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|
DROP TABLE IF EXISTS t1;
CREATE TABLE t1
(
key1 INT NOT NULL,
key2 INT NOT NULL,
key3 INT NOT NULL,
key4 INT NOT NULL,
key5 INT,
key6 INT,
key7 INT NOT NULL,
key8 INT NOT NULL,
INDEX i1(key1),
INDEX i2(key2),
INDEX i3(key3),
INDEX i4(key4),
INDEX i5(key5),
INDEX i6(key6)
);
ANALYZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 analyze status OK
DROP TABLE IF EXISTS t2;
CREATE TABLE t2 LIKE t1;
INSERT INTO t2 SELECT * FROM t1;
ANALYZE TABLE t2;
Table Op Msg_type Msg_text
test.t2 analyze status Table is already up to date
EXPLAIN DELETE FROM t1 WHERE key1=25 OR key4=10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i4 i1,i4 4,4 NULL # Using union(i1,i4); Using where
SELECT COUNT(*) FROM t1 WHERE key1=25 OR key4=10;
COUNT(*)
3
DELETE FROM t1 WHERE key1=25 OR key4=10;
SELECT COUNT(*) FROM t1 WHERE key1=25 OR key4=10;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key1=48 OR key4=2 OR key6=3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i4,i6 i1,i4,i6 4,4,5 NULL # Using union(i1,i4,i6); Using where
SELECT COUNT(*) FROM t1 WHERE key1=48 OR key4=2 OR key6=3;
COUNT(*)
4
DELETE FROM t1 WHERE key1=48 OR key4=2 OR key6=3;
SELECT COUNT(*) FROM t1 WHERE key1=48 OR key4=2 OR key6=3;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key3=1025 OR key5 IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i3,i5 i3,i5 4,5 NULL # Using union(i3,i5); Using where
SELECT COUNT(*) FROM t1 WHERE key3=1025 OR key5 IS NULL;
COUNT(*)
8
DELETE FROM t1 WHERE key3=1025 OR key5 IS NULL;
SELECT COUNT(*) FROM t1 WHERE key3=1025 OR key5 IS NULL;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key3=45 OR key1=6 OR key6 IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i3,i6 i3,i1,i6 4,4,5 NULL # Using union(i3,i1,i6); Using where
SELECT COUNT(*) FROM t1 WHERE key3=45 OR key1=6 OR key6 IS NULL;
COUNT(*)
2
DELETE FROM t1 WHERE key3=45 OR key1=6 OR key6 IS NULL;
SELECT COUNT(*) FROM t1 WHERE key3=45 OR key1=6 OR key6 IS NULL;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE (key4=42 AND key6 IS NOT NULL) OR (key1=4 AND key3=6);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i3,i4,i6 i4,i3 4,4 NULL # Using union(i4,i3); Using where
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6 IS NOT NULL) OR (key1=4 AND key3=6);
COUNT(*)
1
DELETE FROM t1 WHERE (key4=42 AND key6 IS NOT NULL) OR (key1=4 AND key3=6);
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6 IS NOT NULL) OR (key1=4 AND key3=6);
COUNT(*)
0
INSERT INTO t1 VALUES (42,42,42,42,3,3,3,3),(4,4,6,6,6,6,4,4);
EXPLAIN DELETE FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i3,i4,i6 i4,i3,i1 4,4,4 NULL # Using union(i4,intersect(i3,i1)); Using where
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6);
COUNT(*)
2
DELETE FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6);
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6);
COUNT(*)
0
INSERT INTO t1 VALUES (42,42,42,42,3,3,3,3),(4,4,6,6,6,6,4,4);
