drop table if exists t;
create table t (v int);
explain format = 'brief' select * from t t1, t t2;
id	estRows	task	access object	operator info
HashJoin	100000000.00	root		CARTESIAN inner join
├─TableReader(Build)	10000.00	root		data:TableFullScan
│ └─TableFullScan	10000.00	cop[tikv]	table:t2	keep order:false, stats:pseudo
└─TableReader(Probe)	10000.00	root		data:TableFullScan
  └─TableFullScan	10000.00	cop[tikv]	table:t1	keep order:false, stats:pseudo
explain format = 'brief' select * from t t1 where exists (select 1 from t t2 where t2.v > t1.v);
id	estRows	task	access object	operator info
HashJoin	7992.00	root		CARTESIAN semi join, other cond:gt(executor__explain.t.v, executor__explain.t.v)
├─TableReader(Build)	9990.00	root		data:Selection
│ └─Selection	9990.00	cop[tikv]		not(isnull(executor__explain.t.v))
│   └─TableFullScan	10000.00	cop[tikv]	table:t2	keep order:false, stats:pseudo
└─TableReader(Probe)	9990.00	root		data:Selection
  └─Selection	9990.00	cop[tikv]		not(isnull(executor__explain.t.v))
    └─TableFullScan	10000.00	cop[tikv]	table:t1	keep order:false, stats:pseudo
explain format = 'brief' select * from t t1 where exists (select 1 from t t2 where t2.v in (t1.v+1, t1.v+2));
id	estRows	task	access object	operator info
HashJoin	8000.00	root		CARTESIAN semi join, other cond:in(executor__explain.t.v, plus(executor__explain.t.v, 1), plus(executor__explain.t.v, 2))
├─TableReader(Build)	10000.00	root		data:TableFullScan
│ └─TableFullScan	10000.00	cop[tikv]	table:t2	keep order:false, stats:pseudo
└─TableReader(Probe)	10000.00	root		data:TableFullScan
  └─TableFullScan	10000.00	cop[tikv]	table:t1	keep order:false, stats:pseudo
explain format = 'brief' select * from t t1, t t2 where t1.v = t2.v;
id	estRows	task	access object	operator info
HashJoin	12487.50	root		inner join, equal:[eq(executor__explain.t.v, executor__explain.t.v)]
├─TableReader(Build)	9990.00	root		data:Selection
│ └─Selection	9990.00	cop[tikv]		not(isnull(executor__explain.t.v))
│   └─TableFullScan	10000.00	cop[tikv]	table:t2	keep order:false, stats:pseudo
└─TableReader(Probe)	9990.00	root		data:Selection
  └─Selection	9990.00	cop[tikv]		not(isnull(executor__explain.t.v))
    └─TableFullScan	10000.00	cop[tikv]	table:t1	keep order:false, stats:pseudo
drop table if exists t;
create table t (a int);
explain analyze insert into t select 1;
select * from t;
a
1
explain analyze update t set a=2 where a=1;
select * from t;
a
2
explain format = 'brief' insert into t select 1;
select * from t;
a
2
explain analyze insert into t select 1;
explain analyze replace into t values (3);
select * from t order by a;
a
1
2
3
desc format='brief' select * from information_schema.statements_summary;
id	estRows	task	access object	operator info
MemTableScan	10000.00	root	table:STATEMENTS_SUMMARY	
desc format='brief' select * from information_schema.statements_summary where digest is null;
id	estRows	task	access object	operator info
Selection	8000.00	root		isnull(Column#5)
└─MemTableScan	10000.00	root	table:STATEMENTS_SUMMARY	
desc format='brief' select * from information_schema.statements_summary where digest = 'abcdefg';
id	estRows	task	access object	operator info
MemTableScan	10000.00	root	table:STATEMENTS_SUMMARY	digests: ["abcdefg"]
desc format='brief' select * from information_schema.statements_summary where digest in ('a','b','c');
id	estRows	task	access object	operator info
