AND Population > 1500000; --sorted_result SELECT * FROM City USE INDEX () WHERE Name LIKE 'M%' AND Population > 300000; --sorted_result SELECT * FROM City WHERE Name LIKE 'M%' AND Population > 300000; SELECT * FROM City USE INDEX () WHERE Name LIKE 'M%' AND Population > 7000000; SELECT * FROM City WHERE Name LIKE 'M%' AND Population > 7000000; # The output of the next 7 queries tells us about selectivities # of the conditions utilized in 3 queries following after them SELECT COUNT(*) FROM City WHERE Name BETWEEN 'M' AND 'N'; SELECT COUNT(*) FROM City WHERE Name BETWEEN 'G' AND 'J'; SELECT COUNT(*) FROM City WHERE Name BETWEEN 'G' AND 'K'; SELECT COUNT(*) FROM City WHERE Population > 1000000; SELECT COUNT(*) FROM City WHERE Population > 500000; SELECT COUNT(*) FROM City WHERE Country LIKE 'C%'; SELECT COUNT(*) FROM City WHERE Country LIKE 'B%'; SELECT COUNT(*) FROM City WHERE Country LIKE 'J%'; # The pattern of the WHERE condition used in the following 3 queries is # range(key1) AND range(key2) AND range(key3) # Varying values of the constants in the conjuncts of the condition # we can get index intersection over different pairs of keys: # over(key1,key2), over(key1,key3) and over(key2,key3) --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Name BETWEEN 'M' AND 'N' AND Population > 1000000 AND Country LIKE 'C%'; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Name BETWEEN 'G' AND 'J' AND Population > 1000000 AND Country LIKE 'J%'; --replace_column 7 # 9 # --replace_result Population,Country,Name Population,Name,Country EXPLAIN SELECT * FROM City WHERE Name BETWEEN 'G' AND 'K' AND Population > 500000 AND Country LIKE 'C%'; # The following 6 queries check that # the previous 3 plans are valid and return # the correct results when executed SELECT * FROM City USE INDEX () WHERE Name BETWEEN 'M' AND 'N' AND Population > 1000000 AND Country LIKE 'C%'; SELECT * FROM City WHERE Name BETWEEN 'M' AND 'N' AND Population > 1000000 AND Country LIKE 'C%'; SELECT * FROM City USE INDEX () WHERE Name BETWEEN 'G' AND 'J' AND Population > 1000000 AND Country LIKE 'J%'; --sorted_result SELECT * FROM City WHERE Name BETWEEN 'G' AND 'J' AND Population > 1000000 AND Country LIKE 'J%'; SELECT * FROM City USE INDEX () WHERE Name BETWEEN 'G' AND 'K' AND Population > 500000 AND Country LIKE 'C%'; --sorted_result SELECT * FROM City WHERE Name BETWEEN 'G' AND 'K' AND Population > 500000 AND Country LIKE 'C%'; # The output of the next 12 queries tells us about selectivities # of the conditions utilized in 5 queries following after them SELECT COUNT(*) FROM City WHERE ID BETWEEN 501 AND 1000; SELECT COUNT(*) FROM City WHERE ID BETWEEN 1 AND 500; SELECT COUNT(*) FROM City WHERE ID BETWEEN 2001 AND 2500; SELECT COUNT(*) FROM City WHERE ID BETWEEN 3701 AND 4000; SELECT COUNT(*) FROM City WHERE Population > 700000; SELECT COUNT(*) FROM City WHERE Population > 1000000; SELECT COUNT(*) FROM City WHERE Population > 300000; SELECT COUNT(*) FROM City WHERE Population > 600000; SELECT COUNT(*) FROM City WHERE Country LIKE 'C%'; SELECT COUNT(*) FROM City WHERE Country LIKE 'A%'; SELECT COUNT(*) FROM City WHERE Country LIKE 'H%'; SELECT COUNT(*) FROM City WHERE Country BETWEEN 'S' AND 'Z'; # The pattern of the WHERE condition used in the following 5 queries is # range(key1) AND range(key2) AND range(key3) # with key1 happens to be a primary key (it matters only for InnoDB) # Varying values of the constants in the conjuncts of the condition # we can get index intersection either over all three keys, or