EXPLAIN DELETE FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6) AND key5<>50;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i3,i4,i5,i6 i4,i3,i1 4,4,4 NULL # Using union(i4,intersect(i3,i1)); Using where
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6) AND key5<>50;
COUNT(*)
2
DELETE FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6) AND key5<>50;
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6) AND key5<>50;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key1<2 OR key2<3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i2,i1 i2,i1 4,4 NULL # Using sort_union(i2,i1); Using where
SELECT COUNT(*) FROM t1 WHERE key1<2 OR key2<3;
COUNT(*)
1
DELETE FROM t1 WHERE key1<2 OR key2<3;
SELECT COUNT(*) FROM t1 WHERE key1<2 OR key2<3;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key1<5 OR key3<7;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i3,i1 i3,i1 4,4 NULL # Using sort_union(i3,i1); Using where
SELECT COUNT(*) FROM t1 WHERE key1<5 OR key3<7;
COUNT(*)
2
DELETE FROM t1 WHERE key1<5 OR key3<7;
SELECT COUNT(*) FROM t1 WHERE key1<5 OR key3<7;
COUNT(*)
0
INSERT INTO t1 VALUES (10,10,10,10,10,10,10,10),(3,3,3,3,3,3,3,3);
EXPLAIN DELETE FROM t1 WHERE key2=10 OR key3=3 OR key4 IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i2,i3 i2,i3 4,4 NULL # Using union(i2,i3); Using where
SELECT COUNT(*) FROM t1 WHERE key2=10 OR key3=3 OR key4 IS NULL;
COUNT(*)
2
DELETE FROM t1 WHERE key2=10 OR key3=3 OR key4 IS NULL;
SELECT COUNT(*) FROM t1 WHERE key2=10 OR key3=3 OR key4 IS NULL;
COUNT(*)
0
INSERT INTO t1 VALUES (10,10,10,10,10,10,10,10),(3,3,3,3,3,3,3,3);
EXPLAIN DELETE FROM t1 WHERE key2=10 OR key3=3 OR key4 <=> null;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i2,i3 i2,i3 4,4 NULL # Using union(i2,i3); Using where
SELECT COUNT(*) FROM t1 WHERE key2=10 OR key3=3 OR key4 <=> null;
COUNT(*)
2
DELETE FROM t1 WHERE key2=10 OR key3=3 OR key4 <=> null;
SELECT COUNT(*) FROM t1 WHERE key2=10 OR key3=3 OR key4 <=> null;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2 i1,i2 4,4 NULL # Using sort_union(i1,i2); Using where
SELECT COUNT(*) FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40);
COUNT(*)
9
DELETE FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40);
SELECT COUNT(*) FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40);
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2 i1,i2 4,4 NULL # Using sort_union(i1,i2); Using where
SELECT COUNT(*) FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40;
COUNT(*)
2
DELETE FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40;
SELECT COUNT(*) FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40) OR (key3>20 AND key3<45);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2,i3 i1,i2,i3 4,4,4 NULL # Using sort_union(i1,i2,i3); Using where
SELECT COUNT(*) FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40) OR (key3>20 AND key3<45);
COUNT(*)
11
DELETE FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40) OR (key3>20 AND key3<45);
