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MDEV-34041 Display additional information for materialized subqueries in EXPLAIN/ANALYZE FORMAT=JSON

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This commits adds the "materialization" block to the output of
EXPLAIN/ANALYZE FORMAT=JSON when materialized subqueries are involved
into processing. In the case of ANALYZE additional runtime information
is displayed, such as:
  - chosen strategy of materialization
  - number of partial match/index lookup loops
  - sizes of partial match buffers
This commit is contained in:
Oleg Smirnov 2024-05-04 19:50:55 +07:00
parent a5e4c34991
commit aae3233c4f
14 changed files with 2024 additions and 615 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
mysql-test/include/analyze-format.inc
View File

@ -1,3 +1,3 @@
# The time on ANALYSE FORMAT=JSON is rather variable
--replace_regex /("(r_[a-z_]*_time_ms|r_buffer_size)": )[^, \n]*/\1"REPLACED"/
--replace_regex /("(r_[a-z_]*_time_ms|r_buffer_size|r_partial_match_buffer_size)": )[^, \n]*/\1"REPLACED"/

30
mysql-test/main/analyze_format_json.result
View File

@ -659,20 +659,24 @@ ANALYZE
},
"subqueries": [
{
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "ALL",
"materialization": {
"r_strategy": "index_lookup",
"r_loops": 2,
"query_block": {
"select_id": 2,
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}

210
mysql-test/main/derived_cond_pushdown.result
View File

@ -7671,10 +7671,12 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 2,
"table": {
"message": "Select tables optimized away"
"materialization": {
"query_block": {
"select_id": 2,
"table": {
"message": "Select tables optimized away"
}
}
}
}
@ -7731,10 +7733,12 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 2,
"table": {
"message": "Select tables optimized away"
"materialization": {
"query_block": {
"select_id": 2,
"table": {
"message": "Select tables optimized away"
}
}
}
}
@ -7815,10 +7819,12 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
"materialization": {
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
}
}
}
}
@ -7872,10 +7878,12 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
"materialization": {
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
}
}
}
}
@ -7924,10 +7932,12 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
"materialization": {
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
}
}
}
}
@ -7976,10 +7986,12 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
"materialization": {
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
}
}
}
}
@ -8030,10 +8042,12 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
"materialization": {
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
}
}
}
}
@ -8082,10 +8096,12 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
"materialization": {
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
}
}
}
}
@ -8134,10 +8150,12 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
"materialization": {
"query_block": {
"select_id": 3,
"table": {
"message": "Select tables optimized away"
}
}
}
}
@ -8223,10 +8241,12 @@ EXPLAIN
},
"subqueries": [
{
"query_block": {
"select_id": 2,
"table": {
"message": "Impossible WHERE"
"materialization": {
"query_block": {
"select_id": 2,
"table": {
"message": "Impossible WHERE"
}
}
}
}
@ -9294,27 +9314,29 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 2,
"temporary_table": {
"table": {
"table_name": "<derived3>",
"access_type": "ALL",
"rows": 5,
"filtered": 100,
"attached_condition": "d_tab.e > 1",
"materialized": {
"query_block": {
"select_id": 3,
"filesort": {
"sort_key": "t2.e",
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 5,
"filtered": 100,
"attached_condition": "t2.e > 1"
"materialization": {
"query_block": {
"select_id": 2,
"temporary_table": {
"table": {
"table_name": "<derived3>",
"access_type": "ALL",
"rows": 5,
"filtered": 100,
"attached_condition": "d_tab.e > 1",
"materialized": {
"query_block": {
"select_id": 3,
"filesort": {
"sort_key": "t2.e",
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 5,
"filtered": 100,
"attached_condition": "t2.e > 1"
}
}
}
}
@ -9396,27 +9418,29 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 2,
"temporary_table": {
"table": {
"table_name": "<derived3>",
"access_type": "ALL",
"rows": 5,
"filtered": 100,
"attached_condition": "d_tab.max_f > 20",
"materialized": {
"query_block": {
"select_id": 3,
"having_condition": "max_f > 20",
"filesort": {
"sort_key": "t2.e",
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 5,
"filtered": 100
"materialization": {
"query_block": {
"select_id": 2,
"temporary_table": {
"table": {
"table_name": "<derived3>",
"access_type": "ALL",
"rows": 5,
"filtered": 100,
"attached_condition": "d_tab.max_f > 20",
"materialized": {
"query_block": {
"select_id": 3,
"having_condition": "max_f > 20",
"filesort": {
"sort_key": "t2.e",
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 5,
"filtered": 100
}
}
}
}
@ -10826,16 +10850,18 @@ EXPLAIN
"attached_condition": "t4.c = `<subquery2>`.`sum(b)`",
"materialized": {
"unique": 1,
"query_block": {
"select_id": 2,
"having_condition": "`f1(a)` > 1 and `sum(b)` > 123",
"temporary_table": {
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows": 3,
"filtered": 100,
"attached_condition": "t1.a + 1 > 10"
"materialization": {
"query_block": {
"select_id": 2,
"having_condition": "`f1(a)` > 1 and `sum(b)` > 123",
"temporary_table": {
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows": 3,
"filtered": 100,
"attached_condition": "t1.a + 1 > 10"
}
}
}
}