over # different pairs, or a range scan over one of these keys. # Bear in mind that the condition (Country LIKE 'A%') is actually # equivalent to the condition (Country BETWEEN 'A' AND 'B') for the # tested instance the table City. --replace_column 9 # EXPLAIN SELECT * FROM City WHERE ID BETWEEN 501 AND 1000 AND Population > 700000 AND Country LIKE 'C%'; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE ID BETWEEN 1 AND 500 AND Population > 700000 AND Country LIKE 'C%'; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE ID BETWEEN 2001 AND 2500 AND Population > 300000 AND Country LIKE 'H%'; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE ID BETWEEN 3701 AND 4000 AND Population > 1000000 AND Country BETWEEN 'S' AND 'Z'; --replace_column 9 # --replace_result PRIMARY,Country,Population PRIMARY,Population,Country 4,7,4 4,4,7 EXPLAIN SELECT * FROM City WHERE ID BETWEEN 3001 AND 4000 AND Population > 600000 AND Country BETWEEN 'S' AND 'Z' ; # The following 10 queries check that # the previous 5 plans are valid and return # the correct results when executed SELECT * FROM City USE INDEX () WHERE ID BETWEEN 501 AND 1000 AND Population > 700000 AND Country LIKE 'C%'; SELECT * FROM City WHERE ID BETWEEN 501 AND 1000 AND Population > 700000 AND Country LIKE 'C%'; --sorted_result SELECT * FROM City USE INDEX () WHERE ID BETWEEN 1 AND 500 AND Population > 700000 AND Country LIKE 'C%'; --sorted_result SELECT * FROM City WHERE ID BETWEEN 1 AND 500 AND Population > 700000 AND Country LIKE 'C%'; SELECT * FROM City USE INDEX () WHERE ID BETWEEN 2001 AND 2500 AND Population > 300000 AND Country LIKE 'H%'; SELECT * FROM City WHERE ID BETWEEN 2001 AND 2500 AND Population > 300000 AND Country LIKE 'H%'; --sorted_result SELECT * FROM City USE INDEX () WHERE ID BETWEEN 3701 AND 4000 AND Population > 700000 AND Country BETWEEN 'S' AND 'Z'; --sorted_result SELECT * FROM City WHERE ID BETWEEN 3701 AND 4000 AND Population > 700000 AND Country BETWEEN 'S' AND 'Z'; --sorted_result SELECT * FROM City USE INDEX () WHERE ID BETWEEN 3001 AND 4000 AND Population > 600000 AND Country BETWEEN 'S' AND 'Z' ; --sorted_result SELECT * FROM City WHERE ID BETWEEN 3001 AND 4000 AND Population > 600000 AND Country BETWEEN 'S' AND 'Z' ; SET SESSION sort_buffer_size = 2048; # The following EXPLAIN command demonstrate that the execution plans # may be different if sort_buffer_size is set to a small value --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Name LIKE 'C%' AND Population > 1000000; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Name LIKE 'M%' AND Population > 1500000; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Name BETWEEN 'G' AND 'J' AND Population > 1000000 AND Country LIKE 'J%'; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Name BETWEEN 'G' AND 'J' AND Population > 500000 AND Country LIKE 'C%'; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE ID BETWEEN 1 AND 500 AND Population > 700000 AND Country LIKE 'C%'; --replace_column 9 # --replace_result PRIMARY,Country,Population PRIMARY,Population,Country 4,7,4 4,4,7 EXPLAIN SELECT * FROM City WHERE ID BETWEEN 3001 AND 4000 AND Population > 600000 AND Country BETWEEN 'S' AND 'Z'; #Yet the query themselves return the correct results in this case as well --sorted_result SELECT * FROM City WHERE Name LIKE 'C%' AND Population > 1000000; --sorted_result SELECT * FROM City WHERE Name LIKE 'M%' AND Population > 1500000; --sorted_result SELECT * FROM City WHERE Name BETWEEN 'G' AND 'J' AND Population > 700000 AND Country