mariadb/mysql-test/main/explain_json.test

#
# EXPLAIN FORMAT=JSON tests. These are tests developed for MariaDB.
#
--source include/default_optimizer_switch.inc

--disable_warnings
drop table if exists t0,t1,t2;
--enable_warnings

create table t0(a int);
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);

explain format=json select * from t0;

explain format=json select * from t0 where 1>2;

explain format=json select * from t0 where a<3;

--echo # Try a basic join
create table t1 (a int, b int, filler char(32), key(a));
insert into t1 
select 
  a.a + b.a* 10 + c.a * 100, 
  a.a + b.a* 10 + c.a * 100,
  'filler'
from t0 a, t0 b, t0 c;

explain format=json select * from t0,t1 where t1.a=t0.a;

--echo # Try range and index_merge
create table t2 (a1 int, a2 int, b1 int, b2 int, key(a1,a2), key(b1,b2)); 
insert into t2 select a,a,a,a from t1;

explain format=json select * from t2 where a1<5;

explain format=json select * from t2 where a1=1 or b1=2;
explain format=json select * from t2 where a1=1 or (b1=2 and b2=3);

explain format=json select * from t2 where (a1=1 and a2=1) or 
                                           (b1=2 and b2=1);

--echo # Try ref access on two key components

explain format=json select * from t0,t2 where t2.b1=t0.a and t2.b2=4;

drop table t1,t2;

--echo #
--echo # Try a UNION
--echo #
explain format=json select * from t0 A union     select * from t0 B;
explain format=json select * from t0 A union all select * from t0 B;

--echo #
--echo # Subqueries
--echo #
create table t1 (a int, b int);
insert into t1 select a,a from t0;
explain format=json select a, a > (select max(b) from t1 where t1.b=t0.a) from t0;

explain format=json 
select * from t0 where 
  a > (select max(b) from t1 where t1.b=t0.a) or a < 3 ;

drop table t1;

--echo #
--echo # Join buffering
--echo #
create table t1 (a int, b int);
insert into t1 select tbl1.a+10*tbl2.a, tbl1.a+10*tbl2.a from t0 tbl1, t0 tbl2;

explain format=json
select * from t1 tbl1, t1 tbl2 where tbl1.a=tbl2.a and tbl1.b < 3 and tbl2.b < 5;

drop table t1;

--echo #
--echo # Single-table UPDATE/DELETE, INSERT
--echo #
explain format=json delete from t0;
explain format=json delete from t0 where 1 > 2;

explain format=json delete from t0 where a < 3;

explain format=json update t0 set a=3 where a in (2,3,4);

explain format=json insert into t0 values (1);

create table t1 like t0;
explain format=json insert into t1 values ((select max(a) from t0));

drop table t1;

--echo #
--echo # A derived table
--echo #
create table t1 (a int, b int);
insert into t1 select a,a from t0;
explain format=json
select * from (select a, count(*) as cnt from t1 group by a) as tbl
where cnt>0;

explain format=json
select * from (select a, count(*) as cnt from t1 group by a) as tbl1, t1 as
tbl2 where cnt=tbl2.a;

--echo #
--echo # Non-merged semi-join (aka JTBM)
--echo #
explain format=json 
select * from t1 where a in (select max(a) from t1 group by b);

--echo #
--echo # Semi-join Materialization
--echo #
create table t2 like t1;
insert into t2 select * from t1;
explain format=json
select * from t1,t2 where t1.a in ( select a from t0);

--echo # 
--echo # First-Match
--echo # 
explain
select * from t2 where t2.a in ( select a from t1 where t1.b=t2.b);
explain format=json
select * from t2 where t2.a in ( select a from t1 where t1.b=t2.b);

--echo # 
--echo # Duplicate Weedout
--echo # 
set @tmp= @@optimizer_switch;
set optimizer_switch='firstmatch=off';
explain
select * from t2 where t2.a in ( select a from t1 where t1.b=t2.b);
explain format=json
select * from t2 where t2.a in ( select a from t1 where t1.b=t2.b);
set optimizer_switch=@tmp;

drop table t1,t2;

--echo #
--echo # MRR for range access (no BKA, just MRR)
--echo #
create table t1 (a int, b int, key(a));
insert into t1 select tbl1.a+10*tbl2.a, 12345 from t0 tbl1, t0 tbl2;
set @tmp= @@optimizer_switch;
set optimizer_switch='mrr=on,mrr_sort_keys=on';

explain format=json select * from t1 where a < 3;