34
mysql-test/main/explain_json.result
View File

@ -574,14 +574,16 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 2,
"temporary_table": {
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows": 10,
"filtered": 100
"materialization": {
"query_block": {
"select_id": 2,
"temporary_table": {
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows": 10,
"filtered": 100
}
}
}
}
@ -906,13 +908,15 @@ EXPLAIN
},
"subqueries": [
{
"query_block": {
"select_id": 2,
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 2,
"filtered": 100
"materialization": {
"query_block": {
"select_id": 2,
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 2,
"filtered": 100
}
}
}
}

84
mysql-test/main/having_cond_pushdown.result
View File

@ -1134,15 +1134,17 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 2,
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "t2.x < 5 and t2.x > 1"
"materialization": {
"query_block": {
"select_id": 2,
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "t2.x < 5 and t2.x > 1"
}
}
}
}
@ -1183,15 +1185,17 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 3,
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "t2.x < 5 and t2.x > 1"
"materialization": {
"query_block": {
"select_id": 3,
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "t2.x < 5 and t2.x > 1"
}
}
}
}
@ -1257,16 +1261,18 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 2,
"having_condition": "`MAX(t2.y)` < 14",
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "t2.x < 5"
"materialization": {
"query_block": {
"select_id": 2,
"having_condition": "`MAX(t2.y)` < 14",
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "t2.x < 5"
}
}
}
}
@ -1307,16 +1313,18 @@ EXPLAIN
"filtered": 100,
"materialized": {
"unique": 1,
"query_block": {
"select_id": 3,
"having_condition": "`MAX(t2.y)` < 14",
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "t2.x < 5"
"materialization": {
"query_block": {
"select_id": 3,
"having_condition": "`MAX(t2.y)` < 14",
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "t2.x < 5"
}
}
}
}

966
mysql-test/main/in_subq_cond_pushdown.result
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File diff suppressed because it is too large Load Diff

