| Current Path : /home/usr.opt/mysql57/mysql-test/suite/opt_trace/r/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : /home/usr.opt/mysql57/mysql-test/suite/opt_trace/r/temp_table.result |
SET optimizer_trace_max_mem_size=1048576;
SET optimizer_trace="enabled=on,one_line=off";
SET end_markers_in_json="on";
CREATE TABLE tmp (
pk INT PRIMARY KEY AUTO_INCREMENT,
col1 CHAR (1)
);
INSERT INTO tmp(col1) VALUES ('a'),('b'),('c'),('d'),('e'),('f'),('g'),('h');
CREATE TABLE t1 (
uniq VARCHAR(10),
col1 VARCHAR(10),
col2 VARCHAR(1024)
);
INSERT INTO t1 SELECT pk, col1, col1 FROM tmp;
SELECT uniq, col1 FROM t1 GROUP BY col2,uniq LIMIT 3;
uniq col1
1 a
2 b
3 c
SELECT * FROM information_schema.OPTIMIZER_TRACE;
QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES
SELECT uniq, col1 FROM t1 GROUP BY col2,uniq LIMIT 3 {
"steps": [
{
"join_preparation": {
"select#": 1,
"steps": [
{
"expanded_query": "/* select#1 */ select `t1`.`uniq` AS `uniq`,`t1`.`col1` AS `col1` from `t1` group by `t1`.`col2`,`t1`.`uniq` limit 3"
}
] /* steps */
} /* join_preparation */
},
{
"join_optimization": {
"select#": 1,
"steps": [
{
"substitute_generated_columns": {
} /* substitute_generated_columns */
},
{
"table_dependencies": [
{
"table": "`t1`",
"row_may_be_null": false,
"map_bit": 0,
"depends_on_map_bits": [
] /* depends_on_map_bits */
}
] /* table_dependencies */
},
{
"rows_estimation": [
{
"table": "`t1`",
"table_scan": {
"rows": 8,
"cost": 1
} /* table_scan */
}
] /* rows_estimation */
},
{
"considered_execution_plans": [
{
"plan_prefix": [
] /* plan_prefix */,
"table": "`t1`",
"best_access_path": {
"considered_access_paths": [
{
"rows_to_scan": 8,
"access_type": "scan",
"resulting_rows": 8,
"cost": 2.6,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"condition_filtering_pct": 100,
"rows_for_plan": 8,
"cost_for_plan": 2.6,
"chosen": true
}
] /* considered_execution_plans */
},
{
"attaching_conditions_to_tables": {
"original_condition": null,
"attached_conditions_computation": [
] /* attached_conditions_computation */,
"attached_conditions_summary": [
{
"table": "`t1`",
"attached": null
}
] /* attached_conditions_summary */
} /* attaching_conditions_to_tables */
},
{
"clause_processing": {
"clause": "GROUP BY",
"original_clause": "`t1`.`col2`,`t1`.`uniq`",
"items": [
{
"item": "`t1`.`col2`"
},
{
"item": "`t1`.`uniq`"
}
] /* items */,
"resulting_clause_is_simple": true,
"resulting_clause": "`t1`.`col2`,`t1`.`uniq`"
} /* clause_processing */
},
{
"refine_plan": [
{
"table": "`t1`"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 1,
"steps": [
{
"creating_tmp_table": {
"tmp_table_info": {
"table": "intermediate_tmp_table",
"row_length": 1058,
"key_length": 8,
"unique_constraint": true,
"location": "memory (heap)",
"row_limit_estimate": 991
} /* tmp_table_info */
} /* creating_tmp_table */
},
{
"filesort_information": [
{
"direction": "asc",
"table": "intermediate_tmp_table",
"field": "col2"
},
{
"direction": "asc",
"table": "intermediate_tmp_table",
"field": "uniq"
}
] /* filesort_information */,
"filesort_priority_queue_optimization": {
"limit": 3,
"rows_estimate": 18,
"row_size": 1044,
"memory_available": 262144,
"chosen": true
} /* filesort_priority_queue_optimization */,
"filesort_execution": [
] /* filesort_execution */,
"filesort_summary": {