MemTableScan	10000.00	root	table:STATEMENTS_SUMMARY	digests: ["a","b","c"]
drop table if exists tt123;
CREATE TABLE tt123 (
id int(11) NOT NULL,
a bigint(20) DEFAULT NULL,
b char(20) DEFAULT NULL,
c datetime DEFAULT NULL,
d double DEFAULT NULL,
e json DEFAULT NULL,
f decimal(40,6) DEFAULT NULL,
PRIMARY KEY (id) /*T![clustered_index] CLUSTERED */,
KEY a (a),
KEY b (b),
KEY c (c),
KEY d (d),
KEY f (f)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;
explain format='brief' select /*+ inl_hash_join(t1) */ * from tt123 t1 join tt123 t2 on t1.b=t2.e;
id	estRows	task	access object	operator info
Projection	12500.00	root		executor__explain.tt123.id, executor__explain.tt123.a, executor__explain.tt123.b, executor__explain.tt123.c, executor__explain.tt123.d, executor__explain.tt123.e, executor__explain.tt123.f, executor__explain.tt123.id, executor__explain.tt123.a, executor__explain.tt123.b, executor__explain.tt123.c, executor__explain.tt123.d, executor__explain.tt123.e, executor__explain.tt123.f
└─HashJoin	12500.00	root		inner join, equal:[eq(executor__explain.tt123.e, Column#15)]
  ├─TableReader(Build)	10000.00	root		data:TableFullScan
  │ └─TableFullScan	10000.00	cop[tikv]	table:t2	keep order:false, stats:pseudo
  └─Projection(Probe)	10000.00	root		executor__explain.tt123.id, executor__explain.tt123.a, executor__explain.tt123.b, executor__explain.tt123.c, executor__explain.tt123.d, executor__explain.tt123.e, executor__explain.tt123.f, cast(executor__explain.tt123.b, json BINARY)->Column#15
    └─TableReader	10000.00	root		data:TableFullScan
      └─TableFullScan	10000.00	cop[tikv]	table:t1	keep order:false, stats:pseudo
drop table if exists t;
create table t (a int primary key);
insert into t values (2);
set @@tidb_constraint_check_in_place=1;
explain analyze insert into t values (1), (2), (3);
Error 1062 (23000): Duplicate entry '2' for key 't.PRIMARY'
select * from t;
a
2
set @@tidb_constraint_check_in_place=DEFAULT;
drop table if exists t;
create table t(a int);
set @@session.tidb_enable_non_prepared_plan_cache = 1;
select * from t limit 1;
a
select * from t limit 1;
a
explain format = 'plan_cache' select * from (select * from t) t1 limit 1;
id	estRows	task	access object	operator info
Limit_8	1.00	root		offset:0, count:1
└─TableReader_12	1.00	root		data:Limit_11
  └─Limit_11	1.00	cop[tikv]		offset:0, count:1
    └─TableFullScan_10	1.00	cop[tikv]	table:t	keep order:false, stats:pseudo
show warnings;
Level	Code	Message
Warning	1105	skip non-prepared plan-cache: queries that have sub-queries are not supported
explain format = 'plan_cache' select * from (select * from t) t1 limit 1;
id	estRows	task	access object	operator info
Limit_8	1.00	root		offset:0, count:1
└─TableReader_12	1.00	root		data:Limit_11
  └─Limit_11	1.00	cop[tikv]		offset:0, count:1
    └─TableFullScan_10	1.00	cop[tikv]	table:t	keep order:false, stats:pseudo
select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain analyze format = 'plan_cache' select * from (select * from t) t1 limit 1;
show warnings;
Level	Code	Message
Warning	1105	skip non-prepared plan-cache: queries that have sub-queries are not supported
explain analyze format = 'plan_cache' select * from (select * from t) t1 limit 1;
select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain format = 'plan_cache' select * from t;
id	estRows	task	access object	operator info
TableReader_5	10000.00	root		data:TableFullScan_4
