Change SEL_ARG::MAX_SEL_ARGS to a user defined variable optimizer_max_sel_args

This allows a user to to change the default value of MAX_SEL_ARGS (16000)
in the rare case where they neeed more generated SEL_ARGS (as part of
the range optimizer)

mysql-test/main/mysqld--help.result

@@ -716,6 +716,10 @@ The following specify which files/extra groups are read (specified before remain
  --optimizer-max-sel-arg-weight=# 
  The maximum weight of the SEL_ARG graph. Set to 0 for no
  limit
+ --optimizer-max-sel-args=# 
+ The maximum number of SEL_ARG objects created when
+ optimizing a range. If more objects would be needed, the
+ range will not be used by the optimizer.
  --optimizer-prune-level=# 
  Controls the heuristic(s) applied during query
  optimization to prune less-promising partial plans from
@@ -1682,6 +1686,7 @@ old-mode UTF8_IS_UTF8MB3
 old-passwords FALSE
 old-style-user-limits FALSE
 optimizer-max-sel-arg-weight 32000
+optimizer-max-sel-args 16000
 optimizer-prune-level 1
 optimizer-search-depth 62
 optimizer-selectivity-sampling-limit 100

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

@@ -2272,12 +2272,22 @@ NUMERIC_BLOCK_SIZE	1
 ENUM_VALUE_LIST	NULL
 READ_ONLY	YES
 COMMAND_LINE_ARGUMENT	REQUIRED
+VARIABLE_NAME	OPTIMIZER_MAX_SEL_ARGS
+VARIABLE_SCOPE	SESSION
+VARIABLE_TYPE	BIGINT UNSIGNED
+VARIABLE_COMMENT	The maximum number of SEL_ARG objects created when optimizing a range. If more objects would be needed, the range will not be used by the optimizer.
+NUMERIC_MIN_VALUE	0
+NUMERIC_MAX_VALUE	4294967295
+NUMERIC_BLOCK_SIZE	1
+ENUM_VALUE_LIST	NULL
+READ_ONLY	NO
+COMMAND_LINE_ARGUMENT	REQUIRED
 VARIABLE_NAME	OPTIMIZER_MAX_SEL_ARG_WEIGHT
 VARIABLE_SCOPE	SESSION
 VARIABLE_TYPE	BIGINT UNSIGNED
 VARIABLE_COMMENT	The maximum weight of the SEL_ARG graph. Set to 0 for no limit
 NUMERIC_MIN_VALUE	0
-NUMERIC_MAX_VALUE	18446744073709551615
+NUMERIC_MAX_VALUE	4294967295
 NUMERIC_BLOCK_SIZE	1
 ENUM_VALUE_LIST	NULL
 READ_ONLY	NO

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

@@ -2432,12 +2432,22 @@ NUMERIC_BLOCK_SIZE	1
 ENUM_VALUE_LIST	NULL
 READ_ONLY	YES
 COMMAND_LINE_ARGUMENT	REQUIRED
+VARIABLE_NAME	OPTIMIZER_MAX_SEL_ARGS
+VARIABLE_SCOPE	SESSION
+VARIABLE_TYPE	BIGINT UNSIGNED
+VARIABLE_COMMENT	The maximum number of SEL_ARG objects created when optimizing a range. If more objects would be needed, the range will not be used by the optimizer.
+NUMERIC_MIN_VALUE	0
+NUMERIC_MAX_VALUE	4294967295
+NUMERIC_BLOCK_SIZE	1
+ENUM_VALUE_LIST	NULL
+READ_ONLY	NO
+COMMAND_LINE_ARGUMENT	REQUIRED
 VARIABLE_NAME	OPTIMIZER_MAX_SEL_ARG_WEIGHT
 VARIABLE_SCOPE	SESSION
 VARIABLE_TYPE	BIGINT UNSIGNED
 VARIABLE_COMMENT	The maximum weight of the SEL_ARG graph. Set to 0 for no limit
 NUMERIC_MIN_VALUE	0
-NUMERIC_MAX_VALUE	18446744073709551615
+NUMERIC_MAX_VALUE	4294967295
 NUMERIC_BLOCK_SIZE	1
 ENUM_VALUE_LIST	NULL
 READ_ONLY	NO

sql/opt_range.cc

@@ -725,7 +725,8 @@ int SEL_IMERGE::or_sel_tree_with_checks(RANGE_OPT_PARAM *param,
             
             result_keys.set_bit(key_no);
 #ifdef EXTRA_DEBUG
-            if (param->alloced_sel_args < SEL_ARG::MAX_SEL_ARGS)
+            if (param->alloced_sel_args <
+                param->thd->variables.optimizer_max_sel_args)
 	    {
               key1= result->keys[key_no]; 
               (key1)->test_use_count(key1);
@@ -2054,7 +2055,7 @@ SEL_ARG *SEL_ARG::clone(RANGE_OPT_PARAM *param, SEL_ARG *new_parent,
   SEL_ARG *tmp;
 
