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| Current File : //home/usr.opt/mysql57/mysql-test/r/explain_other.result |
# WL#6369: EXPLAIN for other query
CREATE DATABASE mysqltest1;
USE mysqltest1;
CREATE TABLE t1 (f1 int);
INSERT INTO t1 VALUES (1),(2);
ERROR HY000: This command is not supported in the prepared statement protocol yet
Test error throwing
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'EXPLAIN SELECT f1 FROM t1'
ERROR HY000: EXPLAIN FOR CONNECTION command is supported only for SELECT/UPDATE/INSERT/DELETE/REPLACE
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SHOW FIELDS IN t1'
ERROR HY000: EXPLAIN FOR CONNECTION command is supported only for SELECT/UPDATE/INSERT/DELETE/REPLACE
PREPARE stmt FROM 'EXPLAIN FOR CONNECTION 1';
ERROR HY000: This command is not supported in the prepared statement protocol yet
PREPARE stmt FROM 'SELECT * FROM t1';
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'EXECUTE stmt'
ERROR HY000: EXPLAIN FOR CONNECTION command is supported only for SELECT/UPDATE/INSERT/DELETE/REPLACE
CREATE PROCEDURE proc6369()
EXPLAIN FOR CONNECTION 1;
ERROR 42000: This version of MySQL doesn't yet support 'non-standalone EXPLAIN FOR CONNECTION'
CREATE PROCEDURE proc6369()
SELECT * FROM t1;
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'CALL proc6369()'
ERROR HY000: EXPLAIN FOR CONNECTION command is supported only for SELECT/UPDATE/INSERT/DELETE/REPLACE
DROP PROCEDURE proc6369;
ERROR HY000: EXPLAIN FOR CONNECTION command is supported only for SELECT/UPDATE/INSERT/DELETE/REPLACE
EXPLAIN FOR CONNECTION 11111111;
ERROR HY000: Unknown thread id: 11111111
Explain queries with ready plan
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT f1 FROM t1'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 NULL ALL NULL NULL NULL NULL 2 100.00 NULL
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT * FROM (SELECT * FROM t1) tt'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 NULL ALL NULL NULL NULL NULL 2 100.00 NULL
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT * FROM t1 WHERE f1 IN (SELECT * FROM t1)'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 NULL ALL NULL NULL NULL NULL 2 100.00 NULL
1 SIMPLE t1 NULL ALL NULL NULL NULL NULL 2 50.00 Using where; FirstMatch(t1); Using join buffer (Block Nested Loop)
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT * FROM t1 UNION ALL SELECT * FROM t1 ORDER BY 1'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 NULL ALL NULL NULL NULL NULL 2 100.00 NULL
2 UNION t1 NULL ALL NULL NULL NULL NULL 2 100.00 NULL
NULL UNION RESULT <union1,2> NULL ALL NULL NULL NULL NULL NULL NULL Using temporary; Using filesort
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT f1 FROM t1'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "1.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 2,
"rows_produced_per_join": 2,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.40",
"prefix_cost": "1.40",
"data_read_per_join": "16"
},
"used_columns": [
"f1"
]
}
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT * FROM (SELECT * FROM t1) tt'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "1.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 2,
"rows_produced_per_join": 2,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.40",
"prefix_cost": "1.40",
"data_read_per_join": "16"
},
"used_columns": [
"f1"
]
}
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT * FROM t1 WHERE f1 IN (SELECT * FROM t1)'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "3.20"
},
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 2,
"rows_produced_per_join": 2,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.40",
"prefix_cost": "1.40",
"data_read_per_join": "16"
},
"used_columns": [
"f1"
]
}
},
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 2,
"rows_produced_per_join": 2,
"filtered": "50.00",
"using_where": true,
"first_match": "t1",
"using_join_buffer": "Block Nested Loop",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.40",
"prefix_cost": "3.20",
"data_read_per_join": "16"
},
"used_columns": [
"f1"
]
}
}
]
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT * FROM t1 UNION ALL SELECT * FROM t1 ORDER BY 1'