945
mysql-test/main/subselect_mat_analyze_json.result Normal file
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@ -0,0 +1,945 @@
set @save_optimizer_switch=@@optimizer_switch;
create table t1 (a int);
create table t2 (b int);
insert into t1 values (null), (1), (2), (3);
insert into t2 values (3), (4);
set @@optimizer_switch = "materialization=on,in_to_exists=off,semijoin=off";
explain format=json select * from t1 where a in (select b from t2);
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "<in_optimizer>(t1.a,t1.a in (subquery#2))"
},
"subqueries": [
{
"materialization": {
"query_block": {
"select_id": 2,
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 2,
"filtered": 100
}
}
}
}
]
}
}
# "Complete match" execution strategy
analyze format=json select * from t1 where a in (select b from t2);
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 25,
"attached_condition": "<in_optimizer>(t1.a,t1.a in (subquery#2))"
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup",
"r_loops": 3,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
# "Partial match" is used due to NOT IN
# Force rowid-merge partial partial matching
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off";
analyze format=json select * from t1 where a not in (select b from t2);
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 50,
"attached_condition": "!<in_optimizer>(t1.a,t1.a in (subquery#2))"
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;array merge for partial match",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"r_partial_match_buffer_size": "REPLACED",
"r_partial_match_array_sizes": ["2"],
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
# Force table scan partial matching
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=on";
analyze format=json select * from t1 where a not in (select b from t2);
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 50,
"attached_condition": "!<in_optimizer>(t1.a,t1.a in (subquery#2))"
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
# Subselect in GROUP BY
analyze format=json select a from t1 group by a in (select b from t2);
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"filesort": {
"sort_key": "<in_optimizer>(t1.a,t1.a in (subquery#2))",
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"r_used_priority_queue": false,
"r_output_rows": 3,
"r_buffer_size": "REPLACED",
"r_sort_mode": "sort_key,rowid",
"temporary_table": {
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
}
}
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off";
analyze format=json select a from t1 group by a not in (select b from t2);
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"filesort": {
"sort_key": "!<in_optimizer>(t1.a,t1.a in (subquery#2))",
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"r_used_priority_queue": false,
"r_output_rows": 3,
"r_buffer_size": "REPLACED",
"r_sort_mode": "sort_key,rowid",
"temporary_table": {
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;array merge for partial match",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"r_partial_match_buffer_size": "REPLACED",
"r_partial_match_array_sizes": ["2"],
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
}
}
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=on";
# Subselect in ORDER BY
analyze format=json select a from t1 order by a in (select b from t2);
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"read_sorted_file": {
"r_rows": 4,
"filesort": {
"sort_key": "<in_optimizer>(t1.a,t1.a in (subquery#2))",
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"r_used_priority_queue": false,
"r_output_rows": 4,
"r_buffer_size": "REPLACED",
"r_sort_mode": "sort_key,addon_fields",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
# Subselect in HAVING
analyze format=json select a from t1 having a not in (select b from t2);
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"having_condition": "!<in_optimizer>(t1.a,t1.a in (subquery#2))",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
# Nested IN
analyze format=json select a from t1 where a in (select a from t1 where a in (select b from t2));
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 25,
"attached_condition": "<in_optimizer>(t1.a,t1.a in (subquery#2))"
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup",
"r_loops": 3,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 25,
"attached_condition": "<in_optimizer>(t1.a,t1.a in (subquery#3))"
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup",
"r_loops": 3,
"query_block": {
"select_id": 3,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
}
]
}
}
create table t3 (c int);
insert into t3 (c) values (3), (null), (4);
# Subquery in ON-clause of outer join
analyze format=json select a from t1 left join t2 on a not in (select c from t3);
