This query:

SELECT *
FROM (
SELECT *
FROM t3
WHERE t3.b <= 'c'
) AS alias1
RIGHT JOIN t1
ON t1.a = alias1.b
AND ( 6 ) IN (
SELECT a
FROM t2
)

crashes when executed with derived_merge=ON, semijoin=ON and prepared statement.

explain:

id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
3 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables

optimizer switch: derived_merge=ON,semijoin=ON
full switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=off,derived_merge=on,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on

test case:

CREATE TABLE t1 ( a varchar(1)) ;

CREATE TABLE t2 ( a int(11), b int(11)) ;

CREATE TABLE t3 ( a int(11) NOT NULL , b varchar(1)) ;

SET SESSION optimizer_switch = 'derived_merge=on';
SET SESSION optimizer_switch = 'semijoin=on';

PREPARE st1 from "
SELECT *
FROM (
SELECT *
FROM t3
WHERE t3.b <= 0
) AS alias1
RIGHT JOIN t1
ON t1.a = alias1.b
AND ( 6 ) IN (
SELECT a
FROM t2
)";
EXECUTE st1;

bzr version-info
revision-id: <email address hidden>
date: 2011-10-19 21:01:42 +0200
build-date: 2011-10-20 13:09:07 +0300
revno: 3242
branch-nick: maria-5.3