MDEV-37723: TPROC-H Query4...: Remove @@new_mode=FIX_DISK_TMPTABLE_COSTS in 12.1

In 12.1, remove the FIX_DISK_TMPTABLE_COSTS flag from @@new_mode.
The new behavior is now always on.

Author: spetrunia

mysql-test/main/costs.result

@@ -145,9 +145,7 @@ from seq_1_to_7000 a, seq_1_to_3 b;
 set
 @save_mhts= @@max_heap_table_size,
 @@max_heap_table_size=16384;
-set @save_new_mode=@@new_mode;
-set new_mode=CONCAT(@@new_mode, ',FIX_DISK_TMPTABLE_COSTS');
-# This should use:  t1, FirstMatch(t2)
+# This should use "t1, FirstMatch(t2)".  Not "t1, SJ-Materialization(t2)".
 explain format=json
 select c, count(*) as dc
 from t1
@@ -198,74 +196,5 @@ EXPLAIN
     }
   }
 }
-SET new_mode = REPLACE(@@new_mode, 'FIX_DISK_TMPTABLE_COSTS', '');
-# This should use: t1, SJ-Materialization(t2)
-explain format=json
-select c, count(*) as dc
-from t1
-where
-b >= date '1993-06-01' and b < date '1993-06-01' + interval '3' month and
-exists (select * from t2 where e = t1.a and g < h)
-group by c;
-EXPLAIN
-{
-  "query_block": {
-    "select_id": 1,
-    "cost": 12.39219425,
-    "filesort": {
-      "sort_key": "t1.c",
-      "temporary_table": {
-        "nested_loop": [
-          {
-            "table": {
-              "table_name": "t1",
-              "access_type": "ALL",
-              "possible_keys": ["PRIMARY", "t1_ix1"],
-              "loops": 1,
-              "rows": 7000,
-              "cost": 1.1518548,
-              "filtered": 100,
-              "attached_condition": "t1.b >= DATE'1993-06-01' and t1.b < <cache>(DATE'1993-06-01' + interval '3' month)"
-            }
-          },
-          {
-            "table": {
-              "table_name": "<subquery2>",
-              "access_type": "eq_ref",
-              "possible_keys": ["distinct_key"],
-              "key": "distinct_key",
-              "key_length": "4",
-              "used_key_parts": ["e"],
-              "ref": ["func"],
-              "rows": 1,
-              "filtered": 100,
-              "materialized": {
-                "unique": 1,
-                "query_block": {
-                  "select_id": 2,
-                  "nested_loop": [
-                    {
-                      "table": {
-                        "table_name": "t2",
-                        "access_type": "ALL",
-                        "possible_keys": ["PRIMARY"],
-                        "loops": 1,
-                        "rows": 21000,
-                        "cost": 3.4338548,
-                        "filtered": 100,
-                        "attached_condition": "t2.g < t2.h"
-                      }
-                    }
-                  ]
-                }
-              }
-            }
-          }
-        ]
-      }
-    }
-  }
-}
-set new_mode=@save_new_mode;
 set max_heap_table_size=@save_mhts;
 drop table t1, t2;

mysql-test/main/costs.test

@@ -141,8 +141,8 @@ set
   @save_mhts= @@max_heap_table_size,
   @@max_heap_table_size=16384;
 
-set @save_new_mode=@@new_mode;
-let $q=
+
+--echo # This should use "t1, FirstMatch(t2)".  Not "t1, SJ-Materialization(t2)".
 explain format=json
 select c, count(*) as dc
 from t1
@@ -151,15 +151,5 @@ where
   exists (select * from t2 where e = t1.a and g < h)
 group by c;
 
-set new_mode=CONCAT(@@new_mode, ',FIX_DISK_TMPTABLE_COSTS');
---echo # This should use:  t1, FirstMatch(t2)
-eval $q;
-
-SET new_mode = REPLACE(@@new_mode, 'FIX_DISK_TMPTABLE_COSTS', '');
-
---echo # This should use: t1, SJ-Materialization(t2)
-eval $q;
-
-set new_mode=@save_new_mode;
 set max_heap_table_size=@save_mhts;
 drop table t1, t2;

mysql-test/main/opt_trace.result

@@ -12172,8 +12172,8 @@ JS
             "org_cost": 1.159965,
             "postjoin_cost": 4.020888502,
             "one_splitting_cost": 5.180853502,
-            "unsplit_postjoin_cost": 32.78652054,
-            "unsplit_cost": 148.7830205,
+            "unsplit_postjoin_cost": 159.1588125,
+            "unsplit_cost": 275.1553125,
             "rows": 100,
             "refills": 5,
             "total_splitting_cost": 25.90426751,

mysql-test/main/subselect3.result

@@ -1167,9 +1167,9 @@ set @@optimizer_switch='firstmatch=off,materialization=off';
 set @@max_heap_table_size= 16384;
 explain select count(*) from t0 A, t0 B, t0 C, t0 D where D.a in (select a from t1 E where a+1 < 10000 + A.a + B.a +C.a+D.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	E	ALL	NULL	NULL	NULL	NULL	5	Start temporary
-1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
+1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	10	
 1	PRIMARY	B	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
+1	PRIMARY	E	ALL	NULL	NULL	NULL	NULL	5	Start temporary; Using join buffer (flat, BNL join)
 1	PRIMARY	C	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	D	ALL	NULL	NULL	NULL	NULL	10	Using where; End temporary; Using join buffer (flat, BNL join)
 flush status;

mysql-test/suite/sys_vars/r/new_mode.result

@@ -7,9 +7,11 @@ SELECT @session_start_value;
 @session_start_value
 
 SET @@global.new_mode = "FIX_DISK_TMPTABLE_COSTS";
+Warnings:
+Warning	4200	The setting 'new_mode=FIX_DISK_TMPTABLE_COSTS' is ignored. It only exists for compatibility with old installations and will be removed in a future release
 SELECT @@global.new_mode;
 @@global.new_mode
-FIX_DISK_TMPTABLE_COSTS
+
 SELECT @@session.new_mode;
 @@session.new_mode
 
