~drizzle-trunk/drizzle/development

#

# 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;