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1
by brian
clean slate |
1 |
drop table if exists t0, t1, t2, t10, t11, t12; |
2 |
create table t0 (a int); |
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3 |
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); |
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4 |
create table t1(a int, b int); |
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5 |
insert into t1 values (0,0),(1,1),(2,2); |
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6 |
create table t2 as select * from t1; |
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7 |
create table t11(a int, b int); |
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8 |
create table t10 (pk int, a int, primary key(pk)); |
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9 |
insert into t10 select a,a from t0; |
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10 |
create table t12 like t10; |
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11 |
insert into t12 select * from t10; |
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12 |
Flattened because of dependency, t10=func(t1) |
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13 |
explain select * from t1 where a in (select pk from t10); |
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14 |
id select_type table type possible_keys key key_len ref rows Extra |
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15 |
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 |
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16 |
1 PRIMARY t10 eq_ref PRIMARY PRIMARY 4 test.t1.a 1 Using index |
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17 |
select * from t1 where a in (select pk from t10); |
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18 |
a b |
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19 |
0 0 |
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20 |
1 1 |
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21 |
2 2 |
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22 |
A confluent case of dependency |
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23 |
explain select * from t1 where a in (select a from t10 where pk=12); |
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24 |
id select_type table type possible_keys key key_len ref rows Extra |
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25 |
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 |
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26 |
1 PRIMARY t10 const PRIMARY PRIMARY 4 const 1 Using where |
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27 |
select * from t1 where a in (select a from t10 where pk=12); |
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28 |
a b |
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29 |
An empty table inside |
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30 |
explain select * from t1 where a in (select a from t11); |
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31 |
id select_type table type possible_keys key key_len ref rows Extra |
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32 |
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables |
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33 |
select * from t1 where a in (select a from t11); |
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34 |
a b |
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35 |
explain select * from t1 where a in (select pk from t10) and b in (select pk from t10); |
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36 |
id select_type table type possible_keys key key_len ref rows Extra |
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37 |
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 |
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38 |
1 PRIMARY t10 eq_ref PRIMARY PRIMARY 4 test.t1.a 1 Using index |
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39 |
1 PRIMARY t10 eq_ref PRIMARY PRIMARY 4 test.t1.b 1 Using index |
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40 |
select * from t1 where a in (select pk from t10) and b in (select pk from t10); |
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41 |
a b |
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42 |
0 0 |
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43 |
1 1 |
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44 |
2 2 |
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45 |
flattening a nested subquery |
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46 |
explain select * from t1 where a in (select pk from t10 where t10.a in (select pk from t12)); |
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47 |
id select_type table type possible_keys key key_len ref rows Extra |
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48 |
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 |
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49 |
1 PRIMARY t10 eq_ref PRIMARY PRIMARY 4 test.t1.a 1 |
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50 |
1 PRIMARY t12 eq_ref PRIMARY PRIMARY 4 test.t10.a 1 Using index |
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51 |
select * from t1 where a in (select pk from t10 where t10.a in (select pk from t12)); |
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52 |
a b |
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53 |
0 0 |
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54 |
1 1 |