"rows": 4,
"examined_rows": 8,
"number_of_tmp_files": 0,
"sort_buffer_size": 4208,
"sort_mode": "<sort_key, rowid>"
} /* filesort_summary */
}
] /* steps */
} /* join_execution */
}
] /* steps */
} 0 0
SELECT uniq, col1, col2 FROM t1 GROUP BY uniq ;
uniq col1 col2
1 a a
2 b b
3 c c
4 d d
5 e e
6 f f
7 g g
8 h h
SELECT * FROM information_schema.OPTIMIZER_TRACE;
QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES
SELECT uniq, col1, col2 FROM t1 GROUP BY uniq {
"steps": [
{
"join_preparation": {
"select#": 1,
"steps": [
{
"expanded_query": "/* select#1 */ select `t1`.`uniq` AS `uniq`,`t1`.`col1` AS `col1`,`t1`.`col2` AS `col2` from `t1` group by `t1`.`uniq`"
}
] /* steps */
} /* join_preparation */
},
{
"join_optimization": {
"select#": 1,
"steps": [
{
"substitute_generated_columns": {
} /* substitute_generated_columns */
},
{
"table_dependencies": [
{
"table": "`t1`",
"row_may_be_null": false,
"map_bit": 0,
"depends_on_map_bits": [
] /* depends_on_map_bits */
}
] /* table_dependencies */
},
{
"rows_estimation": [
{
"table": "`t1`",
"table_scan": {
"rows": 8,
"cost": 1
} /* table_scan */
}
] /* rows_estimation */
},
{
"considered_execution_plans": [
{
"plan_prefix": [
] /* plan_prefix */,
"table": "`t1`",
"best_access_path": {
"considered_access_paths": [
{
"rows_to_scan": 8,
"access_type": "scan",
"resulting_rows": 8,
"cost": 2.6,
"chosen": true,
"use_tmp_table": true
}
] /* considered_access_paths */
} /* best_access_path */,
"condition_filtering_pct": 100,
"rows_for_plan": 8,
"cost_for_plan": 2.6,
"sort_cost": 8,
"new_cost_for_plan": 10.6,
"chosen": true
}
] /* considered_execution_plans */
},
{
"attaching_conditions_to_tables": {
"original_condition": null,
"attached_conditions_computation": [
] /* attached_conditions_computation */,
"attached_conditions_summary": [
{
"table": "`t1`",
"attached": null
}
] /* attached_conditions_summary */
} /* attaching_conditions_to_tables */
},
{
"clause_processing": {
"clause": "GROUP BY",
"original_clause": "`t1`.`uniq`",
"items": [
{
"item": "`t1`.`uniq`"
}
] /* items */,
"resulting_clause_is_simple": true,
"resulting_clause": "`t1`.`uniq`"
} /* clause_processing */
},
{
"refine_plan": [
{
"table": "`t1`"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 1,
"steps": [
{
"creating_tmp_table": {
"tmp_table_info": {
"table": "intermediate_tmp_table",
"row_length": 1050,
"key_length": 13,
"unique_constraint": false,
"location": "memory (heap)",
"row_limit_estimate": 998
} /* tmp_table_info */
} /* creating_tmp_table */
},
{
"filesort_information": [
{
"direction": "asc",
"table": "intermediate_tmp_table",
"field": "uniq"
}
] /* filesort_information */,
"filesort_priority_queue_optimization": {
"usable": false,
"cause": "not applicable (no LIMIT)"
} /* filesort_priority_queue_optimization */,
"filesort_execution": [
] /* filesort_execution */,
"filesort_summary": {
"rows": 8,
"examined_rows": 8,
"number_of_tmp_files": 0,
"sort_buffer_size": 488,
"sort_mode": "<sort_key, rowid>"
} /* filesort_summary */
}
] /* steps */
} /* join_execution */
}
] /* steps */
} 0 0
select @@tmp_table_size;
@@tmp_table_size
16777216
SET @old_size= @@tmp_table_size;
SET SESSION tmp_table_size= 1024;
INSERT INTO t1 SELECT pk+8, col1, col1 FROM tmp;
SELECT uniq, col1, col2 FROM t1 GROUP BY uniq;
