@@ -310,9 +310,10 @@ t2.Code IN (SELECT Country FROM t3
WHERE Language='English' AND Percentage > 10 AND
t2.Population > 100000);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 range Population,Country Population 4 NULL 1 Using index condition; Rowid-ordered scan
1 PRIMARY t3 eq_ref PRIMARY,Percentage PRIMARY 33 test.t1.Country,const 1 Using index condition; Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1 PRIMARY t2 eq_ref PRIMARY,Population PRIMARY 3 test.t1.Country 1 Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
1 PRIMARY subselect2 ALL unique_key NULL NULL NULL 1
1 PRIMARY t2 eq_ref PRIMARY,Population PRIMARY 3 test.t1.Country 1 Using where; Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
1 PRIMARY t3 eq_ref PRIMARY,Percentage PRIMARY 33 test.t1.Country,const 1 Using index condition; Using where; Using join buffer (incremental, BKA join); Key-ordered Rowid-ordered scan
2 SUBQUERY t1 range Population,Country Population 4 NULL 1 Using index condition; Rowid-ordered scan