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ANALYZE FORMAT=JSON: better output and tests

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- Print r_loops
- Always print r_* members. Print NULL values if no scans took place
- Added testcases.
This commit is contained in:
Sergei Petrunia
2014-11-29 03:07:24 +03:00
parent 0b5d989c89
commit e235bb864d
6 changed files with 270 additions and 8 deletions
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177
mysql-test/r/analyze_format_json.result Normal file
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@@ -0,0 +1,177 @@
drop table if exists t0,t1,t2,t3;
create table t0 (a int);
INSERT INTO t0 VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
# r_filtered=30%, because 3 rows match: 0,1,2
analyze format=json select * from t0 where a<3;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t0",
"access_type": "ALL",
"r_loops": 1,
"rows": 10,
"r_rows": 10,
"filtered": 100,
"r_filtered": 30,
"attached_condition": "(t0.a < 3)"
}
}
}
create table t1 (a int, b int, c int, key(a));
insert into t1 select A.a*10 + B.a, A.a*10 + B.a, A.a*10 + B.a from t0 A, t0 B;
analyze
select * from t0, t1 where t1.a=t0.a and t0.a > 9;
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
1 SIMPLE t0 ALL NULL NULL NULL NULL 10 10 100.00 0.00 Using where
1 SIMPLE t1 ref a a 5 test.t0.a 1 NULL 100.00 NULL
analyze format=json
select * from t0, t1 where t1.a=t0.a and t0.a > 9;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t0",
"access_type": "ALL",
"r_loops": 1,
"rows": 10,
"r_rows": 10,
"filtered": 100,
"r_filtered": 0,
"attached_condition": "((t0.a > 9) and (t0.a is not null))"
},
"table": {
"table_name": "t1",
"access_type": "ref",
"possible_keys": ["a"],
"key": "a",
"key_length": "5",
"used_key_parts": ["a"],
"ref": ["test.t0.a"],
"r_loops": 0,
"rows": 1,
"r_rows": null,
"filtered": 100,
"r_filtered": null
}
}
}
analyze
select * from t0, t1 where t1.a=t0.a and t1.b<4;
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
1 SIMPLE t0 ALL NULL NULL NULL NULL 10 10 100.00 100.00 Using where
1 SIMPLE t1 ref a a 5 test.t0.a 1 1 100.00 40.00 Using where
analyze format=json
select * from t0, t1 where t1.a=t0.a and t1.b<4;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t0",
"access_type": "ALL",
"r_loops": 1,
"rows": 10,
"r_rows": 10,
"filtered": 100,
"r_filtered": 100,
"attached_condition": "(t0.a is not null)"
},
"table": {
"table_name": "t1",
"access_type": "ref",
"possible_keys": ["a"],
"key": "a",
"key_length": "5",
"used_key_parts": ["a"],
"ref": ["test.t0.a"],
"r_loops": 10,
"rows": 1,
"r_rows": 1,
"filtered": 100,
"r_filtered": 40,
"attached_condition": "(t1.b < 4)"
}
}
}
analyze
select * from t1 A, t1 B where A.b<2 and B.b>5;
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
1 SIMPLE A ALL NULL NULL NULL NULL 100 100 100.00 2.00 Using where
1 SIMPLE B ALL NULL NULL NULL NULL 100 100 100.00 94.00 Using where; Using join buffer (flat, BNL join)
analyze format=json
select * from t1 A, t1 B where A.b<20 and B.b<60;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "A",
"access_type": "ALL",
"r_loops": 1,
"rows": 100,
"r_rows": 100,
"filtered": 100,
"r_filtered": 20,
"attached_condition": "(A.b < 20)"
},
"block-nl-join": {
"table": {
"table_name": "B",
"access_type": "ALL",
"r_loops": 1,
"rows": 100,
"r_rows": 100,
"filtered": 100,
"r_filtered": 60
},
"buffer_type": "flat",
"join_type": "BNL",
"r_filtered": 100
}
}
}
analyze format=json
select * from t1 A, t1 B where A.b<20 and B.b<60 and A.c > B.c;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "A",
"access_type": "ALL",
"r_loops": 1,
"rows": 100,
"r_rows": 100,
"filtered": 100,
"r_filtered": 20,
"attached_condition": "(A.b < 20)"
},
"block-nl-join": {
"table": {
"table_name": "B",
"access_type": "ALL",
"r_loops": 1,
"rows": 100,
"r_rows": 100,
"filtered": 100,
"r_filtered": 60,
"attached_condition": "(B.b < 60)"
},
"buffer_type": "flat",
"join_type": "BNL",
"attached_condition": "(A.c > B.c)",
"r_filtered": 15.833
}
}
}
select count(*) from t1 A, t1 B where A.b<20 and B.b<60;
count(*)
1200
select count(*) from t1 A, t1 B where A.b<20 and B.b<60 and A.c > B.c;
count(*)
190
drop table t1;
drop table t0;