EXPLAIN
{
"query_block": {
"union_result": {
"using_temporary_table": true,
"table_name": "<union1,2>",
"access_type": "ALL",
"query_specifications": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "1.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 2,
"rows_produced_per_join": 2,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.40",
"prefix_cost": "1.40",
"data_read_per_join": "16"
},
"used_columns": [
"f1"
]
}
}
},
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"cost_info": {
"query_cost": "1.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 2,
"rows_produced_per_join": 2,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.40",
"prefix_cost": "1.40",
"data_read_per_join": "16"
},
"used_columns": [
"f1"
]
}
}
}
]
}
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT * FROM t1 WHERE 1=0'
EXPLAIN
{
"query_block": {
"select_id": 1,
"message": "Impossible WHERE"
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT * FROM t1
GROUP BY f1 NOT IN
(SELECT f1+10 AS f2 FROM t1 AS t2
GROUP BY f2 NOT IN
(SELECT f1+100 AS f3 FROM t1 AS t3))'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "3.40"
},
"grouping_operation": {
"using_temporary_table": true,
"using_filesort": true,
"cost_info": {
"sort_cost": "2.00"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 2,
"rows_produced_per_join": 2,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.40",
"prefix_cost": "1.40",
"data_read_per_join": "16"
},
"used_columns": [
"f1"
]
},
"group_by_subqueries": [
{
"dependent": true,
"cacheable": false,
"query_block": {
"select_id": 2,
"cost_info": {
"query_cost": "1.40"
},
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows_examined_per_scan": 2,
"rows_produced_per_join": 2,
"filtered": "100.00",
"using_where": true,
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.40",
"prefix_cost": "1.40",
"data_read_per_join": "16"
},
"used_columns": [
"f1"
]
}
}
}
]
}
}
}
Explain for non-select queries
EXPLAIN FORMAT=JSON FOR QUERY 'INSERT INTO t1 VALUES (3)'
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"insert": true,
"table_name": "t1",
"access_type": "ALL"
}
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'INSERT INTO t1 SELECT 4'
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"insert": true,
"table_name": "t1",
"access_type": "ALL"
}
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'INSERT INTO t1 SELECT f1 + 4 FROM t1'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "1.80"
},
"table": {
"insert": true,
"select_id": 1,
"table_name": "t1",
"access_type": "ALL"
},
"insert_from": {
"buffer_result": {
"using_temporary_table": true,
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 4,
"rows_produced_per_join": 4,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.80",
"prefix_cost": "1.80",
"data_read_per_join": "32"
},
"used_columns": [
"f1"
]
}
}
}
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'UPDATE t1 SET f1=4 WHERE f1=4'
EXPLAIN
{
"query_block": {
"select_id": 1,
"message": "Plan isn't ready yet"
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'UPDATE t1 SET f1=4 WHERE f1=4'
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"update": true,
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 8,
"filtered": "100.00",
"using_where": true
}
}
}
CREATE TABLE t2 (f2 int);
EXPLAIN FORMAT=JSON FOR QUERY 'UPDATE t1 SET f1=f1+0
ORDER BY f1 NOT IN
(SELECT f1+10 AS f2 FROM t2
GROUP BY f2 NOT IN
(SELECT f1+100 AS f3 FROM t2 AS t3))'
EXPLAIN
{
"query_block": {
"select_id": 1,
"ordering_operation": {
"using_filesort": true,
"table": {
"update": true,
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 8,
"filtered": "100.00"
},
"order_by_subqueries": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"message": "Plan isn't ready yet"
}
}
]
}
}
}
CREATE VIEW v1 AS SELECT t1.f1 FROM t1 JOIN t1 tt on t1.f1=tt.f1;
EXPLAIN FORMAT=JSON FOR QUERY 'UPDATE v1 SET f1=5 WHERE f1=5'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "5.20"
},
"nested_loop": [
{
"table": {
"update": true,
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 8,
"rows_produced_per_join": 1,
"filtered": "12.50",