SELECT COUNT(*) FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40) OR (key3>20 AND key3<45);
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40 OR key3 BETWEEN 20 AND 45;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2,i3 i1,i2,i3 4,4,4 NULL # Using sort_union(i1,i2,i3); Using where
SELECT COUNT(*) FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40 OR key3 BETWEEN 20 AND 45;
COUNT(*)
1
DELETE FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40 OR key3 BETWEEN 20 AND 45;
SELECT COUNT(*) FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40 OR key3 BETWEEN 20 AND 45;
COUNT(*)
0
INSERT INTO t1 VALUES (1,1,1,1,1,1,1,1),(2,2,2,2,2,2,2,2),(3,3,3,3,3,3,3,3),(4,4,4,4,4,4,4,4);
EXPLAIN DELETE FROM t1 WHERE ((key3<4 OR key5<3) AND (key1<3 OR key2<3)) OR (((key3<5 AND key6<5) OR key5<2) AND (key5<4 OR key6<4));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i3,i5 i3,i5 4,5 NULL # Using sort_union(i3,i5); Using where
SELECT COUNT(*) FROM t1 WHERE ((key3<4 OR key5<3) AND (key1<3 OR key2<3)) OR (((key3<5 AND key6<5) OR key5<2) AND (key5<4 OR key6<4));
COUNT(*)
3
DELETE FROM t1 WHERE ((key3<4 OR key5<3) AND (key1<3 OR key2<3)) OR (((key3<5 AND key6<5) OR key5<2) AND (key5<4 OR key6<4));
SELECT COUNT(*) FROM t1 WHERE ((key3<4 OR key5<3) AND (key1<3 OR key2<3)) OR (((key3<5 AND key6<5) OR key5<2) AND (key5<4 OR key6<4));
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE (key4<42 AND key6 IS NOT NULL) OR (key1>4 AND key5 IS NULL) AND key2<>50;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2,i4,i5,i6 i4,i5 4,5 NULL # Using sort_union(i4,i5); Using where
SELECT COUNT(*) FROM t1 WHERE (key4<42 AND key6 IS NOT NULL) OR (key1>4 AND key5 IS NULL) AND key2<>50;
COUNT(*)
13
DELETE FROM t1 WHERE (key4<42 AND key6 IS NOT NULL) OR (key1>4 AND key5 IS NULL) AND key2<>50;
SELECT COUNT(*) FROM t1 WHERE (key4<42 AND key6 IS NOT NULL) OR (key1>4 AND key5 IS NULL) AND key2<>50;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE (key5 IN (15,70) OR key6 IN (15,70)) ;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i5,i6 i5,i6 5,5 NULL # Using sort_union(i5,i6); Using where
SELECT COUNT(*) FROM t1 WHERE (key5 IN (15,70) OR key6 IN (15,70)) ;
COUNT(*)
1
DELETE FROM t1 WHERE (key5 IN (15,70) OR key6 IN (15,70)) ;
SELECT COUNT(*) FROM t1 WHERE (key5 IN (15,70) OR key6 IN (15,70)) ;
COUNT(*)
0
INSERT INTO t1 VALUES (1,1,1,1,1,1,1,1),(2,2,2,2,2,2,2,2),(3,3,3,3,3,3,3,3);
EXPLAIN DELETE FROM t1 WHERE key1<2 OR key2<3 ORDER BY key1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2 i1,i2 4,4 NULL # Using sort_union(i1,i2); Using where; Using filesort
SELECT COUNT(*) FROM t1 WHERE key1<2 OR key2<3 ORDER BY key1;
COUNT(*)
2
DELETE FROM t1 WHERE key1<2 OR key2<3 ORDER BY key1;
SELECT COUNT(*) FROM t1 WHERE key1<2 OR key2<3 ORDER BY key1;
COUNT(*)
0
EXPLAIN DELETE FROM t1 USING t1 INNER JOIN t2 ON (t2.key1=t2.key1) WHERE t1.key1=3 OR t1.key2=4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2 i1,i2 4,4 NULL # Using union(i1,i2); Using where