└─TableFullScan_4	10000.00	cop[tikv]	table:t	keep order:false, stats:pseudo
show warnings;
Level	Code	Message
explain format = 'plan_cache' select * from t;
id	estRows	task	access object	operator info
TableReader_5	10000.00	root		data:TableFullScan_4
└─TableFullScan_4	10000.00	cop[tikv]	table:t	keep order:false, stats:pseudo
select @@last_plan_from_cache;
@@last_plan_from_cache
1
explain analyze format = 'plan_cache' select * from t;
show warnings;
Level	Code	Message
explain analyze format = 'plan_cache' select * from t;
select @@last_plan_from_cache;
@@last_plan_from_cache
1
explain select * from t;
id	estRows	task	access object	operator info
TableReader_5	10000.00	root		data:TableFullScan_4
└─TableFullScan_4	10000.00	cop[tikv]	table:t	keep order:false, stats:pseudo
select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain format = 'brief' select * from t;
id	estRows	task	access object	operator info
TableReader	10000.00	root		data:TableFullScan
└─TableFullScan	10000.00	cop[tikv]	table:t	keep order:false, stats:pseudo
select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain format = 'dot' select * from t;
dot contents

digraph TableReader_5 {
subgraph cluster5{
node [style=filled, color=lightgrey]
color=black
label = "root"
"TableReader_5"
}
subgraph cluster4{
node [style=filled, color=lightgrey]
color=black
label = "cop"
"TableFullScan_4"
}
"TableReader_5" -> "TableFullScan_4"
}

select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain format = 'hint' select * from t;
hint
use_index(@`sel_1` `executor__explain`.`t` )
select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain format = 'row' select * from t;
id	estRows	task	access object	operator info
TableReader_5	10000.00	root		data:TableFullScan_4
└─TableFullScan_4	10000.00	cop[tikv]	table:t	keep order:false, stats:pseudo
select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain format = 'verbose' select * from t;
id	estRows	estCost	task	access object	operator info
TableReader_5	10000.00	177906.67	root		data:TableFullScan_4
└─TableFullScan_4	10000.00	2035000.00	cop[tikv]	table:t	keep order:false, stats:pseudo
select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain format = 'traditional' select * from t;
id	estRows	task	access object	operator info
TableReader_5	10000.00	root		data:TableFullScan_4
└─TableFullScan_4	10000.00	cop[tikv]	table:t	keep order:false, stats:pseudo
select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain format = 'binary' select * from t;
binary plan
zQFYCsoBCg1UYWJsZVJlYWRlcl81EncKD1QBEVBGdWxsU2Nhbl80IQEAAAA4DT9BKQABAfBGiMNAOAJAAkoYChYKEWV4ZWN1dG9yX19leHBsYWluEgF0Uh5rZWVwIG9yZGVyOmZhbHNlLCBzdGF0czpwc2V1ZG9w//////8BAwQBeAEGBQEgASFVVVVVlbcFHWYoAUABUhRkYXRhOlQ2kgAAcAUzAQEsAXj///////////8B
select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain format = 'tidb_json' select * from t;
TiDB_JSON
[
    {
        "id": "TableReader_5",
        "estRows": "10000.00",
        "taskType": "root",
        "operatorInfo": "data:TableFullScan_4",
        "subOperators": [
            {
                "id": "TableFullScan_4",
                "estRows": "10000.00",
                "taskType": "cop[tikv]",
                "accessObject": "table:t",
                "operatorInfo": "keep order:false, stats:pseudo"
            }
        ]
    }
]

select @@last_plan_from_cache;
@@last_plan_from_cache
0
