Files
percona-toolkit/t/pt-visual-explain/samples/full_scan_on_null_key.sql
2011-06-24 16:02:05 -06:00

9 lines
421 B
SQL

EXPLAIN
SELECT * FROM t1
WHERE t1.id NOT IN (SELECT t2.id FROM t2,t3
WHERE t3.name='xxx' AND t2.id=t3.id);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 4 Using where
2 DEPENDENT SUBQUERY t2 eq_ref PRIMARY PRIMARY 4 func 1 Using where; Using index; Full scan on NULL key
2 DEPENDENT SUBQUERY t3 eq_ref PRIMARY PRIMARY 4 func 1 Using where; Full scan on NULL key