1 SIMPLE t2 index NULL i1 4 NULL # Using index; Using join buffer (Block Nested Loop)
SELECT COUNT(*) FROM t1;
COUNT(*)
2001
DELETE FROM t1 USING t1 INNER JOIN t2 ON (t2.key1=t2.key1) WHERE t1.key1=3 OR t1.key2=4;
SELECT COUNT(*) FROM t1;
COUNT(*)
2000
EXPLAIN DELETE FROM t2 WHERE key6 = (SELECT key6 FROM t1 WHERE key1=10 OR key5=3 OR key2 IS NULL) OR key3=28 OR key4=10;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index_merge i3,i4 i3,i4 4,4 NULL # Using union(i3,i4); Using where
2 SUBQUERY t1 index_merge i1,i5 i1,i5 4,5 NULL # Using union(i1,i5); Using where
SELECT COUNT(*) FROM t2 WHERE key6 = (SELECT key6 FROM t1 WHERE key1=10 OR key5=3 OR key2 IS NULL) OR key3=28 OR key4=10;
COUNT(*)
3
DELETE FROM t2 WHERE key6 = (SELECT key6 FROM t1 WHERE key1=10 OR key5=3 OR key2 IS NULL) OR key3=28 OR key4=10;
SELECT COUNT(*) FROM t2 WHERE key6 = (SELECT key6 FROM t1 WHERE key1=10 OR key5=3 OR key2 IS NULL) OR key3=28 OR key4=10;
COUNT(*)
0
EXPLAIN DELETE FROM t2 WHERE key1=25 OR key4=40 AND (key4 < SOME (SELECT key4 FROM t1 WHERE key1<5 OR key4<8) OR key1 < ANY (SELECT key1 FROM t1 WHERE key1<5 OR key4<7) );
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index_merge i1,i4 i1,i4 4,4 NULL # Using union(i1,i4); Using where
3 SUBQUERY t1 index_merge i1,i4 i1,i4 4,4 NULL # Using sort_union(i1,i4); Using where
2 SUBQUERY t1 index_merge i1,i4 i1,i4 4,4 NULL # Using sort_union(i1,i4); Using where
SELECT COUNT(*) FROM t2 WHERE key1=25 OR key4=40 AND (key4 < SOME (SELECT key4 FROM t1 WHERE key1<5 OR key4<8) OR key1 < ANY (SELECT key1 FROM t1 WHERE key1<5 OR key4<7) );
COUNT(*)
1
DELETE FROM t2 WHERE key1=25 OR key4=40 AND (key4 < SOME (SELECT key4 FROM t1 WHERE key1<5 OR key4<8) OR key1 < ANY (SELECT key1 FROM t1 WHERE key1<5 OR key4<7) );
SELECT COUNT(*) FROM t2 WHERE key1=25 OR key4=40 AND (key4 < SOME (SELECT key4 FROM t1 WHERE key1<5 OR key4<8) OR key1 < ANY (SELECT key1 FROM t1 WHERE key1<5 OR key4<7) );
COUNT(*)
0
INSERT INTO t1 VALUES (2,2,2,2,2,2,2,2),(5,5,5,5,5,5,5,5);
EXPLAIN DELETE FROM t2 WHERE EXISTS (SELECT * FROM t1 WHERE key1<5 OR key3<7);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL # Deleting all rows
2 SUBQUERY t1 index_merge i1,i3 i1,i3 4,4 NULL # Using sort_union(i1,i3); Using where
SELECT COUNT(*) FROM t2 WHERE EXISTS (SELECT * FROM t1 WHERE key1<5 OR key3<7);
COUNT(*)
2053
DELETE FROM t2 WHERE EXISTS (SELECT * FROM t1 WHERE key1<5 OR key3<7);
SELECT COUNT(*) FROM t2 WHERE EXISTS (SELECT * FROM t1 WHERE key1<5 OR key3<7);
COUNT(*)
0
INSERT INTO t1 VALUES ( 3,3,3,3,3,3,3,3 ),(4,4,4,4,4,4,4,4);
EXPLAIN DELETE FROM t1 WHERE key7 = 3 OR key8 = 4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL # Using where
SELECT COUNT(*) FROM t1 WHERE key7 = 3 OR key8 = 4;
COUNT(*)
2
DELETE FROM t1 WHERE key7 = 3 OR key8 = 4;
SELECT COUNT(*) FROM t1 WHERE key7 = 3 OR key8 = 4;
COUNT(*)
0
DROP TABLE IF EXISTS t1;
CREATE TABLE t1
(
key1 INT NOT NULL,
key2 INT NOT NULL,
key3 INT NOT NULL,
