create procedure proc1(a int, b int)
BEGIN
prepare st1 from 'SELECT SQRT(POW(?,2) + POW(?,2)) AS hypotenuse';
execute st1 using @a, @b;
END //
SET @a = 3;
SET @b = 4;
call proc1(@a, @b);
hypotenuse
5
select OBJECT_INSTANCE_BEGIN, STATEMENT_ID, STATEMENT_NAME,
OWNER_THREAD_ID, OWNER_EVENT_ID,
OWNER_OBJECT_TYPE, OWNER_OBJECT_SCHEMA, OWNER_OBJECT_NAME
from performance_schema.prepared_statements_instances
limit 1
into @oib, @stmt_id, @stmt_name, @o_tid, @o_eid,
@o_otype, @o_oschema, @o_oname;

====================================================================
Testing index for columns OBJECT_INSTANCE_BEGIN
====================================================================
############ Explain for Query ####################################
explain select SUM_ERRORS 
from performance_schema.prepared_statements_instances 
where OBJECT_INSTANCE_BEGIN = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	#	NULL	no matching row in const table
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OBJECT_INSTANCE_BEGIN > "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ALL	PRIMARY	NULL	NULL	NULL	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OBJECT_INSTANCE_BEGIN < "2";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ALL	PRIMARY	NULL	NULL	NULL	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OBJECT_INSTANCE_BEGIN = @oib;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	const	PRIMARY	PRIMARY	8	const	#	100.00	NULL
############# Explain End #########################################
flush status;
select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OBJECT_INSTANCE_BEGIN = @oib;
SUM_ERRORS
#
OK: handler_read_key incremented

====================================================================
Testing index for columns STATEMENT_ID
====================================================================
############ Explain for Query ####################################
explain select SUM_ERRORS 
from performance_schema.prepared_statements_instances 
where STATEMENT_ID = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	STATEMENT_ID	STATEMENT_ID	8	const	#	100.00	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where STATEMENT_ID > "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ALL	STATEMENT_ID	NULL	NULL	NULL	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where STATEMENT_ID < "2";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ALL	STATEMENT_ID	NULL	NULL	NULL	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where STATEMENT_ID = @stmt_id;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	STATEMENT_ID	STATEMENT_ID	8	const	#	100.00	Using where
############# Explain End #########################################
flush status;
select SUM_ERRORS
from performance_schema.prepared_statements_instances
where STATEMENT_ID = @stmt_id;
SUM_ERRORS
#
OK: handler_read_key incremented

====================================================================
Testing index for columns STATEMENT_NAME
====================================================================
############ Explain for Query ####################################
explain select SUM_ERRORS 
from performance_schema.prepared_statements_instances 
where STATEMENT_NAME = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	STATEMENT_NAME	STATEMENT_NAME	259	const	#	100.00	NULL
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where STATEMENT_NAME > "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ALL	STATEMENT_NAME	NULL	NULL	NULL	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where STATEMENT_NAME < "2";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ALL	STATEMENT_NAME	NULL	NULL	NULL	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where STATEMENT_NAME = @stmt_name;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	STATEMENT_NAME	STATEMENT_NAME	259	const	#	100.00	NULL
############# Explain End #########################################
flush status;
select SUM_ERRORS
from performance_schema.prepared_statements_instances
where STATEMENT_NAME = @stmt_name;
SUM_ERRORS
#
OK: handler_read_key incremented

====================================================================
Testing index for columns OWNER_THREAD_ID, OWNER_EVENT_ID
====================================================================
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_THREAD_ID = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_THREAD_ID	OWNER_THREAD_ID	8	const	#	100.00	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_THREAD_ID > "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ALL	OWNER_THREAD_ID	NULL	NULL	NULL	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_THREAD_ID < "2";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ALL	OWNER_THREAD_ID	NULL	NULL	NULL	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_THREAD_ID = @o_tid;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_THREAD_ID	OWNER_THREAD_ID	8	const	#	100.00	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_THREAD_ID = "impossible"
    and OWNER_EVENT_ID = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	#	NULL	no matching row in const table
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_THREAD_ID = @o_tid
and OWNER_EVENT_ID = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	#	NULL	no matching row in const table
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_THREAD_ID = @o_tid
and OWNER_EVENT_ID > "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_THREAD_ID	OWNER_THREAD_ID	8	const	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_THREAD_ID = @o_tid
and OWNER_EVENT_ID < "2";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_THREAD_ID	OWNER_THREAD_ID	8	const	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_THREAD_ID = @o_tid
and OWNER_EVENT_ID = @o_eid;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	const	OWNER_THREAD_ID	OWNER_THREAD_ID	16	const,const	#	100.00	NULL
############# Explain End #########################################
flush status;
select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_THREAD_ID = @o_tid
and OWNER_EVENT_ID = @o_eid;
SUM_ERRORS
#
OK: handler_read_key incremented

====================================================================
Testing index for columns OWNER_OBJECT_TYPE, OWNER_OBJECT_SCHEMA, OWNER_OBJECT_NAME
====================================================================
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	2	const	#	100.00	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE > "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ALL	OWNER_OBJECT_TYPE	NULL	NULL	NULL	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE < "2";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ALL	OWNER_OBJECT_TYPE	NULL	NULL	NULL	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = @o_otype;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	2	const	#	100.00	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = "impossible"
    and OWNER_OBJECT_SCHEMA = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	261	const,const	#	100.00	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = @o_otype
and OWNER_OBJECT_SCHEMA = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	261	const,const	#	100.00	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = @o_otype
and OWNER_OBJECT_SCHEMA > "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	2	const	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = @o_otype
and OWNER_OBJECT_SCHEMA < "2";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	2	const	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = @o_otype
and OWNER_OBJECT_SCHEMA = @o_oschema;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	261	const,const	#	100.00	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = "impossible"
    and OWNER_OBJECT_SCHEMA = "impossible"
    and OWNER_OBJECT_NAME = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	520	const,const,const	#	100.00	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = @o_otype
and OWNER_OBJECT_SCHEMA = @o_oschema
and OWNER_OBJECT_NAME = "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	520	const,const,const	#	100.00	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = @o_otype
and OWNER_OBJECT_SCHEMA = @o_oschema
and OWNER_OBJECT_NAME > "impossible";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	261	const,const	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = @o_otype
and OWNER_OBJECT_SCHEMA = @o_oschema
and OWNER_OBJECT_NAME < "2";
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	261	const,const	#	33.33	Using where
############ Explain for Query ####################################
explain select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = @o_otype
and OWNER_OBJECT_SCHEMA = @o_oschema
and OWNER_OBJECT_NAME = @o_oname;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	prepared_statements_instances	NULL	ref	OWNER_OBJECT_TYPE	OWNER_OBJECT_TYPE	520	const,const,const	#	100.00	Using where
############# Explain End #########################################
flush status;
select SUM_ERRORS
from performance_schema.prepared_statements_instances
where OWNER_OBJECT_TYPE = @o_otype
and OWNER_OBJECT_SCHEMA = @o_oschema
and OWNER_OBJECT_NAME = @o_oname;
SUM_ERRORS
#
OK: handler_read_key incremented
deallocate prepare st1;
drop procedure proc1;