uniq col1 col2
1 a a
10 b b
11 c c
12 d d
13 e e
14 f f
15 g g
16 h h
2 b b
3 c c
4 d d
5 e e
6 f f
7 g g
8 h h
9 a a
SELECT * FROM information_schema.OPTIMIZER_TRACE;
QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES
SELECT uniq, col1, col2 FROM t1 GROUP BY uniq {
"steps": [
{
"join_preparation": {
"select#": 1,
"steps": [
{
"expanded_query": "/* select#1 */ select `t1`.`uniq` AS `uniq`,`t1`.`col1` AS `col1`,`t1`.`col2` AS `col2` from `t1` group by `t1`.`uniq`"
}
] /* steps */
} /* join_preparation */
},
{
"join_optimization": {
"select#": 1,
"steps": [
{
"substitute_generated_columns": {
} /* substitute_generated_columns */
},
{
"table_dependencies": [
{
"table": "`t1`",
"row_may_be_null": false,
"map_bit": 0,
"depends_on_map_bits": [
] /* depends_on_map_bits */
}
] /* table_dependencies */
},
{
"rows_estimation": [
{
"table": "`t1`",
"table_scan": {
"rows": 16,
"cost": 1
} /* table_scan */
}
] /* rows_estimation */
},
{
"considered_execution_plans": [
{
"plan_prefix": [
] /* plan_prefix */,
"table": "`t1`",
"best_access_path": {
"considered_access_paths": [
{
"rows_to_scan": 16,
"access_type": "scan",
"resulting_rows": 16,
"cost": 4.2,
"chosen": true,
"use_tmp_table": true
}
] /* considered_access_paths */
} /* best_access_path */,
"condition_filtering_pct": 100,
"rows_for_plan": 16,
"cost_for_plan": 4.2,
"sort_cost": 16,
"new_cost_for_plan": 20.2,
"chosen": true
}
] /* considered_execution_plans */
},
{
"attaching_conditions_to_tables": {
"original_condition": null,
"attached_conditions_computation": [
] /* attached_conditions_computation */,
"attached_conditions_summary": [
{
"table": "`t1`",
"attached": null
}
] /* attached_conditions_summary */
} /* attaching_conditions_to_tables */
},
{
"clause_processing": {
"clause": "GROUP BY",
"original_clause": "`t1`.`uniq`",
"items": [
{
"item": "`t1`.`uniq`"
}
] /* items */,
"resulting_clause_is_simple": true,
"resulting_clause": "`t1`.`uniq`"
} /* clause_processing */
},
{
"refine_plan": [
{
"table": "`t1`"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 1,
"steps": [
{
"creating_tmp_table": {
"tmp_table_info": {
"table": "intermediate_tmp_table",
"row_length": 1050,
"key_length": 13,
"unique_constraint": false,
"location": "memory (heap)",
"row_limit_estimate": 1
} /* tmp_table_info */
} /* creating_tmp_table */
},
{
"converting_tmp_table_to_ondisk": {
"cause": "memory_table_size_exceeded",
"tmp_table_info": {
"table": "intermediate_tmp_table",
"row_length": 1050,
"key_length": 13,
"unique_constraint": false,
"location": "disk (TMP_TABLE_ENGINE)",
"record_format": "packed"
} /* tmp_table_info */
} /* converting_tmp_table_to_ondisk */
},
{
"filesort_information": [
{
"direction": "asc",
"table": "intermediate_tmp_table",
"field": "uniq"
}
] /* filesort_information */,
"filesort_priority_queue_optimization": {
"usable": false,
"cause": "not applicable (no LIMIT)"
} /* filesort_priority_queue_optimization */,
"filesort_execution": [
] /* filesort_execution */,
"filesort_summary": {
"rows": 16,
"examined_rows": 16,
"number_of_tmp_files": 0,
"sort_buffer_size": 65536,
"sort_mode": "<sort_key, rowid>"
} /* filesort_summary */
}
] /* steps */
} /* join_execution */
}
] /* steps */
} 0 0
SET GLOBAL tmp_table_size= @old_size;
SELECT pool_id FROM information_schema.innodb_buffer_page LIMIT 1;
