MDEV-23645: Optimizer trace: print conditions after substitute_for_best_equal_field

Print the conditions for WHERE, HAVING, and ON.

mysql-test/main/opt_trace.result

@@ -153,9 +153,14 @@ select * from v1	{
           {
             "best_join_order": ["t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t1.a = 1"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t1.a = 1",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -299,9 +304,14 @@ select * from (select * from t1 where t1.a=1)q	{
           {
             "best_join_order": ["t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t1.a = 1"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t1.a = 1",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -452,9 +462,14 @@ select * from v2	{
                 {
                   "best_join_order": ["t1"]
                 },
+                {
+                  "substitute_best_equal": {
+                    "condition": "WHERE",
+                    "resulting_condition": "t1.a = 1"
+                  }
+                },
                 {
                   "attaching_conditions_to_tables": {
-                    "original_condition": "t1.a = 1",
                     "attached_conditions_computation": [],
                     "attached_conditions_summary": [
                       {
@@ -520,7 +535,6 @@ select * from v2	{
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": null,
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -659,7 +673,6 @@ explain select * from v2	{
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": null,
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -779,7 +792,6 @@ explain select * from v1	{
                 },
                 {
                   "attaching_conditions_to_tables": {
-                    "original_condition": null,
                     "attached_conditions_computation": [],
                     "attached_conditions_summary": [
                       {
@@ -845,7 +857,6 @@ explain select * from v1	{
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": null,
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -1103,9 +1114,14 @@ explain select * from t1,t2 where t1.a=t2.b+2 and t2.a= t1.b	{
           {
             "best_join_order": ["t1", "t2"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t2.a = t1.b and t1.a = t2.b + 2"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t2.a = t1.b and t1.a = t2.b + 2",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -1274,7 +1290,6 @@ EXPLAIN SELECT DISTINCT a FROM t1	{
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": null,
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -1465,9 +1480,14 @@ EXPLAIN SELECT MIN(d) FROM t1 where b=2 and c=3  group by a	{
           {
             "best_join_order": ["t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t1.b = 2 and t1.c = 3"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t1.b = 2 and t1.c = 3",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -1659,9 +1679,14 @@ EXPLAIN SELECT id,MIN(a),MAX(a) FROM t1 WHERE a>=20010104e0 GROUP BY id	{
           {
             "best_join_order": ["t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t1.a >= 20010104e0"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t1.a >= 20010104e0",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -1842,9 +1867,14 @@ EXPLAIN SELECT * FROM t1 WHERE a = 20010104e0 GROUP BY id	{
           {
             "best_join_order": ["t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t1.a = 20010104e0"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t1.a = 20010104e0",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -2120,9 +2150,14 @@ explain  select * from t1 where a=1 and b=2 order by c limit 1	{
           {
             "best_join_order": ["t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t1.a = 1 and t1.b = 2"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t1.a = 1 and t1.b = 2",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -2360,12 +2395,17 @@ select t1.a from t1 left join t2 on t1.a=t2.a	{
           {
             "best_join_order": ["t2", "t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "1"
+            }
+          },
           {
             "condition_on_constant_tables": "1"
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "1",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -2517,12 +2557,24 @@ explain select * from t1 left join t2 on t2.a=t1.a	{
           {
             "best_join_order": ["t1", "t2"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "1"
+            }
+          },
+          {
+            "substitute_best_equal": {
+              "condition": "ON expr",
+              "attached_to": "t2",
+              "resulting_condition": "t2.a = t1.a"
+            }
+          },
           {
             "condition_on_constant_tables": "1"
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "1",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -2675,12 +2727,17 @@ explain select t1.a from t1 left join (t2 join t3 on t2.b=t3.b) on t2.a=t1.a and
           {
             "best_join_order": ["t3", "t2", "t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "1"
+            }
+          },
           {
             "condition_on_constant_tables": "1"
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "1",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -2988,12 +3045,17 @@ explain extended select * from t1 where a in (select pk from t10)	{
           {
             "best_join_order": ["t1", "<subquery2>"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "1"
+            }
+          },
           {
             "condition_on_constant_tables": "1"
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "1",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -3349,9 +3411,14 @@ explain select * from t1 where pk = 2 and a=5 and b=1	{
           {