"using_where": true,
"cost_info": {
"read_cost": "2.40",
"eval_cost": "0.20",
"prefix_cost": "2.60",
"data_read_per_join": "8"
},
"used_columns": [
"f1"
]
}
},
{
"table": {
"table_name": "tt",
"access_type": "ALL",
"rows_examined_per_scan": 8,
"rows_produced_per_join": 1,
"filtered": "12.50",
"using_where": true,
"cost_info": {
"read_cost": "2.40",
"eval_cost": "0.20",
"prefix_cost": "5.20",
"data_read_per_join": "8"
},
"used_columns": [
"f1"
]
}
}
]
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'DELETE FROM t1 WHERE f1=4'
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"delete": true,
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 8,
"filtered": "100.00",
"using_where": true
}
}
}
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'INSERT INTO t1 VALUES (3)'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 INSERT t1 NULL ALL NULL NULL NULL NULL NULL NULL NULL
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'INSERT INTO t1 SELECT 4'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 INSERT t1 NULL ALL NULL NULL NULL NULL NULL NULL NULL
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'INSERT INTO t1 SELECT f1 + 4 FROM t1'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 INSERT t1 NULL ALL NULL NULL NULL NULL NULL NULL NULL
1 SIMPLE t1 NULL ALL NULL NULL NULL NULL 9 100.00 Using temporary
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'UPDATE t1 SET f1=4 WHERE f1=4'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 UPDATE t1 NULL ALL NULL NULL NULL NULL 18 100.00 Using where
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'UPDATE v1 SET f1=5 WHERE f1=5'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 UPDATE t1 NULL ALL NULL NULL NULL NULL 18 10.00 Using where
1 SIMPLE tt NULL ALL NULL NULL NULL NULL 18 10.00 Using where
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'DELETE FROM t1 WHERE f1=4'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 DELETE t1 NULL ALL NULL NULL NULL NULL 18 100.00 Using where
Explain queries with plan only partially ready
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT * FROM (SELECT * FROM t1 GROUP BY 1) tt'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL NULL NULL Plan isn't ready yet
2 DERIVED t1 NULL ALL NULL NULL NULL NULL 17 100.00 Using temporary; Using filesort
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT * FROM t1 UNION ALL SELECT * FROM t1 ORDER BY
(SELECT * FROM t1 LIMIT 1)'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 NULL ALL NULL NULL NULL NULL 17 100.00 NULL
2 UNION NULL NULL NULL NULL NULL NULL NULL NULL NULL Plan isn't ready yet
NULL UNION RESULT NULL NULL NULL NULL NULL NULL NULL NULL NULL Plan isn't ready yet
3 SUBQUERY NULL NULL NULL NULL NULL NULL NULL NULL NULL Plan isn't ready yet
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT * FROM (SELECT * FROM t1 GROUP BY 1) tt'
EXPLAIN
{
"query_block": {
"select_id": 1,
"message": "Plan isn't ready yet",
"table": {
"materialized_from_subquery": {
"using_temporary_table": true,
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"cost_info": {
"query_cost": "21.40"
},
"grouping_operation": {
"using_temporary_table": true,
"using_filesort": true,
"cost_info": {
"sort_cost": "17.00"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 17,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "3.40",
"prefix_cost": "4.40",
"data_read_per_join": "136"
},
"used_columns": [
"f1"
]
}
}
}
}
}
}
}
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT * FROM t1 UNION ALL SELECT * FROM t1 ORDER BY
(SELECT * FROM t1 LIMIT 1)'
EXPLAIN
{
"query_block": {
"ordering_operation": {
"using_filesort": true,
"union_result": {
"using_temporary_table": true,
"message": "Plan isn't ready yet",
"query_specifications": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "4.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 17,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "3.40",
"prefix_cost": "4.40",
"data_read_per_join": "136"
},
"used_columns": [
"f1"
]
}
}
},
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"message": "Plan isn't ready yet"
}
}
]
},