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55 |
2 2 |
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56 |
flattening subquery w/ several tables |
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57 |
explain extended select * from t1 where a in (select t10.pk from t10, t12 where t12.pk=t10.a); |
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58 |
id select_type table type possible_keys key key_len ref rows filtered Extra |
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59 |
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 100.00 |
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60 |
1 PRIMARY t10 eq_ref PRIMARY PRIMARY 4 test.t1.a 1 100.00 |
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61 |
1 PRIMARY t12 eq_ref PRIMARY PRIMARY 4 test.t10.a 1 100.00 Using index |
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62 |
Warnings: |
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63 |
Note 1003 select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from (`test`.`t10` join `test`.`t12`) join `test`.`t1` where ((`test`.`t10`.`pk` = `test`.`t1`.`a`) and (`test`.`t12`.`pk` = `test`.`t10`.`a`)) |
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64 |
subqueries within outer joins go into ON expr. |
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65 |
explAin extended |
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66 |
select * from t1 left join (t2 A, t2 B) on ( A.A= t1.A And B.A in (select pk from t10)); |
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67 |
id select_type tABle type possiBle_keys key key_len ref rows filtered ExtrA |
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68 |
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 100.00 |
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69 |
1 PRIMARY A ALL NULL NULL NULL NULL 3 100.00 |
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70 |
1 PRIMARY B ALL NULL NULL NULL NULL 3 100.00 |
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71 |
1 PRIMARY t10 eq_ref PRIMARY PRIMARY 4 test.B.A 1 100.00 Using index |
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72 |
Warnings: |
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73 |
Note 1003 select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`A`.`A` AS `A`,`test`.`A`.`B` AS `B`,`test`.`B`.`A` AS `A`,`test`.`B`.`B` AS `B` from `test`.`t1` left join ((`test`.`t10`) join `test`.`t2` `A` join `test`.`t2` `B`) on(((`test`.`A`.`A` = `test`.`t1`.`A`) And 1 And (`test`.`B`.`A` = `test`.`t10`.`pk`))) where 1 |
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74 |
t2 should be wrapped into OJ-nest, so we have "t1 LJ (t2 J t10)" |
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75 |
explAin extended |
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76 |
select * from t1 left join t2 on (t2.A= t1.A And t2.A in (select pk from t10)); |
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77 |
id select_type tABle type possiBle_keys key key_len ref rows filtered ExtrA |
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78 |
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 100.00 |
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79 |
1 PRIMARY t2 ALL NULL NULL NULL NULL 3 100.00 |
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80 |
1 PRIMARY t10 eq_ref PRIMARY PRIMARY 4 test.t2.A 1 100.00 Using index |
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81 |
Warnings: |
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82 |
Note 1003 select `test`.`t1`.`A` AS `A`,`test`.`t1`.`B` AS `B`,`test`.`t2`.`A` AS `A`,`test`.`t2`.`B` AS `B` from `test`.`t1` left join ((`test`.`t10`) join `test`.`t2`) on(((`test`.`t2`.`A` = `test`.`t1`.`A`) And 1 And (`test`.`t2`.`A` = `test`.`t10`.`pk`))) where 1 |
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83 |
we shouldn't flatten if we're going to get a join of > MAX_TABLES. |
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84 |
explain select * from |
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85 |
t1 s00, t1 s01, t1 s02, t1 s03, t1 s04,t1 s05,t1 s06,t1 s07,t1 s08,t1 s09, |
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86 |
t1 s10, t1 s11, t1 s12, t1 s13, t1 s14,t1 s15,t1 s16,t1 s17,t1 s18,t1 s19, |
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87 |
t1 s20, t1 s21, t1 s22, t1 s23, t1 s24,t1 s25,t1 s26,t1 s27,t1 s28,t1 s29, |
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88 |
t1 s30, t1 s31, t1 s32, t1 s33, t1 s34,t1 s35,t1 s36,t1 s37,t1 s38,t1 s39, |
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89 |
t1 s40, t1 s41, t1 s42, t1 s43, t1 s44,t1 s45,t1 s46,t1 s47,t1 s48,t1 s49 |
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90 |
where
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91 |
s00.a in ( |
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92 |
select m00.a from |
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93 |
t1 m00, t1 m01, t1 m02, t1 m03, t1 m04,t1 m05,t1 m06,t1 m07,t1 m08,t1 m09, |
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94 |
t1 m10, t1 m11, t1 m12, t1 m13, t1 m14,t1 m15,t1 m16,t1 m17,t1 m18,t1 m19 |
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95 |
);
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96 |
id select_type table type possible_keys key key_len ref rows Extra |
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97 |
1 PRIMARY s00 ALL NULL NULL NULL NULL 3 Using where |