@@ -22,17 +24,19 @@ SELECT @@session.new_mode;
 
 SET @@session.new_mode = "FIX_DISK_TMPTABLE_COSTS,TEST_WARNING1";
 Warnings:
+Warning	4200	The setting 'new_mode=FIX_DISK_TMPTABLE_COSTS' is ignored. It only exists for compatibility with old installations and will be removed in a future release
 Warning	4200	The setting 'new_mode=TEST_WARNING1' is ignored. It only exists for compatibility with old installations and will be removed in a future release
 SET @@session.new_mode = "FIX_DISK_TMPTABLE_COSTS,TEST_WARNING1,TEST_WARNING2";
 Warnings:
+Warning	4200	The setting 'new_mode=FIX_DISK_TMPTABLE_COSTS' is ignored. It only exists for compatibility with old installations and will be removed in a future release
 Warning	4200	The setting 'new_mode=TEST_WARNING1' is ignored. It only exists for compatibility with old installations and will be removed in a future release
 Warning	4200	The setting 'new_mode=TEST_WARNING2' is ignored. It only exists for compatibility with old installations and will be removed in a future release
 SET @@session.new_mode = "FIX_DISK_TMPTABLE_COSTS,TEST_WARNING1,TEST_WARNING2,TEST_WARNING3";
 ERROR 42000: Variable 'new_mode' can't be set to the value of 'TEST_WARNING3'
 SET @@session.new_mode = "ALL";
 select @@session.new_mode;
 @@session.new_mode
-FIX_DISK_TMPTABLE_COSTS
+
 SET @@global.new_mode = NULL;
 ERROR 42000: Variable 'new_mode' can't be set to the value of 'NULL'
 SET @@global.new_mode = '';

mysql-test/suite/sys_vars/r/sysvars_server_embedded.result

@@ -2419,7 +2419,7 @@ VARIABLE_COMMENT	Used to introduce new behavior to existing MariaDB versions
 NUMERIC_MIN_VALUE	NULL
 NUMERIC_MAX_VALUE	NULL
 NUMERIC_BLOCK_SIZE	NULL
-ENUM_VALUE_LIST	FIX_DISK_TMPTABLE_COSTS
+ENUM_VALUE_LIST	
 READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	REQUIRED
 VARIABLE_NAME	NOTE_VERBOSITY

mysql-test/suite/sys_vars/r/sysvars_server_notembedded.result

@@ -2639,7 +2639,7 @@ VARIABLE_COMMENT	Used to introduce new behavior to existing MariaDB versions
 NUMERIC_MIN_VALUE	NULL
 NUMERIC_MAX_VALUE	NULL
 NUMERIC_BLOCK_SIZE	NULL
-ENUM_VALUE_LIST	FIX_DISK_TMPTABLE_COSTS
+ENUM_VALUE_LIST	
 READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	REQUIRED
 VARIABLE_NAME	NOTE_VERBOSITY

sql/opt_subselect.cc

@@ -2777,19 +2777,10 @@ get_tmp_table_costs(THD *thd, double row_count, uint row_size, bool blobs_used,
                            tmp_table_optimizer_costs.row_copy_cost :
                            0);
     /* Disk based table */
-    if (TEST_NEW_MODE_FLAG(thd, NEW_MODE_FIX_DISK_TMPTABLE_COSTS))
-    {
-      cost.lookup=         ((tmp_table_optimizer_costs.key_lookup_cost +
-                             tmp_table_optimizer_costs.disk_read_cost *
-                             tmp_table_optimizer_costs.disk_read_ratio) +
-                           row_copy_cost);
-    }
-    else
-    {
-      cost.lookup=         ((tmp_table_optimizer_costs.key_lookup_cost *
-                            tmp_table_optimizer_costs.disk_read_ratio) +
-                           row_copy_cost);
-    }
+    cost.lookup=         ((tmp_table_optimizer_costs.key_lookup_cost +
+                           tmp_table_optimizer_costs.disk_read_cost *
+                           tmp_table_optimizer_costs.disk_read_ratio) +
+                         row_copy_cost);
     /*
       Don't have numbers for cost of writing, assume it's the same as cost
       of reading for lack of a better number.

sql/sql_class.h

@@ -227,14 +227,14 @@ void old_mode_deprecated_warnings(ulonglong v);
   See sys_vars.cc /new_mode_all_names
 */
 
-#define NEW_MODE_FIX_DISK_TMPTABLE_COSTS                               (1 << 0)
-#define NEW_MODE_MAX                                                         1
+#define NEW_MODE_MAX                                                         0
 
 /* Definitions above that have transitioned from new behaviour to default */
 
 #define NOW_DEFAULT                                             -1
 #define NEW_MODE_TEST_WARNING1                               NOW_DEFAULT
 #define NEW_MODE_TEST_WARNING2                               NOW_DEFAULT
+#define NEW_MODE_FIX_DISK_TMPTABLE_COSTS                     NOW_DEFAULT
 
 #define TEST_NEW_MODE_FLAG(thd, flag) \
   (flag == NOW_DEFAULT ? TRUE : thd->variables.new_behavior & flag)

sql/sys_vars.cc

@@ -4182,6 +4182,7 @@ static const char *new_mode_all_names[]=
 
 static int new_mode_hidden_names[] =
 {
+  0,  // FIX_DISK_TMPTABLE_COSTS
   1,  // TEST_WARNING1
   2,  // TEST_WARNING2
   -1  // End of list