"order_by_subqueries": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 3,
"message": "Plan isn't ready yet"
}
}
]
}
}
}
Ensure materialized derived still has plans after materialization
set @optimizer_switch_saved= @@optimizer_switch;
set optimizer_switch='derived_merge=off';
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT * FROM (SELECT * FROM t1) tt'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <derived2> NULL ALL NULL NULL NULL NULL 17 100.00 NULL
2 DERIVED t1 NULL ALL NULL NULL NULL NULL 17 100.00 NULL
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT * FROM (SELECT * FROM t1) tt'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "14.25"
},
"table": {
"table_name": "tt",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 17,
"filtered": "100.00",
"cost_info": {
"read_cost": "10.85",
"eval_cost": "3.40",
"prefix_cost": "14.25",
"data_read_per_join": "272"
},
"used_columns": [
"f1"
],
"materialized_from_subquery": {
"using_temporary_table": true,
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"cost_info": {
"query_cost": "4.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 17,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "3.40",
"prefix_cost": "4.40",
"data_read_per_join": "136"
},
"used_columns": [
"f1"
]
}
}
}
}
}
}
set optimizer_switch= @optimizer_switch_saved;
WHERE subqueries, neither parent query nor subquery has plan
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT t2.f1 FROM t1 STRAIGHT_JOIN t1 AS t2
WHERE t1.f1>(SELECT t3.f1 FROM t1 AS t3 LIMIT 1)'
EXPLAIN
{
"query_block": {
"select_id": 1,
"message": "Plan isn't ready yet",
"attached_subqueries": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"message": "Plan isn't ready yet"
}
}
]
}
}
the same, parent query has a plan
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT t2.f1 FROM t1 STRAIGHT_JOIN t1 AS t2
WHERE t1.f1>(SELECT t3.f1 FROM t1 AS t3 LIMIT 1)'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "24.66"
},
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 5,
"filtered": "33.33",
"using_where": true,
"cost_info": {
"read_cost": "3.27",
"eval_cost": "1.13",
"prefix_cost": "4.40",
"data_read_per_join": "45"
},
"used_columns": [
"f1"
],
"attached_subqueries": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"message": "Plan isn't ready yet"
}
}
]
}
},
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 96,
"filtered": "100.00",
"using_join_buffer": "Block Nested Loop",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "19.26",
"prefix_cost": "24.66",
"data_read_per_join": "770"
},
"used_columns": [
"f1"
]
}
}
]
}
}
the same, both have a plan
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT t2.f1 FROM t1 STRAIGHT_JOIN t1 AS t2
WHERE t1.f1>(SELECT t3.f1 FROM t1 AS t3 LIMIT 1)'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "24.66"
},
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 5,
"filtered": "33.33",
"using_where": true,
"cost_info": {
"read_cost": "3.27",
"eval_cost": "1.13",
"prefix_cost": "4.40",
"data_read_per_join": "45"
},
"used_columns": [
"f1"
],
"attached_subqueries": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"cost_info": {
"query_cost": "4.40"
},
"table": {
"table_name": "t3",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 17,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "3.40",
"prefix_cost": "4.40",
"data_read_per_join": "136"
},
"used_columns": [
"f1"
]
}
}
}
]
}
},
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 96,
"filtered": "100.00",
"using_join_buffer": "Block Nested Loop",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "19.26",
"prefix_cost": "24.66",
"data_read_per_join": "770"
},
"used_columns": [
"f1"
]
}
}
]
}
}
To be compared with regular EXPLAIN:
EXPLAIN FORMAT=JSON SELECT t2.f1 FROM t1 STRAIGHT_JOIN t1 AS t2
WHERE t1.f1>(SELECT t3.f1 FROM t1 AS t3 LIMIT 1);
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "24.66"
},
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 5,
"filtered": "33.33",
"cost_info": {
"read_cost": "3.27",
"eval_cost": "1.13",
"prefix_cost": "4.40",
"data_read_per_join": "45"
},
"used_columns": [
"f1"
],