pool_id
0
SELECT * FROM information_schema.OPTIMIZER_TRACE;
QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES
SELECT pool_id FROM information_schema.innodb_buffer_page LIMIT 1 {
"steps": [
{
"creating_tmp_table": {
"tmp_table_info": {
"row_length": 6852,
"key_length": 0,
"unique_constraint": false,
"location": "memory (heap)",
"row_limit_estimate": 1
} /* tmp_table_info */
} /* creating_tmp_table */
},
{
"join_preparation": {
"select#": 1,
"steps": [
{
"expanded_query": "/* select#1 */ select `information_schema`.`innodb_buffer_page`.`POOL_ID` AS `pool_id` from `information_schema`.`innodb_buffer_page` limit 1"
}
] /* steps */
} /* join_preparation */
},
{
"join_optimization": {
"select#": 1,
"steps": [
{
"table_dependencies": [
{
"table": "`information_schema`.`innodb_buffer_page`",
"row_may_be_null": false,
"map_bit": 0,
"depends_on_map_bits": [
] /* depends_on_map_bits */
}
] /* table_dependencies */
},
{
"rows_estimation": [
{
"table": "`information_schema`.`innodb_buffer_page`",
"table_scan": {
"rows": 2,
"cost": 10
} /* table_scan */
}
] /* rows_estimation */
},
{
"considered_execution_plans": [
{
"plan_prefix": [
] /* plan_prefix */,
"table": "`information_schema`.`innodb_buffer_page`",
"best_access_path": {
"considered_access_paths": [
{
"rows_to_scan": 2,
"access_type": "scan",
"resulting_rows": 2,
"cost": 10.5,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"condition_filtering_pct": 100,
"rows_for_plan": 2,
"cost_for_plan": 10.5,
"chosen": true
}
] /* considered_execution_plans */
},
{
"attaching_conditions_to_tables": {
"original_condition": null,
"attached_conditions_computation": [
] /* attached_conditions_computation */,
"attached_conditions_summary": [
{
"table": "`information_schema`.`innodb_buffer_page`",
"attached": null
}
] /* attached_conditions_summary */
} /* attaching_conditions_to_tables */
},
{
"refine_plan": [
{
"table": "`information_schema`.`innodb_buffer_page`"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 1,
"steps": [
{
"converting_tmp_table_to_ondisk": {
"cause": "memory_table_size_exceeded",
"tmp_table_info": {
"table": "`information_schema`.`innodb_buffer_page`",
"row_length": 6852,
"key_length": 0,
"unique_constraint": false,
"location": "disk (TMP_TABLE_ENGINE)",
"record_format": "packed"
} /* tmp_table_info */
} /* converting_tmp_table_to_ondisk */
}
] /* steps */
} /* join_execution */
}
] /* steps */
} 0 0
DROP TABLE t1, tmp;
#
# Bug#17231940: THE OPTIMIZER STILL USES FIXED LENGTH TEMPORARY TABLES
# ON DISK
#
CREATE TABLE t1 (
c1 INT AUTO_INCREMENT PRIMARY KEY,
c2 VARCHAR(250)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO t1(c2) VALUES ('b'),('b');
INSERT INTO t1(c2) SELECT t1.c2 FROM t1, t1 t2, t1 t3, t1 t4, t1 t5, t1 t6;
SET @@max_heap_table_size=1;
Warnings:
Warning 1292 Truncated incorrect max_heap_table_size value: '1'
SET @@group_concat_max_len= 500;
SELECT c1,GROUP_CONCAT(c2) cc FROM
(SELECT * FROM t1 UNION SELECT c1, 'a' FROM t1) tt
GROUP BY c1
ORDER BY cc;
c1 cc
1 a,b
2 a,b
3 a,b
4 a,b
5 a,b
6 a,b
7 a,b
8 a,b
9 a,b
10 a,b
11 a,b
12 a,b
13 a,b
14 a,b
15 a,b
16 a,b
17 a,b
18 a,b
19 a,b
20 a,b
21 a,b
22 a,b
23 a,b
24 a,b
25 a,b
26 a,b
27 a,b
28 a,b
29 a,b
30 a,b
31 a,b
32 a,b
33 a,b
34 a,b
35 a,b
36 a,b
37 a,b
38 a,b
39 a,b