key4 INT NOT NULL,
key5 INT,
key6 INT,
key7 INT NOT NULL,
key8 INT NOT NULL,
INDEX i1(key1,key2),
INDEX i2(key2,key1),
INDEX i3(key3,key4),
INDEX i4(key4,key3),
INDEX i5(key5,key6),
INDEX i6(key6,key5),
INDEX i7(key7,key8),
INDEX i8(key8,key7)
);
ANALYZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 analyze status OK
DROP TABLE IF EXISTS t2;
CREATE TABLE t2 LIKE t1;
INSERT INTO t2 SELECT * FROM t1;
ANALYZE TABLE t2;
Table Op Msg_type Msg_text
test.t2 analyze status Table is already up to date
EXPLAIN DELETE FROM t1 WHERE key1=25 OR key4=10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i4 i1,i4 4,4 NULL # Using sort_union(i1,i4); Using where
SELECT COUNT(*) FROM t1 WHERE key1=25 OR key4=10;
COUNT(*)
3
DELETE FROM t1 WHERE key1=25 OR key4=10;
SELECT COUNT(*) FROM t1 WHERE key1=25 OR key4=10;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key1=48 OR key4=2 OR key6=3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i4,i6 i1,i4,i6 4,4,5 NULL # Using sort_union(i1,i4,i6); Using where
SELECT COUNT(*) FROM t1 WHERE key1=48 OR key4=2 OR key6=3;
COUNT(*)
4
DELETE FROM t1 WHERE key1=48 OR key4=2 OR key6=3;
SELECT COUNT(*) FROM t1 WHERE key1=48 OR key4=2 OR key6=3;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key3=1025 OR key5 IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i3,i5 i3,i5 4,5 NULL # Using sort_union(i3,i5); Using where
SELECT COUNT(*) FROM t1 WHERE key3=1025 OR key5 IS NULL;
COUNT(*)
8
DELETE FROM t1 WHERE key3=1025 OR key5 IS NULL;
SELECT COUNT(*) FROM t1 WHERE key3=1025 OR key5 IS NULL;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key3=45 OR key1=6 OR key6 IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i3,i6 i3,i1,i6 4,4,5 NULL # Using sort_union(i3,i1,i6); Using where
SELECT COUNT(*) FROM t1 WHERE key3=45 OR key1=6 OR key6 IS NULL;
COUNT(*)
2
DELETE FROM t1 WHERE key3=45 OR key1=6 OR key6 IS NULL;
SELECT COUNT(*) FROM t1 WHERE key3=45 OR key1=6 OR key6 IS NULL;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE (key4=42 AND key6 IS NOT NULL) OR (key1=4 AND key3=6);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i3,i4,i6 i4,i3 4,4 NULL # Using sort_union(i4,i3); Using where
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6 IS NOT NULL) OR (key1=4 AND key3=6);
COUNT(*)
1
DELETE FROM t1 WHERE (key4=42 AND key6 IS NOT NULL) OR (key1=4 AND key3=6);
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6 IS NOT NULL) OR (key1=4 AND key3=6);
COUNT(*)
0
INSERT INTO t1 VALUES (42,42,42,42,3,3,3,3),(4,4,6,6,6,6,4,4);
EXPLAIN DELETE FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i3,i4,i6 i6,i1 5,4 NULL # Using sort_union(i6,i1); Using where
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6);
COUNT(*)
2
DELETE FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6);
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6);
COUNT(*)
0
INSERT INTO t1 VALUES (42,42,42,42,3,3,3,3),(4,4,6,6,6,6,4,4);