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"const_condition": "1",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
},
"block-nl-join": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
},
"buffer_type": "flat",
"buffer_size": "87",
"join_type": "BNL",
"attached_condition": "trigcond(trigcond(!<in_optimizer>(t1.a,t1.a in (subquery#2))))",
"r_filtered": 50,
"r_unpack_time_ms": "REPLACED"
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 4,
"r_index_lookups": 3,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t3",
"access_type": "ALL",
"r_loops": 1,
"rows": 3,
"r_rows": 3,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
analyze format=json
select (b, b + 1, b + 2) not in
(select count(distinct a), a + 1, a + 2 from t1 group by a + 1, a + 2)
from t2;
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 2,
"r_index_lookups": 2,
"r_partial_matches": 2,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"read_sorted_file": {
"r_rows": 4,
"filesort": {
"sort_key": "t1.a + 1, t1.a + 2",
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"r_used_priority_queue": false,
"r_output_rows": 4,
"r_buffer_size": "REPLACED",
"r_sort_mode": "sort_key,addon_fields",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
}
}
]
}
}
drop table t1, t2, t3;
#
# Tables with more than one column
#
create table t1 (a1 char(1), a2 char(1));
insert into t1 values (null, 'b');
create table t2 (b1 char(1), b2 char(2));
insert into t2 values ('a','b'), ('c', 'd'), (null, 'e'), ('f', 'g');
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off";
explain format=json select * from t1 where (a1, a2) not in (select b1, b2 from t2);
EXPLAIN
{
"query_block": {
"select_id": 1,
"const_condition": "!<in_optimizer>((NULL,'b'),(NULL,'b') in (subquery#2))",
"table": {
"table_name": "t1",
"access_type": "system",
"rows": 1,
"filtered": 100
},
"subqueries": [
{
"materialization": {
"query_block": {
"select_id": 2,
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100
}
}
}
}
]
}
}
analyze format=json select * from t1 where (a1, a2) not in (select b1, b2 from t2);
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"const_condition": "!<in_optimizer>((NULL,'b'),(NULL,'b') in (subquery#2))",
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"filtered": 100,
"r_filtered": null
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;array merge for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"r_partial_match_buffer_size": "REPLACED",
"r_partial_match_array_sizes": ["4", "3"],
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=on";
analyze format=json select * from t1 where (a1, a2) not in (select b1, b2 from t2);
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"const_condition": "!<in_optimizer>((NULL,'b'),(NULL,'b') in (subquery#2))",
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"filtered": 100,
"r_filtered": null
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
# Subquery in SELECT list
explain format=json select t1.*, (a1, a2) in (select * from t2) as in_res from t1;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t1",
"access_type": "system",
"rows": 1,
"filtered": 100
},
"subqueries": [
{
"materialization": {
"query_block": {
"select_id": 2,
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100
}
}
}
}
]
}
}
analyze format=json select t1.*, (a1, a2) in (select * from t2) as in_res from t1;
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"filtered": 100,
"r_filtered": null
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
analyze format=json select t1.*, (a1, a2) not in (select * from t2) as in_res from t1;
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"filtered": 100,
"r_filtered": null
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off";
analyze format=json select t1.*, (a1, a2) in (select * from t2) as in_res from t1;
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"filtered": 100,
"r_filtered": null
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;array merge for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"r_partial_match_buffer_size": "REPLACED",
"r_partial_match_array_sizes": ["4", "3"],
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
analyze format=json select t1.*, (a1, a2) not in (select * from t2) as in_res from t1;
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"filtered": 100,
"r_filtered": null
},
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;array merge for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"r_partial_match_buffer_size": "REPLACED",
"r_partial_match_array_sizes": ["4", "3"],
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
drop table t1,t2;
set @@optimizer_switch=@save_optimizer_switch;