40 a,b
41 a,b
42 a,b
43 a,b
44 a,b
45 a,b
46 a,b
47 a,b
48 a,b
49 a,b
50 a,b
51 a,b
52 a,b
53 a,b
54 a,b
55 a,b
56 a,b
57 a,b
58 a,b
59 a,b
60 a,b
61 a,b
62 a,b
63 a,b
64 a,b
65 a,b
66 a,b
SELECT * FROM information_schema.OPTIMIZER_TRACE;
QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES
SELECT c1,GROUP_CONCAT(c2) cc FROM
(SELECT * FROM t1 UNION SELECT c1, 'a' FROM t1) tt
GROUP BY c1
ORDER BY cc {
"steps": [
{
"join_preparation": {
"select#": 1,
"steps": [
{
"join_preparation": {
"select#": 2,
"steps": [
{
"expanded_query": "/* select#2 */ select `t1`.`c1` AS `c1`,`t1`.`c2` AS `c2` from `t1`"
}
] /* steps */
} /* join_preparation */
},
{
"join_preparation": {
"select#": 3,
"steps": [
{
"expanded_query": "/* select#3 */ select `t1`.`c1` AS `c1`,'a' AS `a` from `t1`"
}
] /* steps */
} /* join_preparation */
},
{
"creating_tmp_table": {
"tmp_table_info": {
"table": "intermediate_tmp_table",
"row_length": 757,
"key_length": 757,
"unique_constraint": false,
"location": "memory (heap)",
"row_limit_estimate": 1
} /* tmp_table_info */
} /* creating_tmp_table */
},
{
"join_preparation": {
"select#": "fake",
"steps": [
{
"expanded_query": "/* select#fake */ select `c1` AS `c1`,`c2` AS `c2` from dual"
}
] /* steps */
} /* join_preparation */
},
{
"derived": {
"table": " `tt`",
"select#": 2,
"materialized": true
} /* derived */
},
{
"expanded_query": "/* select#1 */ select `tt`.`c1` AS `c1`,group_concat(`tt`.`c2` separator ',') AS `cc` from (/* select#2 */ select `t1`.`c1` AS `c1`,`t1`.`c2` AS `c2` from `t1` union /* select#3 */ select `t1`.`c1` AS `c1`,'a' AS `a` from `t1`) `tt` group by `tt`.`c1` order by `cc`"
}
] /* steps */
} /* join_preparation */
},
{
"join_optimization": {
"select#": 1,
"steps": [
{
"join_optimization": {
"select#": 2,
"steps": [
{
"table_dependencies": [
{
"table": "`t1`",
"row_may_be_null": false,
"map_bit": 0,
"depends_on_map_bits": [
] /* depends_on_map_bits */
}
] /* table_dependencies */
},
{
"rows_estimation": [
{
"table": "`t1`",
"table_scan": {
"rows": 66,
"cost": 1
} /* table_scan */
}
] /* rows_estimation */
},
{
"considered_execution_plans": [
{
"plan_prefix": [
] /* plan_prefix */,
"table": "`t1`",
"best_access_path": {
"considered_access_paths": [
{
"rows_to_scan": 66,
"access_type": "scan",
"resulting_rows": 66,
"cost": 14.2,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"condition_filtering_pct": 100,
"rows_for_plan": 66,
"cost_for_plan": 14.2,
"chosen": true
}
] /* considered_execution_plans */
},
{
"attaching_conditions_to_tables": {
"original_condition": null,
"attached_conditions_computation": [
] /* attached_conditions_computation */,
"attached_conditions_summary": [
{
"table": "`t1`",
"attached": null
}
] /* attached_conditions_summary */
} /* attaching_conditions_to_tables */
},
{
"refine_plan": [
{
"table": "`t1`"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_optimization": {
"select#": 3,
"steps": [
{
"table_dependencies": [
{
"table": "`t1`",
"row_may_be_null": false,
"map_bit": 0,
"depends_on_map_bits": [
] /* depends_on_map_bits */
}
] /* table_dependencies */
},
{
"rows_estimation": [
{
"table": "`t1`",
"table_scan": {
"rows": 66,
"cost": 1
} /* table_scan */
}
] /* rows_estimation */
},
{
"considered_execution_plans": [
{
"plan_prefix": [
] /* plan_prefix */,
