1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
|
#
# A simple test of the greedy query optimization algorithm and the switches that
# control the optimizationprocess.
#
#
# Schema
#
--disable_warnings
drop table if exists t1,t2,t3,t4,t5,t6,t7;
--enable_warnings
create table t1 (
c11 integer,c12 integer,c13 integer,c14 integer,c15 integer,c16 integer,
primary key (c11)
);
create table t2 (
c21 integer,c22 integer,c23 integer,c24 integer,c25 integer,c26 integer
);
create table t3 (
c31 integer,c32 integer,c33 integer,c34 integer,c35 integer,c36 integer,
primary key (c31)
);
create table t4 (
c41 integer,c42 integer,c43 integer,c44 integer,c45 integer,c46 integer
);
create table t5 (
c51 integer,c52 integer,c53 integer,c54 integer,c55 integer,c56 integer,
primary key (c51)
);
create table t6 (
c61 integer,c62 integer,c63 integer,c64 integer,c65 integer,c66 integer
);
create table t7 (
c71 integer,c72 integer,c73 integer,c74 integer,c75 integer,c76 integer,
primary key (c71)
);
#
# Data
# cardinality(Ti) = cardinality(T(i-1)) + 3
#
insert into t1 values (1,2,3,4,5,6);
insert into t1 values (2,2,3,4,5,6);
insert into t1 values (3,2,3,4,5,6);
insert into t2 values (1,2,3,4,5,6);
insert into t2 values (2,2,3,4,5,6);
insert into t2 values (3,2,3,4,5,6);
insert into t2 values (4,2,3,4,5,6);
insert into t2 values (5,2,3,4,5,6);
insert into t2 values (6,2,3,4,5,6);
insert into t3 values (1,2,3,4,5,6);
insert into t3 values (2,2,3,4,5,6);
insert into t3 values (3,2,3,4,5,6);
insert into t3 values (4,2,3,4,5,6);
insert into t3 values (5,2,3,4,5,6);
insert into t3 values (6,2,3,4,5,6);
insert into t3 values (7,2,3,4,5,6);
insert into t3 values (8,2,3,4,5,6);
insert into t3 values (9,2,3,4,5,6);
insert into t4 values (1,2,3,4,5,6);
insert into t4 values (2,2,3,4,5,6);
insert into t4 values (3,2,3,4,5,6);
insert into t4 values (4,2,3,4,5,6);
insert into t4 values (5,2,3,4,5,6);
insert into t4 values (6,2,3,4,5,6);
insert into t4 values (7,2,3,4,5,6);
insert into t4 values (8,2,3,4,5,6);
insert into t4 values (9,2,3,4,5,6);
insert into t4 values (10,2,3,4,5,6);
insert into t4 values (11,2,3,4,5,6);
insert into t4 values (12,2,3,4,5,6);
insert into t5 values (1,2,3,4,5,6);
insert into t5 values (2,2,3,4,5,6);
insert into t5 values (3,2,3,4,5,6);
insert into t5 values (4,2,3,4,5,6);
insert into t5 values (5,2,3,4,5,6);
insert into t5 values (6,2,3,4,5,6);
insert into t5 values (7,2,3,4,5,6);
insert into t5 values (8,2,3,4,5,6);
insert into t5 values (9,2,3,4,5,6);
insert into t5 values (10,2,3,4,5,6);
insert into t5 values (11,2,3,4,5,6);
insert into t5 values (12,2,3,4,5,6);
insert into t5 values (13,2,3,4,5,6);
insert into t5 values (14,2,3,4,5,6);
insert into t5 values (15,2,3,4,5,6);
insert into t6 values (1,2,3,4,5,6);
insert into t6 values (2,2,3,4,5,6);
insert into t6 values (3,2,3,4,5,6);
insert into t6 values (4,2,3,4,5,6);
insert into t6 values (5,2,3,4,5,6);
insert into t6 values (6,2,3,4,5,6);
insert into t6 values (7,2,3,4,5,6);
insert into t6 values (8,2,3,4,5,6);
insert into t6 values (9,2,3,4,5,6);
insert into t6 values (10,2,3,4,5,6);
insert into t6 values (11,2,3,4,5,6);
insert into t6 values (12,2,3,4,5,6);
insert into t6 values (13,2,3,4,5,6);
insert into t6 values (14,2,3,4,5,6);
insert into t6 values (15,2,3,4,5,6);
insert into t6 values (16,2,3,4,5,6);
insert into t6 values (17,2,3,4,5,6);
insert into t6 values (18,2,3,4,5,6);
insert into t7 values (1,2,3,4,5,6);
insert into t7 values (2,2,3,4,5,6);
insert into t7 values (3,2,3,4,5,6);
insert into t7 values (4,2,3,4,5,6);
insert into t7 values (5,2,3,4,5,6);
insert into t7 values (6,2,3,4,5,6);
insert into t7 values (7,2,3,4,5,6);
insert into t7 values (8,2,3,4,5,6);
insert into t7 values (9,2,3,4,5,6);
insert into t7 values (10,2,3,4,5,6);