99
mysql-test/main/subselect_mat_analyze_json.test Normal file
View File

@ -0,0 +1,99 @@
set @save_optimizer_switch=@@optimizer_switch;
create table t1 (a int);
create table t2 (b int);
insert into t1 values (null), (1), (2), (3);
insert into t2 values (3), (4);
set @@optimizer_switch = "materialization=on,in_to_exists=off,semijoin=off";
explain format=json select * from t1 where a in (select b from t2);
--echo # "Complete match" execution strategy
--source include/analyze-format.inc
analyze format=json select * from t1 where a in (select b from t2);
--echo # "Partial match" is used due to NOT IN
--echo # Force rowid-merge partial partial matching
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off";
--source include/analyze-format.inc
analyze format=json select * from t1 where a not in (select b from t2);
--echo # Force table scan partial matching
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=on";
--source include/analyze-format.inc
analyze format=json select * from t1 where a not in (select b from t2);
--echo # Subselect in GROUP BY
--source include/analyze-format.inc
analyze format=json select a from t1 group by a in (select b from t2);
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off";
--source include/analyze-format.inc
analyze format=json select a from t1 group by a not in (select b from t2);
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=on";
--echo # Subselect in ORDER BY
--source include/analyze-format.inc
analyze format=json select a from t1 order by a in (select b from t2);
--echo # Subselect in HAVING
--source include/analyze-format.inc
analyze format=json select a from t1 having a not in (select b from t2);
--echo # Nested IN
--source include/analyze-format.inc
analyze format=json select a from t1 where a in (select a from t1 where a in (select b from t2));
create table t3 (c int);
insert into t3 (c) values (3), (null), (4);
--echo # Subquery in ON-clause of outer join
--source include/analyze-format.inc
analyze format=json select a from t1 left join t2 on a not in (select c from t3);
--source include/analyze-format.inc
analyze format=json
select (b, b + 1, b + 2) not in
(select count(distinct a), a + 1, a + 2 from t1 group by a + 1, a + 2)
from t2;
drop table t1, t2, t3;
--echo #
--echo # Tables with more than one column
--echo #
create table t1 (a1 char(1), a2 char(1));
insert into t1 values (null, 'b');
create table t2 (b1 char(1), b2 char(2));
insert into t2 values ('a','b'), ('c', 'd'), (null, 'e'), ('f', 'g');
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off";
explain format=json select * from t1 where (a1, a2) not in (select b1, b2 from t2);
--source include/analyze-format.inc
analyze format=json select * from t1 where (a1, a2) not in (select b1, b2 from t2);
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=on";
--source include/analyze-format.inc
analyze format=json select * from t1 where (a1, a2) not in (select b1, b2 from t2);
--echo # Subquery in SELECT list
explain format=json select t1.*, (a1, a2) in (select * from t2) as in_res from t1;
--source include/analyze-format.inc
analyze format=json select t1.*, (a1, a2) in (select * from t2) as in_res from t1;
--source include/analyze-format.inc
analyze format=json select t1.*, (a1, a2) not in (select * from t2) as in_res from t1;
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off";
--source include/analyze-format.inc
analyze format=json select t1.*, (a1, a2) in (select * from t2) as in_res from t1;
--source include/analyze-format.inc
analyze format=json select t1.*, (a1, a2) not in (select * from t2) as in_res from t1;
drop table t1,t2;
set @@optimizer_switch=@save_optimizer_switch;