"table": "`t1`",
"best_access_path": {
"considered_access_paths": [
{
"rows_to_scan": 66,
"access_type": "scan",
"resulting_rows": 66,
"cost": 14.2,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"condition_filtering_pct": 100,
"rows_for_plan": 66,
"cost_for_plan": 14.2,
"chosen": true
}
] /* considered_execution_plans */
},
{
"attaching_conditions_to_tables": {
"original_condition": null,
"attached_conditions_computation": [
] /* attached_conditions_computation */,
"attached_conditions_summary": [
{
"table": "`t1`",
"attached": null
}
] /* attached_conditions_summary */
} /* attaching_conditions_to_tables */
},
{
"refine_plan": [
{
"table": "`t1`"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_optimization": {
"select#": "fake",
"steps": [
{
"table_dependencies": [
{
"table": "``.``",
"row_may_be_null": false,
"map_bit": 0,
"depends_on_map_bits": [
] /* depends_on_map_bits */
}
] /* table_dependencies */
},
{
"rows_estimation": [
{
"table": "``.``",
"table_scan": {
"rows": 0,
"cost": 10
} /* table_scan */
}
] /* rows_estimation */
},
{
"considered_execution_plans": [
{
"plan_prefix": [
] /* plan_prefix */,
"table": "``.``",
"best_access_path": {
"considered_access_paths": [
{
"rows_to_scan": 0,
"access_type": "scan",
"resulting_rows": 0,
"cost": 10,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"condition_filtering_pct": 100,
"rows_for_plan": 0,
"cost_for_plan": 10,
"chosen": true
}
] /* considered_execution_plans */
},
{
"attaching_conditions_to_tables": {
"original_condition": null,
"attached_conditions_computation": [
] /* attached_conditions_computation */,
"attached_conditions_summary": [
{
"table": "``.``",
"attached": null
}
] /* attached_conditions_summary */
} /* attaching_conditions_to_tables */
},
{
"refine_plan": [
{
"table": "``.``"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"substitute_generated_columns": {
} /* substitute_generated_columns */
},
{
"table_dependencies": [
{
"table": " `tt`",
"row_may_be_null": false,
"map_bit": 0,
"depends_on_map_bits": [
] /* depends_on_map_bits */
}
] /* table_dependencies */
},
{
"rows_estimation": [
{
"table": " `tt`",
"table_scan": {
"rows": 132,
"cost": 16
} /* table_scan */
}
] /* rows_estimation */
},
{
"considered_execution_plans": [
{
"plan_prefix": [
] /* plan_prefix */,
"table": " `tt`",
"best_access_path": {
"considered_access_paths": [
{
"rows_to_scan": 132,
"access_type": "scan",
"resulting_rows": 132,
"cost": 43,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"condition_filtering_pct": 100,
"rows_for_plan": 132,
"cost_for_plan": 43,
"chosen": true
}
] /* considered_execution_plans */
},
{
"attaching_conditions_to_tables": {
"original_condition": null,
"attached_conditions_computation": [
] /* attached_conditions_computation */,
"attached_conditions_summary": [
{
"table": " `tt`",
"attached": null
}
] /* attached_conditions_summary */
} /* attaching_conditions_to_tables */
},
{
"clause_processing": {
"clause": "ORDER BY",
"original_clause": "`cc`",
"items": [
{
"item": "group_concat(`tt`.`c2` separator ',')"
}
] /* items */,
"resulting_clause_is_simple": false,
"resulting_clause": "`cc`"
} /* clause_processing */
},
{
"clause_processing": {
"clause": "GROUP BY",
"original_clause": "`tt`.`c1`",
"items": [
{
"item": "`tt`.`c1`"
