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SET @start_global_value = @@global.optimizer_switch;
SELECT @start_global_value;
@start_global_value
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on
select @@global.optimizer_switch;
@@global.optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on
select @@session.optimizer_switch;
@@session.optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on
show global variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on
show session variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on
select * from information_schema.global_variables where variable_name='optimizer_switch';
VARIABLE_NAME VARIABLE_VALUE
OPTIMIZER_SWITCH index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on
select * from information_schema.session_variables where variable_name='optimizer_switch';
VARIABLE_NAME VARIABLE_VALUE
OPTIMIZER_SWITCH index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on
set global optimizer_switch=10;
set session optimizer_switch=5;
select @@global.optimizer_switch;
@@global.optimizer_switch
index_merge=off,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,engine_condition_pushdown=off,index_condition_pushdown=off,mrr=off,mrr_cost_based=off,block_nested_loop=off,batched_key_access=off,materialization=off,semijoin=off,loosescan=off,firstmatch=off,subquery_materialization_cost_based=off,use_index_extensions=off
select @@session.optimizer_switch;
@@session.optimizer_switch
index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,mrr=off,mrr_cost_based=off,block_nested_loop=off,batched_key_access=off,materialization=off,semijoin=off,loosescan=off,firstmatch=off,subquery_materialization_cost_based=off,use_index_extensions=off
set global optimizer_switch="index_merge_sort_union=on";
set session optimizer_switch="index_merge=off";
select @@global.optimizer_switch;
@@global.optimizer_switch
index_merge=off,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=off,index_condition_pushdown=off,mrr=off,mrr_cost_based=off,block_nested_loop=off,batched_key_access=off,materialization=off,semijoin=off,loosescan=off,firstmatch=off,subquery_materialization_cost_based=off,use_index_extensions=off
select @@session.optimizer_switch;
@@session.optimizer_switch
index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,mrr=off,mrr_cost_based=off,block_nested_loop=off,batched_key_access=off,materialization=off,semijoin=off,loosescan=off,firstmatch=off,subquery_materialization_cost_based=off,use_index_extensions=off
show global variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=off,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=off,index_condition_pushdown=off,mrr=off,mrr_cost_based=off,block_nested_loop=off,batched_key_access=off,materialization=off,semijoin=off,loosescan=off,firstmatch=off,subquery_materialization_cost_based=off,use_index_extensions=off
show session variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,mrr=off,mrr_cost_based=off,block_nested_loop=off,batched_key_access=off,materialization=off,semijoin=off,loosescan=off,firstmatch=off,subquery_materialization_cost_based=off,use_index_extensions=off
select * from information_schema.global_variables where variable_name='optimizer_switch';
VARIABLE_NAME VARIABLE_VALUE
OPTIMIZER_SWITCH index_merge=off,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=off,index_condition_pushdown=off,mrr=off,mrr_cost_based=off,block_nested_loop=off,batched_key_access=off,materialization=off,semijoin=off,loosescan=off,firstmatch=off,subquery_materialization_cost_based=off,use_index_extensions=off
select * from information_schema.session_variables where variable_name='optimizer_switch';
VARIABLE_NAME VARIABLE_VALUE
OPTIMIZER_SWITCH index_merge=off,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,mrr=off,mrr_cost_based=off,block_nested_loop=off,batched_key_access=off,materialization=off,semijoin=off,loosescan=off,firstmatch=off,subquery_materialization_cost_based=off,use_index_extensions=off
set session optimizer_switch="default";
select @@session.optimizer_switch;
@@session.optimizer_switch
index_merge=off,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=off,index_condition_pushdown=off,mrr=off,mrr_cost_based=off,block_nested_loop=off,batched_key_access=off,materialization=off,semijoin=off,loosescan=off,firstmatch=off,subquery_materialization_cost_based=off,use_index_extensions=off
set global optimizer_switch=1.1;
ERROR 42000: Incorrect argument type to variable 'optimizer_switch'
set global optimizer_switch=1e1;
ERROR 42000: Incorrect argument type to variable 'optimizer_switch'
set session optimizer_switch="index_merge";
ERROR 42000: Variable 'optimizer_switch' can't be set to the value of 'index_merge'
set session optimizer_switch="foobar";
ERROR 42000: Variable 'optimizer_switch' can't be set to the value of 'foobar'
#
# Bug#59894 set optimizer_switch to e or d causes invalid
# memory writes/valgrind warnings
set global optimizer_switch = 'd';
set global optimizer_switch = 'e';
ERROR 42000: Variable 'optimizer_switch' can't be set to the value of 'e'
SET @@global.optimizer_switch = @start_global_value;
SELECT @@global.optimizer_switch;
@@global.optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on
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