EXPLAIN DELETE FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6) AND key5<>50;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i3,i4,i5,i6 i6,i1 5,4 NULL # Using sort_union(i6,i1); Using where
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6) AND key5<>50;
COUNT(*)
2
DELETE FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6) AND key5<>50;
SELECT COUNT(*) FROM t1 WHERE (key4=42 AND key6=3) OR (key1=4 AND key3=6) AND key5<>50;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key1<2 OR key2<3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i2,i1 i2,i1 4,4 NULL # Using sort_union(i2,i1); Using where
SELECT COUNT(*) FROM t1 WHERE key1<2 OR key2<3;
COUNT(*)
1
DELETE FROM t1 WHERE key1<2 OR key2<3;
SELECT COUNT(*) FROM t1 WHERE key1<2 OR key2<3;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key1<5 OR key3<7;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i3,i1 i3,i1 4,4 NULL # Using sort_union(i3,i1); Using where
SELECT COUNT(*) FROM t1 WHERE key1<5 OR key3<7;
COUNT(*)
2
DELETE FROM t1 WHERE key1<5 OR key3<7;
SELECT COUNT(*) FROM t1 WHERE key1<5 OR key3<7;
COUNT(*)
0
INSERT INTO t1 VALUES (10,10,10,10,10,10,10,10),(3,3,3,3,3,3,3,3);
EXPLAIN DELETE FROM t1 WHERE key2=10 OR key3=3 OR key4 IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i2,i3 i2,i3 4,4 NULL # Using sort_union(i2,i3); Using where
SELECT COUNT(*) FROM t1 WHERE key2=10 OR key3=3 OR key4 IS NULL;
COUNT(*)
2
DELETE FROM t1 WHERE key2=10 OR key3=3 OR key4 IS NULL;
SELECT COUNT(*) FROM t1 WHERE key2=10 OR key3=3 OR key4 IS NULL;
COUNT(*)
0
INSERT INTO t1 VALUES (10,10,10,10,10,10,10,10),(3,3,3,3,3,3,3,3);
EXPLAIN DELETE FROM t1 WHERE key2=10 OR key3=3 OR key4 <=> null;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i2,i3 i2,i3 4,4 NULL # Using sort_union(i2,i3); Using where
SELECT COUNT(*) FROM t1 WHERE key2=10 OR key3=3 OR key4 <=> null;
COUNT(*)
2
DELETE FROM t1 WHERE key2=10 OR key3=3 OR key4 <=> null;
SELECT COUNT(*) FROM t1 WHERE key2=10 OR key3=3 OR key4 <=> null;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2 i1,i2 4,4 NULL # Using sort_union(i1,i2); Using where
SELECT COUNT(*) FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40);
COUNT(*)
9
DELETE FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40);
SELECT COUNT(*) FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40);
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2 i1,i2 4,4 NULL # Using sort_union(i1,i2); Using where
SELECT COUNT(*) FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40;
COUNT(*)
2
DELETE FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40;
SELECT COUNT(*) FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40) OR (key3>20 AND key3<45);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2,i3 i1,i2,i3 4,4,4 NULL # Using sort_union(i1,i2,i3); Using where
SELECT COUNT(*) FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40) OR (key3>20 AND key3<45);
COUNT(*)
11
DELETE FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40) OR (key3>20 AND key3<45);