--echo # 'Range checked for each record'
set optimizer_switch=@tmp;
explain format=json
select * from t1 tbl1, t1 tbl2 where tbl2.a < tbl1.b;

drop table t1;
drop table t0;

--echo #
--echo # MDEV-7265: "Full scan on NULL key", the join case
--echo #

CREATE TABLE t1 (a INT, KEY(a));
INSERT INTO t1 VALUES (1),(2);

CREATE TABLE t2 (b INT);
INSERT INTO t2 VALUES (3),(4);

EXPLAIN FORMAT=JSON SELECT * FROM t1 AS outer_t1 WHERE a <> ALL ( SELECT a FROM t1, t2 WHERE b <> outer_t1.a );

DROP TABLE t1,t2;

--echo #
--echo # Join's constant expression
--echo #
create table t0(a int);
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);

create table t1(a int, b int);
insert into t1 select tbl1.a+10*tbl2.a, 1234 from t0 tbl1, t0 tbl2;

explain format=json 
select * from t0 
where 
  20000 > all (select max(tbl1.a + tbl2.a)
               from t1 tbl1, t1 tbl2 where tbl1.b=tbl2.b);

drop table t1;
drop table t0;

--echo # 
--echo # MDEV-7264: Assertion `0' failed in subselect_engine::get_identifier() on EXPLAIN JSON
--echo # 
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (1),(2);

CREATE TABLE t2 (b INT);
INSERT INTO t2 VALUES (3),(4);

EXPLAIN FORMAT=JSON SELECT * FROM t1 WHERE a <> ALL ( SELECT b FROM t2 );
DROP TABLE t1, t2;

--echo #
--echo # MDEV-7927: Server crashes in in Time_and_counter_tracker::incr_loops
--echo #
CREATE TABLE t1 (i INT);
INSERT INTO t1 VALUES (1),(2);
EXPLAIN SELECT * FROM t1 WHERE 3 IN ( SELECT 4 UNION SELECT 5 );
DROP TABLE t1;


--echo #
--echo # MDEV-7860: EXPLAIN FORMAT=JSON crashes for loose scan query
--echo #

create table t2(a int);
insert into t2 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t1 (a int, b int, c int, d int, key(a,b,c));
insert into t1 select  A.a, B.a, C.a, D.a from t2 A, t2 B, t2 C, t2 D;
explain select count(distinct b) from t1 group by a;
explain format=json select count(distinct b) from t1 group by a;
--source include/analyze-format.inc
analyze format=json select count(distinct b) from t1 group by a;
drop table t1,t2;

--echo #
--echo # Try both variants of LooseScan (data/queries borrowed from group_min_max.test)
--echo #

create table t1 (
  a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(248) default ' '
);