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98 |
1 PRIMARY s01 ALL NULL NULL NULL NULL 3 Using join buffer |
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99 |
1 PRIMARY s02 ALL NULL NULL NULL NULL 3 Using join buffer |
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100 |
1 PRIMARY s03 ALL NULL NULL NULL NULL 3 Using join buffer |
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101 |
1 PRIMARY s04 ALL NULL NULL NULL NULL 3 Using join buffer |
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102 |
1 PRIMARY s05 ALL NULL NULL NULL NULL 3 Using join buffer |
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103 |
1 PRIMARY s06 ALL NULL NULL NULL NULL 3 Using join buffer |
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104 |
1 PRIMARY s07 ALL NULL NULL NULL NULL 3 Using join buffer |
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105 |
1 PRIMARY s08 ALL NULL NULL NULL NULL 3 Using join buffer |
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106 |
1 PRIMARY s09 ALL NULL NULL NULL NULL 3 Using join buffer |
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107 |
1 PRIMARY s10 ALL NULL NULL NULL NULL 3 Using join buffer |
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108 |
1 PRIMARY s11 ALL NULL NULL NULL NULL 3 Using join buffer |
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109 |
1 PRIMARY s12 ALL NULL NULL NULL NULL 3 Using join buffer |
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110 |
1 PRIMARY s13 ALL NULL NULL NULL NULL 3 Using join buffer |
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111 |
1 PRIMARY s14 ALL NULL NULL NULL NULL 3 Using join buffer |
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112 |
1 PRIMARY s15 ALL NULL NULL NULL NULL 3 Using join buffer |
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113 |
1 PRIMARY s16 ALL NULL NULL NULL NULL 3 Using join buffer |
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114 |
1 PRIMARY s17 ALL NULL NULL NULL NULL 3 Using join buffer |
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115 |
1 PRIMARY s18 ALL NULL NULL NULL NULL 3 Using join buffer |
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116 |
1 PRIMARY s19 ALL NULL NULL NULL NULL 3 Using join buffer |
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117 |
1 PRIMARY s20 ALL NULL NULL NULL NULL 3 Using join buffer |
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118 |
1 PRIMARY s21 ALL NULL NULL NULL NULL 3 Using join buffer |
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119 |
1 PRIMARY s22 ALL NULL NULL NULL NULL 3 Using join buffer |
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120 |
1 PRIMARY s23 ALL NULL NULL NULL NULL 3 Using join buffer |
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121 |
1 PRIMARY s24 ALL NULL NULL NULL NULL 3 Using join buffer |
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122 |
1 PRIMARY s25 ALL NULL NULL NULL NULL 3 Using join buffer |
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123 |
1 PRIMARY s26 ALL NULL NULL NULL NULL 3 Using join buffer |
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124 |
1 PRIMARY s27 ALL NULL NULL NULL NULL 3 Using join buffer |
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125 |
1 PRIMARY s28 ALL NULL NULL NULL NULL 3 Using join buffer |
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126 |
1 PRIMARY s29 ALL NULL NULL NULL NULL 3 Using join buffer |
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127 |
1 PRIMARY s30 ALL NULL NULL NULL NULL 3 Using join buffer |
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128 |
1 PRIMARY s31 ALL NULL NULL NULL NULL 3 Using join buffer |
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129 |
1 PRIMARY s32 ALL NULL NULL NULL NULL 3 Using join buffer |
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130 |
1 PRIMARY s33 ALL NULL NULL NULL NULL 3 Using join buffer |
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131 |
1 PRIMARY s34 ALL NULL NULL NULL NULL 3 Using join buffer |
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132 |
1 PRIMARY s35 ALL NULL NULL NULL NULL 3 Using join buffer |
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133 |
1 PRIMARY s36 ALL NULL NULL NULL NULL 3 Using join buffer |
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134 |
1 PRIMARY s37 ALL NULL NULL NULL NULL 3 Using join buffer |
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135 |
1 PRIMARY s38 ALL NULL NULL NULL NULL 3 Using join buffer |
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136 |
1 PRIMARY s39 ALL NULL NULL NULL NULL 3 Using join buffer |
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137 |
1 PRIMARY s40 ALL NULL NULL NULL NULL 3 Using join buffer |
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138 |
1 PRIMARY s41 ALL NULL NULL NULL NULL 3 Using join buffer |
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139 |
1 PRIMARY s42 ALL NULL NULL NULL NULL 3 Using join buffer |
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140 |
1 PRIMARY s43 ALL NULL NULL NULL NULL 3 Using join buffer |
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141 |
1 PRIMARY s44 ALL NULL NULL NULL NULL 3 Using join buffer |
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142 |
1 PRIMARY s45 ALL NULL NULL NULL NULL 3 Using join buffer |
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143 |
1 PRIMARY s46 ALL NULL NULL NULL NULL 3 Using join buffer |