SELECT COUNT(*) FROM t1 WHERE (key1>30 AND key1<35) OR (key2>32 AND key2<40) OR (key3>20 AND key3<45);
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40 OR key3 BETWEEN 20 AND 45;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2,i3 i1,i2,i3 4,4,4 NULL # Using sort_union(i1,i2,i3); Using where
SELECT COUNT(*) FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40 OR key3 BETWEEN 20 AND 45;
COUNT(*)
1
DELETE FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40 OR key3 BETWEEN 20 AND 45;
SELECT COUNT(*) FROM t1 WHERE key1 BETWEEN 30 AND 35 OR key2 BETWEEN 32 AND 40 OR key3 BETWEEN 20 AND 45;
COUNT(*)
0
INSERT INTO t1 VALUES (1,1,1,1,1,1,1,1),(2,2,2,2,2,2,2,2),(3,3,3,3,3,3,3,3),(4,4,4,4,4,4,4,4);
EXPLAIN DELETE FROM t1 WHERE ((key3<4 OR key5<3) AND (key1<3 OR key2<3)) OR (((key3<5 AND key6<5) OR key5<2) AND (key5<4 OR key6<4));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i3,i5 i3,i5 4,5 NULL # Using sort_union(i3,i5); Using where
SELECT COUNT(*) FROM t1 WHERE ((key3<4 OR key5<3) AND (key1<3 OR key2<3)) OR (((key3<5 AND key6<5) OR key5<2) AND (key5<4 OR key6<4));
COUNT(*)
3
DELETE FROM t1 WHERE ((key3<4 OR key5<3) AND (key1<3 OR key2<3)) OR (((key3<5 AND key6<5) OR key5<2) AND (key5<4 OR key6<4));
SELECT COUNT(*) FROM t1 WHERE ((key3<4 OR key5<3) AND (key1<3 OR key2<3)) OR (((key3<5 AND key6<5) OR key5<2) AND (key5<4 OR key6<4));
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE (key4<42 AND key6 IS NOT NULL) OR (key1>4 AND key5 IS NULL) AND key2<>50;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2,i4,i5,i6 i4,i5 4,5 NULL # Using sort_union(i4,i5); Using where
SELECT COUNT(*) FROM t1 WHERE (key4<42 AND key6 IS NOT NULL) OR (key1>4 AND key5 IS NULL) AND key2<>50;
COUNT(*)
13
DELETE FROM t1 WHERE (key4<42 AND key6 IS NOT NULL) OR (key1>4 AND key5 IS NULL) AND key2<>50;
SELECT COUNT(*) FROM t1 WHERE (key4<42 AND key6 IS NOT NULL) OR (key1>4 AND key5 IS NULL) AND key2<>50;
COUNT(*)
0
EXPLAIN DELETE FROM t1 WHERE (key5 IN (15,70) OR key6 IN (15,70)) ;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i5,i6 i5,i6 5,5 NULL # Using sort_union(i5,i6); Using where
SELECT COUNT(*) FROM t1 WHERE (key5 IN (15,70) OR key6 IN (15,70)) ;
COUNT(*)
1
DELETE FROM t1 WHERE (key5 IN (15,70) OR key6 IN (15,70)) ;
SELECT COUNT(*) FROM t1 WHERE (key5 IN (15,70) OR key6 IN (15,70)) ;
COUNT(*)
0
INSERT INTO t1 VALUES (1,1,1,1,1,1,1,1),(2,2,2,2,2,2,2,2),(3,3,3,3,3,3,3,3);
EXPLAIN DELETE FROM t1 WHERE key1<2 OR key2<3 ORDER BY key1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2 i1,i2 4,4 NULL # Using sort_union(i1,i2); Using where; Using filesort
SELECT COUNT(*) FROM t1 WHERE key1<2 OR key2<3 ORDER BY key1;
COUNT(*)
2
DELETE FROM t1 WHERE key1<2 OR key2<3 ORDER BY key1;
SELECT COUNT(*) FROM t1 WHERE key1<2 OR key2<3 ORDER BY key1;
COUNT(*)
0
EXPLAIN DELETE FROM t1 USING t1 INNER JOIN t2 ON (t2.key1=t2.key1) WHERE t1.key1=3 OR t1.key2=4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i1,i2 i1,i2 4,4 NULL # Using sort_union(i1,i2); Using where