"attached_condition": "(`mysqltest1`.`t1`.`f1` > (/* select#2 */ select `mysqltest1`.`t3`.`f1` from `mysqltest1`.`t1` `t3` limit 1))",
"attached_subqueries": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"cost_info": {
"query_cost": "4.40"
},
"table": {
"table_name": "t3",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 17,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "3.40",
"prefix_cost": "4.40",
"data_read_per_join": "136"
},
"used_columns": [
"f1"
]
}
}
}
]
}
},
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 96,
"filtered": "100.00",
"using_join_buffer": "Block Nested Loop",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "19.26",
"prefix_cost": "24.66",
"data_read_per_join": "770"
},
"used_columns": [
"f1"
]
}
}
]
}
}
Warnings:
Note 1003 /* select#1 */ select `t2`.`f1` AS `f1` from `mysqltest1`.`t1` straight_join `mysqltest1`.`t1` `t2` where (`mysqltest1`.`t1`.`f1` > (/* select#2 */ select `mysqltest1`.`t3`.`f1` from `mysqltest1`.`t1` `t3` limit 1))
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT 1 FROM t1 WHERE
ROW(f1,f1) >= ROW('1', (SELECT 1 FROM t1 WHERE f1 > 1234))'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "4.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 17,
"filtered": "100.00",
"using_where": true,
"cost_info": {
"read_cost": "1.00",
"eval_cost": "3.40",
"prefix_cost": "4.40",
"data_read_per_join": "136"
},
"used_columns": [
"f1"
]
},
"optimized_away_subqueries": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"cost_info": {
"query_cost": "4.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 5,
"filtered": "33.33",
"using_where": true,
"cost_info": {
"read_cost": "3.27",
"eval_cost": "1.13",
"prefix_cost": "4.40",
"data_read_per_join": "45"
},
"used_columns": [
"f1"
]
}
}
}
]
}
}
EXPLAIN FORMAT=JSON SELECT 1 FROM t1 WHERE
ROW(f1,f1) >= ROW('1', (SELECT 1 FROM t1 WHERE f1 > 1234));
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "4.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 17,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "3.40",
"prefix_cost": "4.40",
"data_read_per_join": "136"
},
"used_columns": [
"f1"
],
"attached_condition": "((`mysqltest1`.`t1`.`f1`,`mysqltest1`.`t1`.`f1`) >= <cache>(('1',(/* select#2 */ select 1 from `mysqltest1`.`t1` where (`t1`.`f1` > 1234)))))"
},
"optimized_away_subqueries": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"cost_info": {
"query_cost": "4.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 5,
"filtered": "33.33",
"cost_info": {
"read_cost": "3.27",
"eval_cost": "1.13",
"prefix_cost": "4.40",
"data_read_per_join": "45"
},
"used_columns": [
"f1"
],
"attached_condition": "(`t1`.`f1` > 1234)"
}
}
}
]
}
}
Warnings:
Note 1003 /* select#1 */ select 1 AS `1` from `mysqltest1`.`t1` where ((`mysqltest1`.`t1`.`f1`,`mysqltest1`.`t1`.`f1`) >= <cache>(('1',(/* select#2 */ select 1 from `mysqltest1`.`t1` where (`t1`.`f1` > 1234)))))
CREATE TABLE t3 (pk INT PRIMARY KEY);
INSERT INTO t3 SELECT DISTINCT * FROM t1;
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT * FROM t3 WHERE pk=(SELECT f1 FROM t1 limit 1)'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "1.00"
},
"table": {
"table_name": "t3",
"access_type": "const",
"possible_keys": [
"PRIMARY"
],
"key": "PRIMARY",
"used_key_parts": [
"pk"
],
"key_length": "4",
"ref": [
"const"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 1,
"filtered": "100.00",
"using_index": true,
"cost_info": {
"read_cost": "0.00",
"eval_cost": "0.20",
"prefix_cost": "0.00",
"data_read_per_join": "8"
},
"used_columns": [
"pk"
]
},
"optimized_away_subqueries": [
{
"dependent": false,
"cacheable": true,
"query_block": {
"select_id": 2,
"cost_info": {
"query_cost": "4.40"
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows_examined_per_scan": 17,
"rows_produced_per_join": 17,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "3.40",
"prefix_cost": "4.40",
"data_read_per_join": "136"
},
"used_columns": [
"f1"
]
}
}
}
]
}
}
# Check access rights checking
set @orig_sql_mode = @@sql_mode;
set sql_mode=(select replace(@@sql_mode,'NO_AUTO_CREATE_USER',''));
Warnings:
Warning 3090 Changing sql mode 'NO_AUTO_CREATE_USER' is deprecated. It will be removed in a future release.