}
] /* items */,
"resulting_clause_is_simple": true,
"resulting_clause": "`tt`.`c1`"
} /* clause_processing */
},
{
"refine_plan": [
{
"table": " `tt`"
}
] /* refine_plan */
},
{
"creating_tmp_table": {
"tmp_table_info": {
"table": "intermediate_tmp_table",
"row_length": 753,
"key_length": 0,
"unique_constraint": false,
"location": "memory (heap)",
"row_limit_estimate": 1
} /* tmp_table_info */
} /* creating_tmp_table */
}
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 1,
"steps": [
{
"creating_tmp_table": {
"tmp_table_info": {
"table": " `tt`",
"row_length": 757,
"key_length": 0,
"unique_constraint": false,
"location": "memory (heap)",
"row_limit_estimate": 1
} /* tmp_table_info */
} /* creating_tmp_table */
},
{
"join_execution": {
"select#": 2,
"steps": [
{
"converting_tmp_table_to_ondisk": {
"cause": "memory_table_size_exceeded",
"tmp_table_info": {
"table": "intermediate_tmp_table",
"row_length": 757,
"key_length": 757,
"unique_constraint": false,
"location": "disk (TMP_TABLE_ENGINE)",
"record_format": "packed"
} /* tmp_table_info */
} /* converting_tmp_table_to_ondisk */
}
] /* steps */
} /* join_execution */
},
{
"join_execution": {
"select#": 3,
"steps": [
] /* steps */
} /* join_execution */
},
{
"join_execution": {
"select#": "fake",
"steps": [
{
"converting_tmp_table_to_ondisk": {
"cause": "memory_table_size_exceeded",
"tmp_table_info": {
"table": " `tt`",
"row_length": 757,
"key_length": 0,
"unique_constraint": false,
"location": "disk (TMP_TABLE_ENGINE)",
"record_format": "packed"
} /* tmp_table_info */
} /* converting_tmp_table_to_ondisk */
}
] /* steps */
} /* join_execution */
},
{
"filesort_information": [
{
"direction": "asc",
"table": " `tt`",
"field": "c1"
}
] /* filesort_information */,
"filesort_priority_queue_optimization": {
"usable": false,
"cause": "not applicable (no LIMIT)"
} /* filesort_priority_queue_optimization */,
"filesort_execution": [
] /* filesort_execution */,
"filesort_summary": {
"rows": 132,
"examined_rows": 132,
"number_of_tmp_files": 0,
"sort_buffer_size": 262144,
"sort_mode": "<sort_key, packed_additional_fields>"
} /* filesort_summary */
},
{
"creating_tmp_table": {
"tmp_table_info": {
"table": "intermediate_tmp_table",
"row_length": 1507,
"key_length": 0,
"unique_constraint": false,
"location": "memory (heap)",
"row_limit_estimate": 1
} /* tmp_table_info */
} /* creating_tmp_table */
},
{
"converting_tmp_table_to_ondisk": {
"cause": "memory_table_size_exceeded",
"tmp_table_info": {
"table": "intermediate_tmp_table",
"row_length": 1507,
"key_length": 0,
"unique_constraint": false,
"location": "disk (TMP_TABLE_ENGINE)",
"record_format": "packed"
} /* tmp_table_info */
} /* converting_tmp_table_to_ondisk */
},
{
"filesort_information": [
{
"direction": "asc",
"table": "intermediate_tmp_table",
"field": "cc"
}
] /* filesort_information */,
"filesort_priority_queue_optimization": {
"usable": false,
"cause": "not applicable (no LIMIT)"
} /* filesort_priority_queue_optimization */,
"filesort_execution": [
] /* filesort_execution */,
"filesort_summary": {
"rows": 66,
"examined_rows": 66,
"number_of_tmp_files": 0,
"sort_buffer_size": 261872,
"sort_mode": "<sort_key, rowid>"
} /* filesort_summary */
}
] /* steps */
} /* join_execution */
}
] /* steps */
} 0 0
DROP TABLE t1;
#