47
sql/item_subselect.cc
View File

@ -42,6 +42,7 @@
#include "sql_parse.h" // check_stack_overrun
#include "sql_cte.h"
#include "sql_test.h"
#include "my_json_writer.h"
double get_post_group_estimate(JOIN* join, double join_op_rows);
@ -192,6 +193,7 @@ void Item_in_subselect::cleanup()
in_strategy&= ~SUBS_STRATEGY_CHOSEN;
*/
first_execution= TRUE;
materialization_tracker= NULL;
pushed_cond_guards= NULL;
Item_subselect::cleanup();
DBUG_VOID_RETURN;
@ -1602,6 +1604,7 @@ Item_in_subselect::Item_in_subselect(THD *thd, Item * left_exp,
st_select_lex *select_lex):
Item_exists_subselect(thd), left_expr_cache(0), first_execution(TRUE),
in_strategy(SUBS_NOT_TRANSFORMED),
materialization_tracker(NULL),
pushed_cond_guards(NULL), do_not_convert_to_sj(FALSE), is_jtbm_merged(FALSE),
is_jtbm_const_tab(FALSE), is_flattenable_semijoin(FALSE),
is_registered_semijoin(FALSE),
@ -3648,6 +3651,26 @@ bool Item_in_subselect::init_cond_guards()
return FALSE;
}
/**
Initialize the tracker which will be used to provide information for
the output of EXPLAIN and ANALYZE
*/
void Item_in_subselect::init_subq_materialization_tracker(THD *thd)
{
if (test_strategy(SUBS_MATERIALIZATION | SUBS_PARTIAL_MATCH_ROWID_MERGE |
SUBS_PARTIAL_MATCH_TABLE_SCAN))
{
Explain_query *qw= thd->lex->explain;
DBUG_ASSERT(qw);
Explain_node *node= qw->get_node(unit->first_select()->select_number);
if (!node)
return;
node->subq_materialization= new(qw->mem_root)
Explain_subq_materialization(qw->mem_root);
materialization_tracker= node->subq_materialization->get_tracker();
}
}
bool
Item_allany_subselect::select_transformer(JOIN *join)
@ -4245,11 +4268,13 @@ int subselect_uniquesubquery_engine::exec()
empty_result_set= TRUE;
table->status= 0;
Item_in_subselect *in_subs= item->get_IN_subquery();
Subq_materialization_tracker *tracker= in_subs->get_materialization_tracker();
DBUG_ASSERT(in_subs);
if (!tab->preread_init_done && tab->preread_init())
DBUG_RETURN(1);
if (tracker)
tracker->increment_loops_count();
if (in_subs->left_expr_has_null())
{
/*
@ -5002,6 +5027,9 @@ subselect_hash_sj_engine::choose_partial_match_strategy(
partial_match_key_parts_arg);
if (pm_buff_size > thd->variables.rowid_merge_buff_size)
strategy= PARTIAL_MATCH_SCAN;
else
item->get_IN_subquery()->get_materialization_tracker()->
report_partial_match_buffer_size(pm_buff_size);
}
}
@ -5777,6 +5805,7 @@ int subselect_hash_sj_engine::exec()
}
}
item_in->get_materialization_tracker()->report_exec_strategy(strategy);
if (pm_engine)
lookup_engine= pm_engine;
item_in->change_engine(lookup_engine);
@ -6247,6 +6276,9 @@ int subselect_partial_match_engine::exec()
DBUG_ASSERT(!(item_in->left_expr_has_null() &&
item_in->is_top_level_item()));
Subq_materialization_tracker *tracker= item_in->get_materialization_tracker();
tracker->increment_loops_count();
if (!item_in->left_expr_has_null())
{
/* Try to find a matching row by index lookup. */
@ -6260,6 +6292,7 @@ int subselect_partial_match_engine::exec()
else
{
/* Search for a complete match. */
tracker->increment_index_lookups();
if ((lookup_res= lookup_engine->index_lookup()))
{
/* An error occurred during lookup(). */
@ -6304,6 +6337,7 @@ int subselect_partial_match_engine::exec()
if (tmp_table->file->inited)
tmp_table->file->ha_index_end();
tracker->increment_partial_matches();
if (partial_match())
{
/* The result of IN is UNKNOWN. */
@ -6510,6 +6544,8 @@ subselect_rowid_merge_engine::init(MY_BITMAP *non_null_key_parts,
0, 0))
return TRUE;
item->get_IN_subquery()->get_materialization_tracker()->
report_partial_merge_keys(merge_keys, merge_keys_count);
return FALSE;
}
@ -6966,3 +7002,12 @@ void Item_subselect::init_expr_cache_tracker(THD *thd)
DBUG_ASSERT(expr_cache->type() == Item::EXPR_CACHE_ITEM);
node->cache_tracker= ((Item_cache_wrapper *)expr_cache)->init_tracker(qw->mem_root);
}
void Subq_materialization_tracker::report_partial_merge_keys(
Ordered_key **merge_keys, uint merge_keys_count)
{
partial_match_array_sizes.resize(merge_keys_count, 0);
for (uint i= 0; i < merge_keys_count; i++)
partial_match_array_sizes[i]= merge_keys[i]->get_key_buff_elements();
}