LIKE 'J%'; --sorted_result SELECT * FROM City WHERE Name BETWEEN 'G' AND 'J' AND Population > 500000 AND Country LIKE 'C%'; SELECT * FROM City WHERE ID BETWEEN 1 AND 500 AND Population > 700000 AND Country LIKE 'C%'; --sorted_result SELECT * FROM City WHERE ID BETWEEN 3001 AND 4000 AND Population > 600000 AND Country BETWEEN 'S' AND 'Z'; SET SESSION sort_buffer_size = default; # Instead of the index on the column Country create two compound indexes # including this column as the first component DROP INDEX Country ON City; CREATE INDEX CountryID ON City(Country,ID); CREATE INDEX CountryName ON City(Country,Name); --disable_query_log --disable_result_log --disable_warnings ANALYZE TABLE City; --enable_warnings --enable_result_log --enable_query_log # Check that the first component of a compound index can be used for # index intersection, even in the cases when we have a ref access # for this component --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Country LIKE 'M%' AND Population > 1000000; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Country='USA' AND Population > 1000000; --replace_column 9 # EXPLAIN SELECT * FROM City WHERE Country='USA' AND Population > 1500000 AND Name LIKE 'C%'; # Check that the previous 3 plans return the right results when executed --sorted_result SELECT * FROM City USE INDEX () WHERE Country LIKE 'M%' AND Population > 1000000; --sorted_result SELECT * FROM City WHERE Country LIKE 'M%' AND Population > 1000000; --sorted_result SELECT * FROM City USE INDEX () WHERE Country='USA' AND Population > 1000000; --sorted_result SELECT * FROM City WHERE Country='USA' AND Population > 1000000; SELECT * FROM City USE INDEX () WHERE Country='USA' AND Population > 1500000 AND Name LIKE 'C%'; --sorted_result SELECT * FROM City WHERE Country='USA' AND Population > 1500000 AND Name LIKE 'C%'; # # Bug #754521: wrong cost of index intersection leading # to the choice of a suboptimal execution plan # --replace_column 9 # EXPLAIN SELECT * FROM City, Country WHERE City.Name LIKE 'C%' AND City.Population > 1000000 AND Country.Code=City.Country; DROP DATABASE world; use test; # # Bug #684086: crash with EXPLAIN in InnoDB for index intersection # of two indexes one of which is primary # CREATE TABLE t1 ( f1 int, f4 varchar(32), f5 int, PRIMARY KEY (f1), KEY (f4) ); INSERT INTO t1 VALUES (5,'H',1), (9,'g',0), (527,'i',0), (528,'y',1), (529,'S',6), (530,'m',7), (531,'b',2), (532,'N',1), (533,'V',NULL), (534,'l',1), (535,'M',0), (536,'w',1), (537,'j',5), (538,'l',0), (539,'n',2), (540,'m',2), (541,'r',2), (542,'l',2), (543,'h',3),(544,'o',0), (956,'h',0), (957,'g',0), (958,'W',5), (959,'s',3), (960,'w',0), (961,'q',0), (962,'e',NULL), (963,'u',7), (964,'q',1), (965,'N',NULL), (966,'e',0), (967,'t',3), (968,'e',6), (969,'f',NULL), (970,'j',0), (971,'s',3), (972,'I',0), (973,'h',4), (974,'g',1), (975,'s',0), (976,'r',3), (977,'x',1), (978,'v',8), (979,'j',NULL), (980,'z',7), (981,'t',9), (982,'j',5), (983,'u',NULL), (984,'g',6), (985,'w',1), (986,'h',1), (987,'v',0), (988,'v',0), (989,'c',2), (990,'b',7), (991,'z',0), (992,'M',1), (993,'u',2), (994,'r',2), (995,'b',4), (996,'A',2), (997,'u',0), (998,'a',0), (999,'j',2), (1,'I',2); --replace_column 9 # EXPLAIN SELECT * FROM t1 WHERE (f1 < 535 OR f1 > 985) AND ( f4='r' OR f4 LIKE 'a%' ) ; --sorted_result SELECT * FROM t1 WHERE (f1 < 535 OR f1 > 985) AND ( f4='r' OR f4 LIKE 'a%' ) ; DROP TABLE t1; SET SESSION optimizer_switch='index_merge_sort_intersection=on'; SET SESSION optimizer_switch='rowid_filter=default';