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144 |
1 PRIMARY s47 ALL NULL NULL NULL NULL 3 Using join buffer |
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145 |
1 PRIMARY s48 ALL NULL NULL NULL NULL 3 Using join buffer |
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146 |
1 PRIMARY s49 ALL NULL NULL NULL NULL 3 Using join buffer |
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147 |
2 DEPENDENT SUBQUERY m00 ALL NULL NULL NULL NULL 3 Using where |
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148 |
2 DEPENDENT SUBQUERY m01 ALL NULL NULL NULL NULL 3 Using join buffer |
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149 |
2 DEPENDENT SUBQUERY m02 ALL NULL NULL NULL NULL 3 Using join buffer |
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150 |
2 DEPENDENT SUBQUERY m03 ALL NULL NULL NULL NULL 3 Using join buffer |
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151 |
2 DEPENDENT SUBQUERY m04 ALL NULL NULL NULL NULL 3 Using join buffer |
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152 |
2 DEPENDENT SUBQUERY m05 ALL NULL NULL NULL NULL 3 Using join buffer |
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153 |
2 DEPENDENT SUBQUERY m06 ALL NULL NULL NULL NULL 3 Using join buffer |
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154 |
2 DEPENDENT SUBQUERY m07 ALL NULL NULL NULL NULL 3 Using join buffer |
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155 |
2 DEPENDENT SUBQUERY m08 ALL NULL NULL NULL NULL 3 Using join buffer |
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156 |
2 DEPENDENT SUBQUERY m09 ALL NULL NULL NULL NULL 3 Using join buffer |
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157 |
2 DEPENDENT SUBQUERY m10 ALL NULL NULL NULL NULL 3 Using join buffer |
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158 |
2 DEPENDENT SUBQUERY m11 ALL NULL NULL NULL NULL 3 Using join buffer |
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159 |
2 DEPENDENT SUBQUERY m12 ALL NULL NULL NULL NULL 3 Using join buffer |
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160 |
2 DEPENDENT SUBQUERY m13 ALL NULL NULL NULL NULL 3 Using join buffer |
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161 |
2 DEPENDENT SUBQUERY m14 ALL NULL NULL NULL NULL 3 Using join buffer |
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162 |
2 DEPENDENT SUBQUERY m15 ALL NULL NULL NULL NULL 3 Using join buffer |
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163 |
2 DEPENDENT SUBQUERY m16 ALL NULL NULL NULL NULL 3 Using join buffer |
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164 |
2 DEPENDENT SUBQUERY m17 ALL NULL NULL NULL NULL 3 Using join buffer |
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165 |
2 DEPENDENT SUBQUERY m18 ALL NULL NULL NULL NULL 3 Using join buffer |
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166 |
2 DEPENDENT SUBQUERY m19 ALL NULL NULL NULL NULL 3 Using where; Using join buffer |
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167 |
select * from |
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168 |
t1 left join t2 on (t2.a= t1.a and t2.a in (select pk from t10)) |
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169 |
where t1.a < 5; |
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170 |
a b a b |
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171 |
0 0 0 0 |
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172 |
1 1 1 1 |
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173 |
2 2 2 2 |
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174 |
prepare s1 from |
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175 |
' select * from
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176 |
t1 left join t2 on (t2.a= t1.a and t2.a in (select pk from t10)) |
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177 |
where t1.a < 5'; |
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178 |
execute s1; |
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179 |
a b a b |
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180 |
0 0 0 0 |
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181 |
1 1 1 1 |
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182 |
2 2 2 2 |
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183 |
execute s1; |
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184 |
a b a b |
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185 |
0 0 0 0 |
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186 |
1 1 1 1 |
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187 |
2 2 2 2 |
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188 |
insert into t1 select (A.a + 10 * B.a),1 from t0 A, t0 B; |
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189 |
explain extended select * from t1 where a in (select pk from t10 where pk<3); |
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190 |
id select_type table type possible_keys key key_len ref rows filtered Extra |
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191 |
1 PRIMARY t1 ALL NULL NULL NULL NULL 103 100.00 Using where |
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192 |
1 PRIMARY t10 eq_ref PRIMARY PRIMARY 4 test.t1.a 1 100.00 Using index |
|
193 |
Warnings: |
|
194 |
Note 1003 select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from (`test`.`t10`) join `test`.`t1` where ((`test`.`t10`.`pk` = `test`.`t1`.`a`) and (`test`.`t1`.`a` < 3)) |
|
195 |
drop table t0, t1; |
|
196 |
drop table t10, t11, t12; |