explain format = 'cost_trace' select * from t;
id	estRows	estCost	costFormula	task	access object	operator info
TableReader_5	10000.00	177906.67	((scan(10000*logrowsize(32)*tikv_scan_factor(40.7))) + (net(10000*rowsize(16)*tidb_kv_net_factor(3.96))))/15.00	root		data:TableFullScan_4
└─TableFullScan_4	10000.00	2035000.00	scan(10000*logrowsize(32)*tikv_scan_factor(40.7))	cop[tikv]	table:t	keep order:false, stats:pseudo
select @@last_plan_from_cache;
@@last_plan_from_cache
0
set @@session.tidb_enable_non_prepared_plan_cache = DEFAULT;
drop table if exists t;
drop view if exists v;
drop user if exists 'explain'@'%';
create table t (id int);
create view v as select * from t;
create user 'explain'@'%';
grant select on executor__explain.v to 'explain'@'%';
show databases;
Database
INFORMATION_SCHEMA
executor__explain
use executor__explain;
select * from v;
id
explain format = 'brief' select * from v;
Error 1345 (HY000): EXPLAIN/SHOW can not be issued; lacking privileges for underlying table
grant show view on executor__explain.v to 'explain'@'%';
explain format = 'brief' select * from v;
id	estRows	task	access object	operator info
TableReader	10000.00	root		data:TableFullScan
└─TableFullScan	10000.00	cop[tikv]	table:t	keep order:false, stats:pseudo
revoke select on executor__explain.v from 'explain'@'%';
explain format = 'brief' select * from v;
Error 1142 (42000): SELECT command denied to user 'explain'@'%' for table 'v'
create table t1 (i int);
create table t2 (j int);
create table t3 (k int, secret int);
create view v1 as select * from t1;
create view v2 as select * from v1, t2;
create view v3 as select k from t3;
grant select, show view on executor__explain.v2 to 'explain'@'%';
grant         show view on executor__explain.v1 to 'explain'@'%';
grant select, show view on executor__explain.t3 to 'explain'@'%';
grant select, show view on executor__explain.v3 to 'explain'@'%';
explain select * from v1;
Error 1142 (42000): SELECT command denied to user 'explain'@'%' for table 'v1'
explain select * from v2;
Error 1345 (HY000): EXPLAIN/SHOW can not be issued; lacking privileges for underlying table
explain select * from t3;
id	estRows	task	access object	operator info
TableReader_5	10000.00	root		data:TableFullScan_4
└─TableFullScan_4	10000.00	cop[tikv]	table:t3	keep order:false, stats:pseudo
explain select * from v3;
id	estRows	task	access object	operator info
TableReader_7	10000.00	root		data:TableFullScan_6
└─TableFullScan_6	10000.00	cop[tikv]	table:t3	keep order:false, stats:pseudo
drop table if exists t1;
create table t1(
id1 varchar(2) DEFAULT '00',
id2 varchar(30) NOT NULL,
id3 datetime DEFAULT NULL,
id4 varchar(100) NOT NULL DEFAULT 'ecifdata',
id5 datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
id6 int(11) DEFAULT NULL,
id7 int(11) DEFAULT NULL,
UNIQUE KEY UI_id2 (id2),
KEY ix_id1 (id1)
);
drop table if exists t2;
create table t2(
id10 varchar(40) NOT NULL,
id2 varchar(30) NOT NULL,
KEY IX_id2 (id2),
PRIMARY KEY (id10)
);
drop table if exists t3;
create table t3(
id20 varchar(40) DEFAULT NULL,
UNIQUE KEY IX_id20 (id20)
);
explain UPDATE t1 a
SET a.id1 = '04',
a.id3 = CURRENT_TIMESTAMP,
a.id4 = SUBSTRING_INDEX(USER(), '@', 1),
a.id5 = CURRENT_TIMESTAMP
WHERE a.id1 = '03'
AND a.id6 - IFNULL(a.id7, 0) =
(
SELECT COUNT(1)
FROM t2 b, t3 c
WHERE b.id10 = c.id20
AND b.id2 = a.id2
AND b.id2 in (
SELECT rn.id2
FROM t1 rn
WHERE rn.id1 = '03'
)
);