insert into t1 (a1, a2, b, c, d) values
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
('a','a','b','e112','xy1'),('a','a','b','f112','xy2'),('a','a','b','g112','xy3'),('a','a','b','h112','xy4'),
('a','b','a','i121','xy1'),('a','b','a','j121','xy2'),('a','b','a','k121','xy3'),('a','b','a','l121','xy4'),
('a','b','b','m122','xy1'),('a','b','b','n122','xy2'),('a','b','b','o122','xy3'),('a','b','b','p122','xy4'),
('b','a','a','a211','xy1'),('b','a','a','b211','xy2'),('b','a','a','c211','xy3'),('b','a','a','d211','xy4'),
('b','a','b','e212','xy1'),('b','a','b','f212','xy2'),('b','a','b','g212','xy3'),('b','a','b','h212','xy4'),
('b','b','a','i221','xy1'),('b','b','a','j221','xy2'),('b','b','a','k221','xy3'),('b','b','a','l221','xy4'),
('b','b','b','m222','xy1'),('b','b','b','n222','xy2'),('b','b','b','o222','xy3'),('b','b','b','p222','xy4'),
('c','a','a','a311','xy1'),('c','a','a','b311','xy2'),('c','a','a','c311','xy3'),('c','a','a','d311','xy4'),
('c','a','b','e312','xy1'),('c','a','b','f312','xy2'),('c','a','b','g312','xy3'),('c','a','b','h312','xy4'),
('c','b','a','i321','xy1'),('c','b','a','j321','xy2'),('c','b','a','k321','xy3'),('c','b','a','l321','xy4'),
('c','b','b','m322','xy1'),('c','b','b','n322','xy2'),('c','b','b','o322','xy3'),('c','b','b','p322','xy4'),
('d','a','a','a411','xy1'),('d','a','a','b411','xy2'),('d','a','a','c411','xy3'),('d','a','a','d411','xy4'),
('d','a','b','e412','xy1'),('d','a','b','f412','xy2'),('d','a','b','g412','xy3'),('d','a','b','h412','xy4'),
('d','b','a','i421','xy1'),('d','b','a','j421','xy2'),('d','b','a','k421','xy3'),('d','b','a','l421','xy4'),
('d','b','b','m422','xy1'),('d','b','b','n422','xy2'),('d','b','b','o422','xy3'),('d','b','b','p422','xy4'),
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
('a','a','b','e112','xy1'),('a','a','b','f112','xy2'),('a','a','b','g112','xy3'),('a','a','b','h112','xy4'),
('a','b','a','i121','xy1'),('a','b','a','j121','xy2'),('a','b','a','k121','xy3'),('a','b','a','l121','xy4'),
('a','b','b','m122','xy1'),('a','b','b','n122','xy2'),('a','b','b','o122','xy3'),('a','b','b','p122','xy4'),
('b','a','a','a211','xy1'),('b','a','a','b211','xy2'),('b','a','a','c211','xy3'),('b','a','a','d211','xy4'),
('b','a','b','e212','xy1'),('b','a','b','f212','xy2'),('b','a','b','g212','xy3'),('b','a','b','h212','xy4'),
('b','b','a','i221','xy1'),('b','b','a','j221','xy2'),('b','b','a','k221','xy3'),('b','b','a','l221','xy4'),
('b','b','b','m222','xy1'),('b','b','b','n222','xy2'),('b','b','b','o222','xy3'),('b','b','b','p222','xy4'),
('c','a','a','a311','xy1'),('c','a','a','b311','xy2'),('c','a','a','c311','xy3'),('c','a','a','d311','xy4'),
('c','a','b','e312','xy1'),('c','a','b','f312','xy2'),('c','a','b','g312','xy3'),('c','a','b','h312','xy4'),
('c','b','a','i321','xy1'),('c','b','a','j321','xy2'),('c','b','a','k321','xy3'),('c','b','a','l321','xy4'),
('c','b','b','m322','xy1'),('c','b','b','n322','xy2'),('c','b','b','o322','xy3'),('c','b','b','p322','xy4'),
('d','a','a','a411','xy1'),('d','a','a','b411','xy2'),('d','a','a','c411','xy3'),('d','a','a','d411','xy4'),
('d','a','b','e412','xy1'),('d','a','b','f412','xy2'),('d','a','b','g412','xy3'),('d','a','b','h412','xy4'),
('d','b','a','i421','xy1'),('d','b','a','j421','xy2'),('d','b','a','k421','xy3'),('d','b','a','l421','xy4'),
('d','b','b','m422','xy1'),('d','b','b','n422','xy2'),('d','b','b','o422','xy3'),('d','b','b','p422','xy4');

create index idx_t1_0 on t1 (a1);
create index idx_t1_1 on t1 (a1,a2,b,c);
create index idx_t1_2 on t1 (a1,a2,b);
analyze table t1;

explain select count(distinct a1,a2,b) from t1 where (a2 >= 'b') and (b = 'a');
explain select count(distinct a1,a2,b,c) from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');

explain format=json select count(distinct a1,a2,b) from t1 where (a2 >= 'b') and (b = 'a');
explain format=json select count(distinct a1,a2,b,c) from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');

drop table t1;

--echo #
--echo # MDEV-8786 Wrong result for SELECT FORMAT=JSON * FROM t1 WHERE a=_latin1 0xDF
--echo #
CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET latin1);
INSERT INTO t1 VALUES ('a'),('b');
EXPLAIN FORMAT=JSON SELECT * FROM t1 WHERE a=_latin1 0xDF;
DROP TABLE t1;

--echo #
--echo # MDEV-8785 Wrong results for EXPLAIN EXTENDED...WHERE NULLIF(latin1_col, _utf8'a' COLLATE utf8_bin) IS NOT NULL
--echo #
CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET latin1);
INSERT INTO t1 VALUES ('a'),('A');
EXPLAIN FORMAT=JSON SELECT * FROM t1 WHERE NULLIF(a,_utf8'a' COLLATE utf8_bin);
DROP TABLE t1;