1 SIMPLE t2 index NULL i1 8 NULL # Using index; Using join buffer (Block Nested Loop)
SELECT COUNT(*) FROM t1;
COUNT(*)
2001
DELETE FROM t1 USING t1 INNER JOIN t2 ON (t2.key1=t2.key1) WHERE t1.key1=3 OR t1.key2=4;
SELECT COUNT(*) FROM t1;
COUNT(*)
2000
EXPLAIN DELETE FROM t2 WHERE key6 = (SELECT key6 FROM t1 WHERE key1=10 OR key5=3 OR key2 IS NULL) OR key3=28 OR key4=10;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index_merge i3,i4 i3,i4 4,4 NULL # Using sort_union(i3,i4); Using where
2 SUBQUERY t1 index_merge i1,i5 i1,i5 4,5 NULL # Using sort_union(i1,i5); Using where
SELECT COUNT(*) FROM t2 WHERE key6 = (SELECT key6 FROM t1 WHERE key1=10 OR key5=3 OR key2 IS NULL) OR key3=28 OR key4=10;
COUNT(*)
3
DELETE FROM t2 WHERE key6 = (SELECT key6 FROM t1 WHERE key1=10 OR key5=3 OR key2 IS NULL) OR key3=28 OR key4=10;
SELECT COUNT(*) FROM t2 WHERE key6 = (SELECT key6 FROM t1 WHERE key1=10 OR key5=3 OR key2 IS NULL) OR key3=28 OR key4=10;
COUNT(*)
0
EXPLAIN DELETE FROM t2 WHERE key1=25 OR key4=40 AND (key4 < SOME (SELECT key4 FROM t1 WHERE key1<5 OR key4<8) OR key1 < ANY (SELECT key1 FROM t1 WHERE key1<5 OR key4<7) );
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index_merge i1,i4 i1,i4 4,4 NULL # Using sort_union(i1,i4); Using where
3 SUBQUERY t1 index_merge i1,i4 i1,i4 4,4 NULL # Using sort_union(i1,i4); Using where
2 SUBQUERY t1 index_merge i1,i4 i1,i4 4,4 NULL # Using sort_union(i1,i4); Using where
SELECT COUNT(*) FROM t2 WHERE key1=25 OR key4=40 AND (key4 < SOME (SELECT key4 FROM t1 WHERE key1<5 OR key4<8) OR key1 < ANY (SELECT key1 FROM t1 WHERE key1<5 OR key4<7) );
COUNT(*)
1
DELETE FROM t2 WHERE key1=25 OR key4=40 AND (key4 < SOME (SELECT key4 FROM t1 WHERE key1<5 OR key4<8) OR key1 < ANY (SELECT key1 FROM t1 WHERE key1<5 OR key4<7) );
SELECT COUNT(*) FROM t2 WHERE key1=25 OR key4=40 AND (key4 < SOME (SELECT key4 FROM t1 WHERE key1<5 OR key4<8) OR key1 < ANY (SELECT key1 FROM t1 WHERE key1<5 OR key4<7) );
COUNT(*)
0
INSERT INTO t1 VALUES (2,2,2,2,2,2,2,2),(5,5,5,5,5,5,5,5);
EXPLAIN DELETE FROM t2 WHERE EXISTS (SELECT * FROM t1 WHERE key1<5 OR key3<7);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL # Deleting all rows
2 SUBQUERY t1 index_merge i1,i3 i1,i3 4,4 NULL # Using sort_union(i1,i3); Using where
SELECT COUNT(*) FROM t2 WHERE EXISTS (SELECT * FROM t1 WHERE key1<5 OR key3<7);
COUNT(*)
2053
DELETE FROM t2 WHERE EXISTS (SELECT * FROM t1 WHERE key1<5 OR key3<7);
SELECT COUNT(*) FROM t2 WHERE EXISTS (SELECT * FROM t1 WHERE key1<5 OR key3<7);
COUNT(*)
0
INSERT INTO t1 VALUES ( 3,3,3,3,3,3,3,3 ),(4,4,4,4,4,4,4,4);
EXPLAIN DELETE FROM t1 WHERE key7 = 3 OR key8 = 4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index_merge i7,i8 i7,i8 4,4 NULL # Using sort_union(i7,i8); Using where
SELECT COUNT(*) FROM t1 WHERE key7 = 3 OR key8 = 4;
COUNT(*)
2
DELETE FROM t1 WHERE key7 = 3 OR key8 = 4;
SELECT COUNT(*) FROM t1 WHERE key7 = 3 OR key8 = 4;
COUNT(*)
0
DROP TABLE t1;
DROP TABLE t2;
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