MySQL 8.0

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CREATE TABLE test (id INT, 
                   field_1 INT, 
                   field_2 INT, 
                   field_3 INT,
                   PRIMARY KEY (id),
                   INDEX (field_1));
WITH RECURSIVE
cte AS (
    SELECT 1 id
    UNION ALL
    SELECT id + 1 FROM cte WHERE id < 1000
)
INSERT INTO test
SELECT id, RAND() * 100, RAND() * 50, RAND() * 40
FROM cte;
EXPLAIN
SELECT COUNT(*)
FROM test t1
JOIN test t2 ON t1.field_1 = t2.field_2 + t2.field_3 + 10;


id
select_type
table
partitions
type
possible_keys
key
key_len
ref
rows
filtered
Extra


1
SIMPLE
t2
null
ALL
null
null
null
null
1
100.00
null

1
SIMPLE
t1
null
ref
field_1
field_1
5
func
1
100.00
Using where; Using index


EXPLAIN
SELECT COUNT(*)
FROM test t1
JOIN test t2 ON t2.field_2 + t2.field_3 + 10 = t1.field_1;


id
select_type
table
partitions
type
possible_keys
key
key_len
ref
rows
filtered
Extra


1
SIMPLE
t2
null
ALL
null
null
null
null
1
100.00
null

1
SIMPLE
t1
null
ref
field_1
field_1
5
func
1
100.00
Using where; Using index

id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	null	ALL	null	null	null	null	1	100.00	null
1	SIMPLE	t1	null	ref	field_1	field_1	5	func	1	100.00	Using where; Using index