             "best_join_order": ["t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t1.pk = 2 and t1.a = 5 and t1.b = 1"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t1.pk = 2 and t1.a = 5 and t1.b = 1",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -3475,7 +3542,6 @@ select f1(a) from t1	{
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": null,
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -3573,7 +3639,6 @@ select f2(a) from t1	{
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": null,
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -3611,7 +3676,7 @@ a
 2
 select length(trace) from INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 length(trace)
-2183
+2141
 set optimizer_trace_max_mem_size=100;
 select * from t1;
 a
@@ -3625,7 +3690,7 @@ select * from t1	{
       "join_preparation": {
         "select_id": 1,
         "steps": [
-        	2083	0
+        	2041	0
 set optimizer_trace_max_mem_size=0;
 select * from t1;
 a
@@ -3633,7 +3698,7 @@ a
 2
 select * from INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 QUERY	TRACE	MISSING_BYTES_BEYOND_MAX_MEM_SIZE	INSUFFICIENT_PRIVILEGES
-select * from t1		2183	0
+select * from t1		2141	0
 drop table t1;
 set optimizer_trace='enabled=off';
 set @@optimizer_trace_max_mem_size= @save_optimizer_trace_max_mem_size;
@@ -4041,9 +4106,14 @@ explain delete t0,t1 from t0, t1 where t0.a=t1.a and t1.a<3	{
           {
             "best_join_order": ["t0", "t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t1.a = t0.a and t0.a < 3"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t1.a = t0.a and t0.a < 3",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -4180,7 +4250,6 @@ explain select * from (select rand() from t1)q	{
                 },
                 {
                   "attaching_conditions_to_tables": {
-                    "original_condition": null,
                     "attached_conditions_computation": [],
                     "attached_conditions_summary": [
                       {
@@ -4246,7 +4315,6 @@ explain select * from (select rand() from t1)q	{
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": null,
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -4686,12 +4754,17 @@ explain select * from t1 where a in (select t_inner_1.a from t1 t_inner_1, t1 t_
           {
             "best_join_order": ["t1", "<subquery2>"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "1"
+            }
+          },
           {
             "condition_on_constant_tables": "1"
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "1",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -6255,9 +6328,14 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4)	{
               "t_inner_3"
             ]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t_inner_1.a = t_outer_1.a and t_inner_3.a = t_outer_2.a"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t_inner_1.a = t_outer_1.a and t_inner_3.a = t_outer_2.a",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -7332,12 +7410,17 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4)	{
               "<subquery3>"
             ]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "1"
+            }
+          },
           {
             "condition_on_constant_tables": "1"
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "1",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -8644,7 +8727,6 @@ select count(*) from seq_1_to_10000000	{
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": null,
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -8832,4 +8914,98 @@ S
     "cause": "no predicate for first keypart"
 }
 drop table t1,t2,t3;
+#
+# MDEV-23645: Optimizer trace: print conditions after substitute_for_best_equal_field
+#
+create table t1 (a int, b int, c int);
+insert into t1 values (1,1,1),(2,2,2);
+create table t2 as select * from t1;
+insert into t2 select * from t2;
+create table t3 as select * from t2;
+insert into t3 select * from t3;
+# Check how HAVING is printed
+explain 
+select 
+a,b, count(*)
+from t1
+where a=3
+group by b,b
+having a+b < 10;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	Using where; Using temporary; Using filesort
+select
+json_detailed(json_extract(trace, '$**.substitute_best_equal'))
+from
+information_schema.optimizer_trace;
+json_detailed(json_extract(trace, '$**.substitute_best_equal'))
+[
+    
+    {
+        "condition": "WHERE",
+        "resulting_condition": "t1.a = 3"
+    },
+    
+    {
+        "condition": "HAVING",
+        "resulting_condition": "t1.a + t1.b < 10"
+    }
+]
+# Check ON expression
+explain 
+select 
+*
+from t1 left join t2 on t2.a=t1.a and t2.a<3 
+where 
+t1.b > 5555;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+select
+json_detailed(json_extract(trace, '$**.substitute_best_equal'))
+from
+information_schema.optimizer_trace;
+json_detailed(json_extract(trace, '$**.substitute_best_equal'))
+[
+    
+    {
+        "condition": "WHERE",
+        "resulting_condition": "t1.b > 5555"
+    },
+    
+    {
+        "condition": "ON expr",
+        "attached_to": "t2",
+        "resulting_condition": "t2.a = t1.a and t1.a < 3"
+    }
+]
+# Check nested ON expression
+explain 
+select 
+*
+from t1 left join (t2,t3) on t2.a=t1.a and t3.a=t2.a and t3.a + t2.a <1000
+where 
+t1.b > 5555;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	8	Using where; Using join buffer (incremental, BNL join)
+select
+json_detailed(json_extract(trace, '$**.substitute_best_equal'))
+from
+information_schema.optimizer_trace;
+json_detailed(json_extract(trace, '$**.substitute_best_equal'))
+[
+    
+    {
+        "condition": "WHERE",
+        "resulting_condition": "t1.b > 5555"
+    },
+    
+    {
+        "condition": "ON expr",
+        "attached_to": "t2",
+        "resulting_condition": "t2.a = t1.a and t3.a = t1.a and t1.a + t1.a < 1000"
+    }
+]
+drop table t1,t2,t3;
 set optimizer_trace='enabled=off';