GRANT USAGE ON *.* TO 'privtest'@'localhost';
Warnings:
Warning 1287 Using GRANT for creating new user is deprecated and will be removed in future release. Create new user with CREATE USER statement.
set sql_mode= @orig_sql_mode;
Warnings:
Warning 3090 Changing sql mode 'NO_AUTO_CREATE_USER' is deprecated. It will be removed in a future release.
GRANT SUPER ON *.* TO 'privtest'@'localhost';
GRANT SELECT ON mysqltest1.t2 TO 'privtest'@'localhost';
CREATE VIEW v2 AS SELECT * FROM t2;
GRANT SELECT,INSERT,UPDATE ON mysqltest1.v2 TO 'privtest'@'localhost';
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT f1 FROM t1'
ERROR 28000: Access denied for user 'privtest'@'localhost' (using password: NO)
SELECT f2 FROM v2;
f2
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT f2 FROM v2'
ERROR 28000: Access denied for user 'privtest'@'localhost' (using password: NO)
UPDATE v2 SET f2=1;
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'UPDATE v2 SET f2=1'
ERROR HY000: EXPLAIN/SHOW can not be issued; lacking privileges for underlying table
INSERT INTO v2 VALUES(1);
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'INSERT INTO v2 VALUES(1)'
ERROR HY000: EXPLAIN/SHOW can not be issued; lacking privileges for underlying table
INSERT INTO v2 SELECT 3 FROM t2;
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'INSERT INTO v2 SELECT 3 FROM t2'
ERROR HY000: EXPLAIN/SHOW can not be issued; lacking privileges for underlying table
SELECT f2 FROM v2;
f2
1
1
3
3
3
3
3
3
EXPLAIN SELECT f2 FROM v2;
ERROR HY000: EXPLAIN/SHOW can not be issued; lacking privileges for underlying table
DROP USER 'privtest'@localhost;
DROP VIEW v1, v2;
DROP TABLE t1, t2, t3;
#
# Bug#14586538: EXPLAIN OTHER RESULT NOT MATCHING WITH EXPLAIN
#
CREATE TABLE h2 (
pk int(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (pk)
) ENGINE=MyISAM AUTO_INCREMENT=10 DEFAULT CHARSET=latin1;
insert into h2 values (1),(2),(3),(4),(5),(6),(7),(8),(9);
CREATE TABLE aa3 (
col_int_key int(11) DEFAULT NULL,
KEY col_int_key (col_int_key)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
EXPLAIN SELECT alias1.pk AS field1 FROM h2 AS alias1 LEFT JOIN aa3 AS alias2 ON alias1.pk = alias2.col_int_key WHERE alias1.pk <> 9 GROUP BY field1 ORDER BY field1 LIMIT 1 OFFSET 3;;
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE alias1 NULL index PRIMARY PRIMARY 4 NULL 4 100.00 Using where; Using index
1 SIMPLE alias2 NULL ref col_int_key col_int_key 5 mysqltest1.alias1.pk 1 100.00 Using index
Warnings:
Note 1003 /* select#1 */ select `mysqltest1`.`alias1`.`pk` AS `field1` from `mysqltest1`.`h2` `alias1` left join `mysqltest1`.`aa3` `alias2` on((`mysqltest1`.`alias2`.`col_int_key` = `mysqltest1`.`alias1`.`pk`)) where (`mysqltest1`.`alias1`.`pk` <> 9) group by `field1` order by `field1` limit 3,1
Should show same # of rows as above
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT alias1.pk AS field1 FROM h2 AS alias1 LEFT JOIN aa3 AS alias2 ON alias1.pk = alias2.col_int_key WHERE alias1.pk <> 9 GROUP BY field1 ORDER BY field1 LIMIT 1 OFFSET 3'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE alias1 NULL index PRIMARY PRIMARY 4 NULL 4 100.00 Using where; Using index
1 SIMPLE alias2 NULL ref col_int_key col_int_key 5 mysqltest1.alias1.pk 1 100.00 Using index
DROP TABLE h2, aa3;