38
mysql-test/t/analyze_format_json.test Normal file
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@@ -0,0 +1,38 @@
#
# Tests for "ANALYZE FORMAT=JSON $statement" syntax
#
--disable_warnings
drop table if exists t0,t1,t2,t3;
--enable_warnings
create table t0 (a int);
INSERT INTO t0 VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
--echo # r_filtered=30%, because 3 rows match: 0,1,2
analyze format=json select * from t0 where a<3;
create table t1 (a int, b int, c int, key(a));
insert into t1 select A.a*10 + B.a, A.a*10 + B.a, A.a*10 + B.a from t0 A, t0 B;
analyze
select * from t0, t1 where t1.a=t0.a and t0.a > 9;
analyze format=json
select * from t0, t1 where t1.a=t0.a and t0.a > 9;
analyze
select * from t0, t1 where t1.a=t0.a and t1.b<4;
analyze format=json
select * from t0, t1 where t1.a=t0.a and t1.b<4;
analyze
select * from t1 A, t1 B where A.b<2 and B.b>5;
analyze format=json
select * from t1 A, t1 B where A.b<20 and B.b<60;
analyze format=json
select * from t1 A, t1 B where A.b<20 and B.b<60 and A.c > B.c;
drop table t1;
drop table t0;

6
sql/my_json_writer.cc
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@@ -131,6 +131,12 @@ void Json_writer::add_bool(bool val)
}
void Json_writer::add_null()
{
add_unquoted_str("null");
}
void Json_writer::add_unquoted_str(const char* str)
{
if (fmt_helper.on_add_str(str))

1
sql/my_json_writer.h
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@@ -99,6 +99,7 @@ public:
void add_ll(longlong val);
void add_double(double val);
void add_bool(bool val);
void add_null();
private:
void add_unquoted_str(const char* val);

42
sql/sql_explain.cc
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@@ -815,10 +815,14 @@ void Explain_index_use::set_pseudo_key(MEM_ROOT *root, const char* key_name_arg)
}
/*
Given r_filtered% from join buffer condition and join condition, produce a
combined r_filtered% number. This is needed for tabular EXPLAIN output which
has only one cell for r_filtered value.
*/
double Explain_table_access::get_r_filtered()
{
//psergey-todo: modify this to produce separate filtered% for both parts of
//WHERE.
double r_filtered= tracker.get_filtered_after_where();
if (bka_type.is_using_jbuf())
r_filtered *= jbuf_tracker.get_filtered_after_where();
@@ -1156,15 +1160,27 @@ void Explain_table_access::print_explain_json(Explain_query *query,
writer->end_array();
}
/* r_loops (not present in tabular output) */
if (is_analyze)
{
writer->add_member("r_loops").add_ll(tracker.get_loops());
}
/* `rows` */
if (rows_set)
writer->add_member("rows").add_ll(rows);
/* `r_rows` */
if (is_analyze && tracker.has_scans())
if (is_analyze)
{
writer->add_member("r_rows");
if (tracker.has_scans())
{
ha_rows avg_rows= tracker.get_avg_rows();
writer->add_member("r_rows").add_ll(avg_rows);
writer->add_ll(avg_rows);
}
else
writer->add_null();
}
/* `filtered` */
@@ -1173,7 +1189,13 @@ void Explain_table_access::print_explain_json(Explain_query *query,
/* `r_filtered` */
if (is_analyze)
writer->add_member("r_filtered").add_double(get_r_filtered());
{
writer->add_member("r_filtered");
if (tracker.has_scans())
writer->add_double(tracker.get_filtered_after_where()*100.0);
else
writer->add_null();
}
for (int i=0; i < (int)extra_tags.elements(); i++)
{
@@ -1193,6 +1215,16 @@ void Explain_table_access::print_explain_json(Explain_query *query,
writer->add_member("attached_condition");
write_item(writer, where_cond);
}
if (is_analyze)
{
//writer->add_member("r_loops").add_ll(jbuf_tracker.get_loops());
writer->add_member("r_filtered");
if (jbuf_tracker.has_scans())
writer->add_double(jbuf_tracker.get_filtered_after_where()*100.0);
else
writer->add_null();
}
}
if (derived_select_number)

10
sql/sql_explain.h
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@@ -22,8 +22,13 @@ public:
};
/*
A class for collecting read statistics.
The idea is that we run several scans. Each scans gets rows, and then filters
some of them out. We count scans, rows, and rows left after filtering.
*/
/* Data structures for ANALYZE */
class Table_access_tracker
{
public:
@@ -38,6 +43,7 @@ public:
ha_rows r_rows_after_where; /* Rows after applying attached part of WHERE */
bool has_scans() { return (r_scans != 0); }
ha_rows get_loops() { return r_scans; }
ha_rows get_avg_rows()
{
return r_scans ? (ha_rows)rint((double) r_rows / r_scans): 0;
@@ -612,6 +618,8 @@ public:
bool is_analyze);
/* ANALYZE members */
/* Tracker for reading the table */
Table_access_tracker tracker;
Table_access_tracker jbuf_tracker;