--echo #
--echo # MDEV-7970: EXPLAIN FORMAT=JSON does not print HAVING
--echo #
create table t0(a int);
insert into t0 values (0),(1),(2),(3);
create table t1(a int);
insert into t1 select A.a + B.a* 10 + C.a * 100 from t0 A, t0 B, t0 C;
create table t2 (
  a int, 
  b int, 
  key (a)
);
insert into t2 select A.a*1000 + B.a, A.a*1000 + B.a from t0 A, t1 B;
--echo # normal HAVING
explain format=json select a, max(b) as TOP from t2 group by a having TOP > a;
--echo # HAVING is always TRUE (not printed)
explain format=json select a, max(b) as TOP from t2 group by a having 1<>2;
--echo # HAVING is always FALSE (intercepted by message)
explain format=json select a, max(b) as TOP from t2 group by a having 1=2;
--echo # HAVING is absent
explain format=json select a, max(b) as TOP from t2 group by a;
drop table t0, t1, t2;

--echo #
--echo # MDEV-8829: Assertion `0' failed in Explain_table_access::tag_to_json
--echo #

--echo # Check ET_CONST_ROW_NOT_FOUND
create table t1 (i int) engine=myisam;
explain 
select * from t1;
explain format=json
select * from t1;
analyze format=json 
select * from t1;
drop table t1;

--echo # Check ET_IMPOSSIBLE_ON_CONDITION
create table t1 (a int);
create table t2 (pk int primary key);

insert into t1 values (1),(2);
insert into t2 values (1),(2);

explain 
select * from t1 left join t2 on t2.pk > 10 and t2.pk < 0;
explain format=json
select * from t1 left join t2 on t2.pk > 10 and t2.pk < 0;
--source include/analyze-format.inc
analyze format=json
select * from t1 left join t2 on t2.pk > 10 and t2.pk < 0;

--echo # Check ET_NOT_EXISTS:
explain
select * from t1 left join t2 on t2.pk=t1.a where  t2.pk is null;
explain format=json
select * from t1 left join t2 on t2.pk=t1.a where  t2.pk is null;
--source include/analyze-format.inc
analyze format=json
select * from t1 left join t2 on t2.pk=t1.a where  t2.pk is null;

--echo # Check ET_DISTINCT
explain
select distinct t1.a from t1 join t2 on t2.pk=t1.a;
explain format=json
select distinct t1.a from t1 join t2 on t2.pk=t1.a;
--source include/analyze-format.inc
analyze format=json
select distinct t1.a from t1 join t2 on t2.pk=t1.a;
drop table t1,t2;

--echo # Check ET_USING_INDEX_CONDITION_BKA
create table t1(a int);
insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);

create table t2(a int);
insert into t2 select A.a + B.a* 10 + C.a * 100 from t1 A, t1 B, t1 C;

create table t3(a int, b int);
insert into t3 select a,a from t1;

create table t4(a int, b int, c int, filler char(100), key (a,b));
insert into t4 select a,a,a, 'filler-data' from t2;

set @tmp_optimizer_switch=@@optimizer_switch;
set @tmp_join_cache_level=@@join_cache_level;
set optimizer_switch='mrr=on';
set join_cache_level=6;
explain
select * from t3,t4 where t3.a=t4.a and (t4.b+1 <= t3.b+1);
explain format=json
select * from t3,t4 where t3.a=t4.a and (t4.b+1 <= t3.b+1);
--source include/analyze-format.inc
analyze format=json
select * from t3,t4 where t3.a=t4.a and (t4.b+1 <= t3.b+1);
set optimizer_switch=@tmp_optimizer_switch;
set join_cache_level=@tmp_join_cache_level;

drop table t1,t2,t3,t4;

--echo #
--echo # MDEV-9652: EXPLAIN FORMAT=JSON should show outer_ref_cond
--echo #
create table t0(a int);
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t1 (a int, b int);
insert into t1 select a,a from t0;

explain format=json 
select a, (select max(a) from t1 where t0.a<5 and t1.b<t0.a) from t0;
drop table t0,t1;

--echo #
--echo # MDEV-10844: EXPLAIN FORMAT=JSON doesn't show order direction for filesort
--echo #

create table t1 (a int, b int);
insert into t1 values (1,2),(3,4),(2,3);
explain format=json select * from t1 order by a, b desc;
explain format=json select * from t1 order by a desc, b desc;
explain format=json select * from t1 order by a desc, b ;
drop table t1;