#
# Bug#14591376: EXPLAIN OTHER RESULT NOT MATCHING WITH EXPLAIN - REF
#
CREATE TABLE t1 (
pk int(11),
col_int_key int(11) DEFAULT NULL,
KEY col_int_key (col_int_key)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
INSERT INTO t1 VALUES (NULL,NULL);
INSERT INTO t1 VALUES (6,NULL);
INSERT INTO t1 VALUES (8,-1131610112);
INSERT INTO t1 VALUES (2,-1009057792);
INSERT INTO t1 VALUES (-1220345856,1);
INSERT INTO t1 VALUES (NULL,-185204736);
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT pk FROM t1 WHERE col_int_key= 8'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 NULL ref col_int_key col_int_key 5 const 1 100.00 NULL
DROP TABLE t1;
# From Bug#14463247 MYSQL CRASHES ON THE QUERY
#
CREATE TABLE tbl1 (
login int(11) NOT NULL,
numb decimal(15,2) NOT NULL DEFAULT '0.00',
PRIMARY KEY (login),
KEY numb (numb)
) ;
CREATE TABLE tbl2 (
login int(11) NOT NULL,
cmd tinyint(4) NOT NULL,
nump decimal(15,2) NOT NULL DEFAULT '0.00',
KEY cmd (cmd),
KEY login (login)
) ;
insert into tbl1 (login) values(1),(2);
insert ignore into tbl2 (login) values(1),(2);
Warnings:
Warning 1364 Field 'cmd' doesn't have a default value
EXPLAIN FORMAT=TRADITIONAL FOR QUERY 'SELECT
t1.login AS tlogin,
numb -
IFNULL((SELECT sum(nump) FROM tbl2 WHERE login=t1.login), 0) -
IFNULL((SELECT sum(nump) FROM tbl2 WHERE login=t1.login), 0) as sp
FROM tbl1 t1, tbl2 t2
WHERE t1.login=t2.login
GROUP BY t1.login
ORDER BY numb - IFNULL((SELECT sum(nump) FROM tbl2 WHERE login=t1.login), 0)
- IFNULL((SELECT sum(nump) FROM tbl2 WHERE login=t1.login), 0)
'
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 NULL index PRIMARY,numb PRIMARY 4 NULL 2 100.00 Using temporary; Using filesort
1 PRIMARY t2 NULL ref login login 4 mysqltest1.t1.login 1 100.00 Using index
3 DEPENDENT SUBQUERY tbl2 NULL ref login login 4 func 1 100.00 NULL
2 DEPENDENT SUBQUERY tbl2 NULL ref login login 4 func 1 100.00 NULL
EXPLAIN FORMAT=JSON FOR QUERY 'SELECT
t1.login AS tlogin,
numb -
IFNULL((SELECT sum(nump) FROM tbl2 WHERE login=t1.login), 0) -
IFNULL((SELECT sum(nump) FROM tbl2 WHERE login=t1.login), 0) as sp
FROM tbl1 t1, tbl2 t2
WHERE t1.login=t2.login
GROUP BY t1.login
ORDER BY numb - IFNULL((SELECT sum(nump) FROM tbl2 WHERE login=t1.login), 0)
- IFNULL((SELECT sum(nump) FROM tbl2 WHERE login=t1.login), 0)
'
EXPLAIN
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "3.80"
},
"ordering_operation": {
"using_temporary_table": true,
"using_filesort": true,
"grouping_operation": {
"using_filesort": false,
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "index",
"possible_keys": [
"PRIMARY",
"numb"
],
"key": "PRIMARY",
"used_key_parts": [
"login"
],
"key_length": "4",
"rows_examined_per_scan": 2,
"rows_produced_per_join": 2,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.40",
"prefix_cost": "1.40",
"data_read_per_join": "32"
},
"used_columns": [
"login",
"numb"
]
}
},
{
"table": {
"table_name": "t2",
"access_type": "ref",
"possible_keys": [
"login"
],
"key": "login",
"used_key_parts": [
"login"
],
"key_length": "4",
"ref": [
"mysqltest1.t1.login"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 2,
"filtered": "100.00",
"using_index": true,
"cost_info": {
"read_cost": "2.00",
"eval_cost": "0.40",
"prefix_cost": "3.80",
"data_read_per_join": "32"
},
"used_columns": [
"login"
]
}
}
],