mysql-test/main/opt_trace.test

@@ -727,4 +727,57 @@ select
 
 drop table t1,t2,t3;
 
+--echo #
+--echo # MDEV-23645: Optimizer trace: print conditions after substitute_for_best_equal_field
+--echo #
+create table t1 (a int, b int, c int);
+insert into t1 values (1,1,1),(2,2,2);
+
+create table t2 as select * from t1;
+insert into t2 select * from t2;
+
+create table t3 as select * from t2;
+insert into t3 select * from t3;
+
+--echo # Check how HAVING is printed
+explain 
+select 
+  a,b, count(*)
+from t1
+where a=3
+group by b,b
+having a+b < 10;
+
+select
+  json_detailed(json_extract(trace, '$**.substitute_best_equal'))
+from
+  information_schema.optimizer_trace;
+
+--echo # Check ON expression
+explain 
+select 
+ *
+from t1 left join t2 on t2.a=t1.a and t2.a<3 
+where 
+  t1.b > 5555;
+
+select
+  json_detailed(json_extract(trace, '$**.substitute_best_equal'))
+from
+  information_schema.optimizer_trace;
+
+--echo # Check nested ON expression
+explain 
+select 
+ *
+from t1 left join (t2,t3) on t2.a=t1.a and t3.a=t2.a and t3.a + t2.a <1000
+where 
+  t1.b > 5555;
+select
+  json_detailed(json_extract(trace, '$**.substitute_best_equal'))
+from
+  information_schema.optimizer_trace;
+
+drop table t1,t2,t3;
+
 set optimizer_trace='enabled=off';

mysql-test/main/opt_trace_index_merge.result

@@ -229,9 +229,14 @@ explain select * from t1 where a=1 or b=1	{
           {
             "best_join_order": ["t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t1.a = 1 or t1.b = 1"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t1.a = 1 or t1.b = 1",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {

mysql-test/main/opt_trace_index_merge_innodb.result

@@ -234,9 +234,14 @@ explain select * from t1 where pk1 != 0  and key1 = 1	{
           {
             "best_join_order": ["t1"]
           },
+          {
+            "substitute_best_equal": {
+              "condition": "WHERE",
+              "resulting_condition": "t1.key1 = 1 and t1.pk1 <> 0"
+            }
+          },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": "t1.key1 = 1 and t1.pk1 <> 0",
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {

mysql-test/main/opt_trace_security.result

@@ -117,7 +117,6 @@ select * from db1.t1	{
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": null,
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {
@@ -240,7 +239,6 @@ select * from db1.v1	{
           },
           {
             "attaching_conditions_to_tables": {
-              "original_condition": null,
               "attached_conditions_computation": [],
               "attached_conditions_summary": [
                 {

sql/opt_trace.cc

@@ -595,6 +595,18 @@ void Json_writer::add_table_name(const TABLE *table)
 }
 
 
+void trace_condition(THD * thd, const char *name, const char *transform_type,
+                    Item *item, const char *table_name)
+{
+  Json_writer_object trace_wrapper(thd);
+  Json_writer_object trace_cond(thd, transform_type);
+  trace_cond.add("condition", name);
+  if (table_name)
+    trace_cond.add("attached_to", table_name);
+  trace_cond.add("resulting_condition", item);
+}
+
+
 void add_table_scan_values_to_trace(THD *thd, JOIN_TAB *tab)
 {
   DBUG_ASSERT(thd->trace_started());

sql/opt_trace.h

@@ -108,6 +108,10 @@ void print_final_join_order(JOIN *join);
 void print_best_access_for_table(THD *thd, POSITION *pos,
                                  enum join_type type);
 
+void trace_condition(THD * thd, const char *name, const char *transform_type,
+                    Item *item, const char *table_name= nullptr);
+
+
 /*
   Security related (need to add a proper comment here)
 */

sql/sql_select.cc

@@ -2408,6 +2408,10 @@ int JOIN::optimize_stage2()
       DBUG_RETURN(1);
     }
     conds->update_used_tables();
+
+    if (unlikely(thd->trace_started()))
+      trace_condition(thd, "WHERE", "substitute_best_equal", conds);
+
     DBUG_EXECUTE("where",
                  print_where(conds,
                              "after substitute_best_equal",
@@ -2424,7 +2428,12 @@ int JOIN::optimize_stage2()
       DBUG_RETURN(1);
     }
     if (having)
+    {
       having->update_used_tables();
+      if (unlikely(thd->trace_started()))
+        trace_condition(thd, "HAVING", "substitute_best_equal", having);
+    }
+
     DBUG_EXECUTE("having",
                  print_where(having,
                              "after substitute_best_equal",
@@ -2451,6 +2460,11 @@ int JOIN::optimize_stage2()
         DBUG_RETURN(1);
       }
       (*tab->on_expr_ref)->update_used_tables();
+      if (unlikely(thd->trace_started()))
+      {
+        trace_condition(thd, "ON expr", "substitute_best_equal",
+                        (*tab->on_expr_ref), tab->table->alias.c_ptr());
+      }
     }
   }
 
@@ -11479,7 +11493,6 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
     */
     Json_writer_object trace_wrapper(thd);
     Json_writer_object trace_conditions(thd, "attaching_conditions_to_tables");
-    trace_conditions.add("original_condition", cond);
     Json_writer_array trace_attached_comp(thd,
                                         "attached_conditions_computation");
     uint i;