119
sql/item_subselect.h
View File

@ -18,6 +18,7 @@
/* subselect Item */
#include "item.h"
#ifdef USE_PRAGMA_INTERFACE
#pragma interface /* gcc class implementation */
#endif
@ -43,6 +44,8 @@ typedef class st_select_lex SELECT_LEX;
*/
typedef Comp_creator* (*chooser_compare_func_creator)(bool invert);
class Cached_item;
class Subq_materialization_tracker;
class Explain_subq_materialization;
/* base class for subselects */
@ -501,6 +504,8 @@ protected:
bool was_null;
/* A bitmap of possible execution strategies for an IN predicate. */
uchar in_strategy;
/* Tracker collecting execution parameters of a materialized subquery */
Subq_materialization_tracker *materialization_tracker;
protected:
/* Used to trigger on/off conditions that were pushed down to subselect */
bool *pushed_cond_guards;
@ -525,6 +530,7 @@ protected:
left_expr could later be changed to something on the execution arena.
*/
Item *left_expr_orig;
public:
/* Priority of this predicate in the convert-to-semi-join-nest process. */
int sj_convert_priority;
@ -626,7 +632,7 @@ public:
Item_in_subselect(THD *thd_arg, Item * left_expr, st_select_lex *select_lex);
Item_in_subselect(THD *thd_arg):
Item_exists_subselect(thd_arg), left_expr_cache(0), first_execution(TRUE),
in_strategy(SUBS_NOT_TRANSFORMED),
in_strategy(SUBS_NOT_TRANSFORMED), materialization_tracker(NULL),
pushed_cond_guards(NULL), func(NULL), do_not_convert_to_sj(FALSE),
is_jtbm_merged(FALSE), is_jtbm_const_tab(FALSE), upper_item(0),
converted_from_in_predicate(FALSE) {}
@ -778,6 +784,9 @@ public:
{ return left_expr; }
inline Item* left_exp_orig() const
{ return left_expr_orig; }
void init_subq_materialization_tracker(THD *thd);
Subq_materialization_tracker *get_materialization_tracker() const
{ return materialization_tracker; }
friend class Item_ref_null_helper;
friend class Item_is_not_null_test;
@ -1159,6 +1168,15 @@ public:
select_result_interceptor *result,
bool temp= FALSE) override;
bool no_tables() const override;//=>base class
/* Possible execution strategies that can be used to compute hash semi-join.*/
enum exec_strategy {
UNDEFINED= 0,
COMPLETE_MATCH, /* Use regular index lookups. */
PARTIAL_MATCH, /* Use some partial matching strategy. */
PARTIAL_MATCH_MERGE, /* Use partial matching through index merging. */
PARTIAL_MATCH_SCAN, /* Use partial matching through table scan. */
IMPOSSIBLE /* Subquery materialization is not applicable. */
};
protected:
/* The engine used to compute the IN predicate. */
@ -1170,15 +1188,6 @@ protected:
uint count_partial_match_columns;
uint count_null_only_columns;
uint count_columns_with_nulls;
/* Possible execution strategies that can be used to compute hash semi-join.*/
enum exec_strategy {
UNDEFINED,
COMPLETE_MATCH, /* Use regular index lookups. */
PARTIAL_MATCH, /* Use some partial matching strategy. */
PARTIAL_MATCH_MERGE, /* Use partial matching through index merging. */
PARTIAL_MATCH_SCAN, /* Use partial matching through table scan. */
IMPOSSIBLE /* Subquery materialization is not applicable. */
};
/* The chosen execution strategy. Computed after materialization. */
exec_strategy strategy;
exec_strategy get_strategy_using_schema();
@ -1311,6 +1320,7 @@ public:
rownum_t get_max_null_row() { return max_null_row; }
MY_BITMAP * get_null_key() { return &null_key; }
ha_rows get_null_count() { return null_count; }
ha_rows get_key_buff_elements() { return key_buff_elements; }
/*
Get the search key element that corresponds to the i-th key part of this
index.
@ -1548,4 +1558,93 @@ public:
void cleanup() override;
enum_engine_type engine_type() override { return TABLE_SCAN_ENGINE; }
};
/**
@brief Subquery materialization tracker
@details
Used to track various parameters of the materialized subquery execution,
such as the execution strategy, sizes of buffers employed, etc
*/
class Subq_materialization_tracker
{
public:
using Strategy = subselect_hash_sj_engine::exec_strategy;
Subq_materialization_tracker(MEM_ROOT *mem_root)
: exec_strategy(Strategy::UNDEFINED),
partial_match_buffer_size(0),
partial_match_array_sizes(mem_root),
loops_count(0),
index_lookups_count(0),
partial_matches_count(0)
{}
void report_partial_merge_keys(Ordered_key **merge_keys,
uint merge_keys_count);
void report_exec_strategy(Strategy es)
{
exec_strategy= es;
}
void report_partial_match_buffer_size(longlong sz)
{
partial_match_buffer_size= sz;
}
void increment_loops_count()
{
loops_count++;
}
void increment_index_lookups()
{
index_lookups_count++;
}
void increment_partial_matches()
{
partial_matches_count++;
}
void print_json_members(Json_writer *writer) const;
private:
Strategy exec_strategy;
ulonglong partial_match_buffer_size;
Dynamic_array<ha_rows> partial_match_array_sizes;
/* Number of times subquery predicate was evaluated */
ulonglong loops_count;
/*
Number of times we made a lookup in the materialized temptable
(we do this when all parts of left_expr are not NULLs)
*/
ulonglong index_lookups_count;
/*
Number of times we had to check for a partial match (either by
scanning the materialized subquery or by doing a merge)
*/
ulonglong partial_matches_count;
const char *get_exec_strategy() const
{
switch (exec_strategy)
{
case Strategy::UNDEFINED:
return "undefined";
case Strategy::COMPLETE_MATCH:
return "index_lookup";
case Strategy::PARTIAL_MATCH_MERGE:
return "index_lookup;array merge for partial match";
case Strategy::PARTIAL_MATCH_SCAN:
return "index_lookup;full scan for partial match";
default:
return "unsupported";
}
}
};
#endif /* ITEM_SUBSELECT_INCLUDED */

12
sql/sql_array.h
View File

@ -140,12 +140,24 @@ public:
DBUG_ASSERT(idx < array.elements);
return *(((Elem*)array.buffer) + idx);
}
/// Const variant of at(), which cannot change data
const Elem& at(size_t idx) const
{
return *(((Elem*)array.buffer) + idx);
}
Elem& operator[](size_t idx)
{
return at(idx);
}
/// Const variant of operator[]
const Elem& operator[](size_t idx) const
{
return at(idx);
}
/// @returns pointer to first element
Elem *front()
{