insert into t7 values (11,2,3,4,5,6);
insert into t7 values (12,2,3,4,5,6);
insert into t7 values (13,2,3,4,5,6);
insert into t7 values (14,2,3,4,5,6);
insert into t7 values (15,2,3,4,5,6);
insert into t7 values (16,2,3,4,5,6);
insert into t7 values (17,2,3,4,5,6);
insert into t7 values (18,2,3,4,5,6);
insert into t7 values (19,2,3,4,5,6);
insert into t7 values (20,2,3,4,5,6);
insert into t7 values (21,2,3,4,5,6);
#
# The actual test begins here
#
# Check the default values for the optimizer paramters
select @@optimizer_search_depth;
select @@optimizer_prune_level;
# This value swithes back to the old implementation of 'find_best()'
# set optimizer_search_depth=63; - old (independent of the optimizer_prune_level)
#
# These are the values for the parameters that control the greedy optimizer
# (total 6 combinations - 3 for optimizer_search_depth, 2 for optimizer_prune_level):
# 3:
# set optimizer_search_depth=0; - automatic
# set optimizer_search_depth=1; - min
# set optimizer_search_depth=62; - max (default)
# 2:
# set optimizer_prune_level=0 - exhaustive;
# set optimizer_prune_level=1 - heuristic; # default
#
# Compile several queries with all combinations of the query
# optimizer parameters. Each test query has two variants, where
# in the second variant the tables in the FROM clause are in
# inverse order to the tables in the first variant.
# Due to pre-sorting of tables before compilation, there should
# be no difference in the plans for each two such query variants.
#
# First, for reference compile the test queries with the 'old' optimization
# procedure 'find_best'. Notice that 'find_best' does not depend on the
# choice of heuristic.
set optimizer_search_depth=63;
select @@optimizer_search_depth;
# 6-table join, chain
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, star
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, clique
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
# Test the new optimization procedures
set optimizer_prune_level=0;
select @@optimizer_prune_level;
set optimizer_search_depth=0;
select @@optimizer_search_depth;
# 6-table join, chain
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, star
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, clique
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
set optimizer_search_depth=1;
select @@optimizer_search_depth;
# 6-table join, chain
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, star
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, clique
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
set optimizer_search_depth=62;
select @@optimizer_search_depth;
# 6-table join, chain
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, star
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, clique
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
set optimizer_prune_level=1;
select @@optimizer_prune_level;
set optimizer_search_depth=0;
select @@optimizer_search_depth;
# 6-table join, chain
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, star
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, clique
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
set optimizer_search_depth=1;
select @@optimizer_search_depth;
# 6-table join, chain
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, star
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, clique
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
set optimizer_search_depth=62;
select @@optimizer_search_depth;
# 6-table join, chain
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, star
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
show status like 'Last_query_cost';
# 6-table join, clique
explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
show status like 'Last_query_cost';
drop table t1,t2,t3,t4,t5,t6,t7;
|