id	estRows	task	access object	operator info
Update_17	N/A	root		N/A
└─Projection_28	8.00	root		executor__explain.t1.id1, executor__explain.t1.id2, executor__explain.t1.id3, executor__explain.t1.id4, executor__explain.t1.id5, executor__explain.t1.id6, executor__explain.t1.id7, executor__explain.t1._tidb_rowid
  └─Selection_29	8.00	root		eq(minus(executor__explain.t1.id6, ifnull(executor__explain.t1.id7, 0)), ifnull(Column#22, 0))
    └─HashJoin_32	10.00	root		left outer join, equal:[eq(executor__explain.t1.id2, executor__explain.t2.id2)]
      ├─HashAgg_69(Build)	12.50	root		group by:executor__explain.t2.id2, funcs:count(1)->Column#22, funcs:firstrow(executor__explain.t2.id2)->executor__explain.t2.id2
      │ └─IndexJoin_76	15.62	root		inner join, inner:IndexReader_75, outer key:executor__explain.t2.id10, inner key:executor__explain.t3.id20, equal cond:eq(executor__explain.t2.id10, executor__explain.t3.id20)
      │   ├─IndexHashJoin_93(Build)	12.50	root		inner join, inner:IndexLookUp_90, outer key:executor__explain.t1.id2, inner key:executor__explain.t2.id2, equal cond:eq(executor__explain.t1.id2, executor__explain.t2.id2)
      │   │ ├─Projection_103(Build)	10.00	root		executor__explain.t1.id2
      │   │ │ └─IndexLookUp_109	10.00	root		
      │   │ │   ├─IndexRangeScan_107(Build)	10.00	cop[tikv]	table:rn, index:ix_id1(id1)	range:["03","03"], keep order:false, stats:pseudo
      │   │ │   └─TableRowIDScan_108(Probe)	10.00	cop[tikv]	table:rn	keep order:false, stats:pseudo
      │   │ └─IndexLookUp_90(Probe)	12.50	root		
      │   │   ├─IndexRangeScan_88(Build)	12.50	cop[tikv]	table:b, index:IX_id2(id2)	range: decided by [eq(executor__explain.t2.id2, executor__explain.t1.id2)], keep order:false, stats:pseudo
      │   │   └─TableRowIDScan_89(Probe)	12.50	cop[tikv]	table:b	keep order:false, stats:pseudo
      │   └─IndexReader_75(Probe)	12.50	root		index:Selection_74
      │     └─Selection_74	12.50	cop[tikv]		not(isnull(executor__explain.t3.id20))
      │       └─IndexRangeScan_73	12.50	cop[tikv]	table:c, index:IX_id20(id20)	range: decided by [eq(executor__explain.t3.id20, executor__explain.t2.id10)], keep order:false, stats:pseudo
      └─IndexLookUp_68(Probe)	10.00	root		
        ├─IndexRangeScan_66(Build)	10.00	cop[tikv]	table:a, index:ix_id1(id1)	range:["03","03"], keep order:false, stats:pseudo
        └─TableRowIDScan_67(Probe)	10.00	cop[tikv]	table:a	keep order:false, stats:pseudo
drop table if exists t;
create table t (a int, b int, index (a));
insert into t values (1, 1);
explain analyze select * from t t1, t t2 where t1.b = t2.a and t1.b = 2333;
id	estRows	actRows	task	access object	execution info	operator info	memory	disk
HashJoin_8	100.00	0	root		<execution_info>	CARTESIAN inner join	<memory>	<disk>
├─IndexLookUp_18(Build)	10.00	0	root		<execution_info>		<memory>	<disk>
│ ├─IndexRangeScan_16(Build)	10.00	0	cop[tikv]	table:t2, index:a(a)	<execution_info>	range:[2333,2333], keep order:false, stats:pseudo	<memory>	<disk>
│ └─TableRowIDScan_17(Probe)	10.00	0	cop[tikv]	table:t2	<execution_info>	keep order:false, stats:pseudo	<memory>	<disk>
└─TableReader_12(Probe)	10.00	0	root		<execution_info>	data:Selection_11	<memory>	<disk>
  └─Selection_11	10.00	0	cop[tikv]		<execution_info>	eq(executor__explain.t.b, 2333)	<memory>	<disk>
    └─TableFullScan_10	10000.00	1	cop[tikv]	table:t1	<execution_info>	keep order:false, stats:pseudo	<memory>	<disk>