55
sql/sql_explain.cc
View File

@ -24,6 +24,7 @@
#include "my_json_writer.h"
#include "opt_range.h"
#include "sql_expression_cache.h"
#include "item_subselect.h"
const char * STR_DELETING_ALL_ROWS= "Deleting all rows";
const char * STR_IMPOSSIBLE_WHERE= "Impossible WHERE";
@ -782,6 +783,18 @@ bool Explain_node::print_explain_json_cache(Json_writer *writer,
}
bool Explain_node::print_explain_json_subq_materialization(Json_writer *writer,
bool is_analyze)
{
if (subq_materialization)
{
subq_materialization->print_explain_json(writer, is_analyze);
return true;
}
return false;
}
Explain_basic_join::~Explain_basic_join()
{
if (join_tabs)
@ -929,6 +942,8 @@ void Explain_select::print_explain_json(Explain_query *query,
Json_writer_nesting_guard guard(writer);
bool started_cache= print_explain_json_cache(writer, is_analyze);
bool started_subq_mat= print_explain_json_subq_materialization(writer,
is_analyze);
if (message ||
select_type == pushed_derived_text ||
@ -1032,6 +1047,8 @@ void Explain_select::print_explain_json(Explain_query *query,
writer->end_object();
}
if (started_subq_mat)
writer->end_object();
if (started_cache)
writer->end_object();
}
@ -2693,3 +2710,41 @@ void Explain_range_checked_fer::print_json(Json_writer *writer,
writer->end_object();
}
}
void Explain_subq_materialization::print_explain_json(Json_writer *writer,
bool is_analyze)
{
writer->add_member("materialization").start_object();
if (is_analyze)
tracker.print_json_members(writer);
}
void Subq_materialization_tracker::print_json_members(Json_writer *writer) const
{
writer->add_member("r_strategy").add_str(get_exec_strategy());
if (loops_count)
writer->add_member("r_loops").add_ull(loops_count);
if (index_lookups_count)
writer->add_member("r_index_lookups").add_ull(index_lookups_count);
if (partial_matches_count)
writer->add_member("r_partial_matches").add_ull(partial_matches_count);
if (partial_match_buffer_size)
{
writer->add_member("r_partial_match_buffer_size").
add_size(partial_match_buffer_size);
}
if (partial_match_array_sizes.elements())
{
writer->add_member("r_partial_match_array_sizes").start_array();
for(size_t i= 0; i < partial_match_array_sizes.elements(); i++)
writer->add_ull(partial_match_array_sizes[i]);
writer->end_array();
}
}

31
sql/sql_explain.h
View File

@ -86,6 +86,7 @@ class Explain_node : public Sql_alloc
public:
Explain_node(MEM_ROOT *root) :
cache_tracker(NULL),
subq_materialization(NULL),
connection_type(EXPLAIN_NODE_OTHER),
children(root)
{}
@ -115,6 +116,12 @@ public:
*/
Expression_cache_tracker* cache_tracker;
/**
If not NULL, this node is a SELECT (or UNION) in a materialized
IN-subquery.
*/
Explain_subq_materialization* subq_materialization;
/*
How this node is connected to its parent.
(NOTE: EXPLAIN_NODE_NON_MERGED_SJ is set very late currently)
@ -143,6 +150,8 @@ public:
void print_explain_json_for_children(Explain_query *query,
Json_writer *writer, bool is_analyze);
bool print_explain_json_cache(Json_writer *writer, bool is_analyze);
bool print_explain_json_subq_materialization(Json_writer *writer,
bool is_analyze);
virtual ~Explain_node() = default;
};
@ -1003,4 +1012,26 @@ public:
};
/*
EXPLAIN data structure for subquery materialization.
All decisions are made at execution time so here we just store the tracker
that has all the info.
*/
class Explain_subq_materialization : public Sql_alloc
{
public:
Explain_subq_materialization(MEM_ROOT *mem_root)
: tracker(mem_root)
{}
Subq_materialization_tracker *get_tracker() { return &tracker; }
void print_explain_json(Json_writer *writer, bool is_analyze);
private:
Subq_materialization_tracker tracker;
};
#endif //SQL_EXPLAIN_INCLUDED

5
sql/sql_select.cc
View File

@ -1729,6 +1729,11 @@ bool JOIN::build_explain()
curr_tab->tracker= tmp->get_using_temporary_read_tracker();
}
}
if (is_in_subquery())
{
Item_in_subselect *subq= unit->item->get_IN_subquery();
subq->init_subq_materialization_tracker(thd);
}
DBUG_RETURN(0);
}