   /* Bail out if we have already generated too many SEL_ARGs */
-  if (++param->alloced_sel_args > MAX_SEL_ARGS)
+  if (++param->alloced_sel_args > param->thd->variables.optimizer_max_sel_args)
     return 0;
 
   if (type != KEY_RANGE)
@@ -2897,7 +2898,7 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
         if (notnull_cond_tree)
           tree= tree_and(&param, tree, notnull_cond_tree);
         if (thd->trace_started() && 
-            param.alloced_sel_args >= SEL_ARG::MAX_SEL_ARGS)
+            param.alloced_sel_args >= thd->variables.optimizer_max_sel_args)
         {
           Json_writer_object wrapper(thd);
           Json_writer_object obj(thd, "sel_arg_alloc_limit_hit");
@@ -9286,7 +9287,8 @@ int and_range_trees(RANGE_OPT_PARAM *param, SEL_TREE *tree1, SEL_TREE *tree2,
       }
       result_keys.set_bit(key_no);
 #ifdef EXTRA_DEBUG
-      if (param->alloced_sel_args < SEL_ARG::MAX_SEL_ARGS) 
+      if (param->alloced_sel_args <
+          param->thd->variables.optimizer_max_sel_args)
         key->test_use_count(key);
 #endif
     }
@@ -9939,7 +9941,8 @@ and_all_keys(RANGE_OPT_PARAM *param, SEL_ARG *key1, SEL_ARG *key2,
       key1->weight+= (tmp? tmp->weight: 0) - old_weight;
       if (use_count)
 	next->increment_use_count(use_count);
-      if (param->alloced_sel_args > SEL_ARG::MAX_SEL_ARGS)
+      if (param->alloced_sel_args >
+          param->thd->variables.optimizer_max_sel_args)
         break;
     }
     else

sql/opt_range.h

@@ -322,7 +322,7 @@ class SEL_ARG :public Sql_alloc
 #endif
 
   /* See RANGE_OPT_PARAM::alloced_sel_args */
-  enum { MAX_SEL_ARGS = 16000 };
+  enum { DEFAULT_MAX_SEL_ARGS = 16000 };
 
   SEL_ARG() = default;
   SEL_ARG(SEL_ARG &);
@@ -740,7 +740,7 @@ class RANGE_OPT_PARAM
       thd->killed ||
       thd->is_fatal_error ||
       thd->is_error() ||
-      alloced_sel_args > SEL_ARG::MAX_SEL_ARGS;
+      alloced_sel_args > thd->variables.optimizer_max_sel_args;
   }
 };
 

sql/sql_class.h

@@ -751,6 +751,8 @@ typedef struct system_variables
   ulong optimizer_search_depth;
   ulong optimizer_selectivity_sampling_limit;
   ulong optimizer_use_condition_selectivity;
+  ulong optimizer_max_sel_arg_weight;
+  ulong optimizer_max_sel_args;
   ulong use_stat_tables;
   double sample_percentage;
   ulong histogram_size;
@@ -879,7 +881,7 @@ typedef struct system_variables
   uint column_compression_threshold;
   uint column_compression_zlib_level;
   uint in_subquery_conversion_threshold;
-  ulong optimizer_max_sel_arg_weight;
+
   ulonglong max_rowid_filter_size;
 
   vers_asof_timestamp_t vers_asof_timestamp;

sql/sys_vars.cc

@@ -6835,7 +6835,15 @@ static Sys_var_ulong Sys_optimizer_max_sel_arg_weight(
        "optimizer_max_sel_arg_weight",
        "The maximum weight of the SEL_ARG graph. Set to 0 for no limit",
        SESSION_VAR(optimizer_max_sel_arg_weight), CMD_LINE(REQUIRED_ARG),
-       VALID_RANGE(0, ULONG_MAX), DEFAULT(SEL_ARG::MAX_WEIGHT), BLOCK_SIZE(1));
+       VALID_RANGE(0, UINT_MAX), DEFAULT(SEL_ARG::MAX_WEIGHT), BLOCK_SIZE(1));
+
+static Sys_var_ulong Sys_optimizer_max_sel_args(
+       "optimizer_max_sel_args",
+       "The maximum number of SEL_ARG objects created when optimizing a range. "
+       "If more objects would be needed, the range will not be used by the "
+       "optimizer.",
+       SESSION_VAR(optimizer_max_sel_args), CMD_LINE(REQUIRED_ARG),
+       VALID_RANGE(0, UINT_MAX), DEFAULT(SEL_ARG::DEFAULT_MAX_SEL_ARGS), BLOCK_SIZE(1));
 
 static Sys_var_enum Sys_secure_timestamp(
        "secure_timestamp", "Restricts direct setting of a session "