"select_list_subqueries": [
{
"dependent": true,
"cacheable": false,
"query_block": {
"select_id": 3,
"cost_info": {
"query_cost": "1.20"
},
"table": {
"table_name": "tbl2",
"access_type": "ref",
"possible_keys": [
"login"
],
"key": "login",
"used_key_parts": [
"login"
],
"key_length": "4",
"ref": [
"func"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 1,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.20",
"prefix_cost": "1.20",
"data_read_per_join": "16"
},
"used_columns": [
"login",
"nump"
]
}
}
},
{
"dependent": true,
"cacheable": false,
"query_block": {
"select_id": 2,
"cost_info": {
"query_cost": "1.20"
},
"table": {
"table_name": "tbl2",
"access_type": "ref",
"possible_keys": [
"login"
],
"key": "login",
"used_key_parts": [
"login"
],
"key_length": "4",
"ref": [
"func"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 1,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.20",
"prefix_cost": "1.20",
"data_read_per_join": "16"
},
"used_columns": [
"login",
"nump"
]
}
}
}
]
}
}
}
}
DROP TABLE tbl1, tbl2;
# End of tests for WL#6369
#
# Bug#19822146 EXPLAIN FOR CONNECTION CRASHES IN
# EXPLAIN_JOIN::EXPLAIN_QEP_TAB
#
DROP TABLE IF EXISTS t1, t2;
create table t1(a char(10) charset latin1, key(a)) engine=innodb;
create table t2(a binary(10), key(a)) engine=innodb;
insert into t1 values('1'),('2'),('3');
insert into t2 values('1'),('2'),('s');
analyze table t1,t2;
Table Op Msg_type Msg_text
mysqltest1.t1 analyze status OK
mysqltest1.t2 analyze status OK
# Connection cq
# Let thread1 to suspend itself right before creating Quick object.
SET DEBUG_SYNC= 'quick_not_created SIGNAL ready_for_explain WAIT_FOR explained';
select 1 from t1 inner join t2 using(a); ;
# Connection ce
SET DEBUG_SYNC= 'now WAIT_FOR ready_for_explain';
SET DEBUG_SYNC= 'after_explain_other SIGNAL explained';
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t2 NULL index a a 11 NULL 3 100.00 Using index
1 SIMPLE t1 NULL ALL a NULL NULL NULL 3 100.00 Range checked for each record (index map: 0x1)
connection: cq
1
SET DEBUG_SYNC= 'RESET';
# Connection cq
# Let thread1 to suspend itself right before the mutex section.
SET DEBUG_SYNC= 'quick_created_before_mutex SIGNAL ready_for_explain WAIT_FOR explained';
select 1 from t1 inner join t2 using(a);;
# Connection ce
SET DEBUG_SYNC= 'now WAIT_FOR ready_for_explain';
SET DEBUG_SYNC= 'after_explain_other SIGNAL explained';
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t2 NULL index a a 11 NULL 3 100.00 Using index
1 SIMPLE t1 NULL ALL a NULL NULL NULL 3 100.00 Range checked for each record (index map: 0x1)
connection: cq
1
SET DEBUG_SYNC= 'RESET';
# Connection cq
# Let thread1 to suspend itself right after quick object is droped.
SET DEBUG_SYNC= 'quick_droped_after_mutex SIGNAL ready_for_explain WAIT_FOR explained';
select 1 from t1 inner join t2 using(a);;
# Connection ce
SET DEBUG_SYNC= 'now WAIT_FOR ready_for_explain';
SET DEBUG_SYNC= 'after_explain_other SIGNAL explained';
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t2 NULL index a a 11 NULL 3 100.00 Using index
1 SIMPLE t1 NULL range a a 11 NULL 3 100.00 Range checked for each record (index map: 0x1)
connection: cq
1
# Connection default
DROP TABLE t1, t2;
SET DEBUG_SYNC= 'RESET';
# End of test Bug#19822146
USE test;
DROP DATABASE mysqltest1;
# End of test