From 89493a9980c1afcfffcdd5a46fbe2664f2c070fc Mon Sep 17 00:00:00 2001
From: Sergei Petrunia <sergey@mariadb.com>
Date: Tue, 15 Oct 2024 17:35:27 +0300
Subject: [PATCH] MDEV-34993: fix merge into 10.6: OPTIMIZER_ADJ_FIX_CARD_MULT
 should be ON by default

---
 mysql-test/main/mysqld--help.result                  |  2 +-
 mysql-test/main/secondary_key_costs.result           |  2 +-
 .../main/selectivity_innodb_notembedded.result       | 12 +++++++-----
 mysql-test/main/selectivity_notembedded.result       | 12 +++++++-----
 sql/sql_priv.h                                       |  2 ++
 sql/sys_vars.cc                                      |  2 +-
 6 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/mysql-test/main/mysqld--help.result b/mysql-test/main/mysqld--help.result
index 0e6945f5455..352063ece38 100644
--- a/mysql-test/main/mysqld--help.result
+++ b/mysql-test/main/mysqld--help.result
@@ -1709,7 +1709,7 @@ old-alter-table DEFAULT
 old-mode UTF8_IS_UTF8MB3
 old-passwords FALSE
 old-style-user-limits FALSE
-optimizer-adjust-secondary-key-costs fix_reuse_range_for_ref
+optimizer-adjust-secondary-key-costs fix_reuse_range_for_ref,fix_card_multiplier
 optimizer-join-limit-pref-ratio 0
 optimizer-max-sel-arg-weight 32000
 optimizer-max-sel-args 16000
diff --git a/mysql-test/main/secondary_key_costs.result b/mysql-test/main/secondary_key_costs.result
index 3a5b883068c..09c6fa31cab 100644
--- a/mysql-test/main/secondary_key_costs.result
+++ b/mysql-test/main/secondary_key_costs.result
@@ -82,7 +82,7 @@ json_detailed(json_extract(@trace, '$**.considered_access_paths'))
 drop table t1, name, flag2;
 select @@optimizer_adjust_secondary_key_costs;
 @@optimizer_adjust_secondary_key_costs
-fix_reuse_range_for_ref
+fix_reuse_range_for_ref,fix_card_multiplier
 set @@optimizer_adjust_secondary_key_costs=7;
 select @@optimizer_adjust_secondary_key_costs;
 @@optimizer_adjust_secondary_key_costs
diff --git a/mysql-test/main/selectivity_innodb_notembedded.result b/mysql-test/main/selectivity_innodb_notembedded.result
index 8e7920cb4ee..04450f1b348 100644
--- a/mysql-test/main/selectivity_innodb_notembedded.result
+++ b/mysql-test/main/selectivity_innodb_notembedded.result
@@ -250,7 +250,9 @@ JS
         {
             "index_name": "key1",
             "selectivity_from_index": 0.399,
-            "selectivity_multiplier": 90.9091
+            "selectivity_multiplier": 90.9091,
+            "note": "multiplier too high, clipping",
+            "clipped_multiplier": 2.506265664
         }
     ]
 ]
@@ -266,16 +268,16 @@ JS
         [
             {
                 "access_type": "range",
-                "resulting_rows": 181.3636545,
-                "cost": 1.79769e308,
+                "resulting_rows": 5,
+                "cost": 6.83879845,
                 "chosen": true
             }
         ],
         "chosen_access_method": 
         {
             "type": "range",
-            "records": 181.3636545,
-            "cost": 1.79769e308,
+            "records": 5,
+            "cost": 6.83879845,
             "uses_join_buffering": false
         }
     }
diff --git a/mysql-test/main/selectivity_notembedded.result b/mysql-test/main/selectivity_notembedded.result
index d8dbb80fa59..02d557ca793 100644
--- a/mysql-test/main/selectivity_notembedded.result
+++ b/mysql-test/main/selectivity_notembedded.result
@@ -245,7 +245,9 @@ JS
         {
             "index_name": "key1",
             "selectivity_from_index": 0.391,
-            "selectivity_multiplier": 90.9091
+            "selectivity_multiplier": 90.9091,
+            "note": "multiplier too high, clipping",
+            "clipped_multiplier": 2.557544757
         }
     ]
 ]
@@ -261,16 +263,16 @@ JS
         [
             {
                 "access_type": "range",
-                "resulting_rows": 177.7272905,
-                "cost": 1.79769e308,
+                "resulting_rows": 5,
+                "cost": 6.647684891,
                 "chosen": true
             }
         ],
         "chosen_access_method": 
         {
             "type": "range",
-            "records": 177.7272905,
-            "cost": 1.79769e308,
+            "records": 5,
+            "cost": 6.647684891,
             "uses_join_buffering": false
         }
     }
diff --git a/sql/sql_priv.h b/sql/sql_priv.h
index a15b7bbebfe..251da05b420 100644
--- a/sql/sql_priv.h
+++ b/sql/sql_priv.h
@@ -278,6 +278,8 @@
 #define OPTIMIZER_ADJ_FIX_REUSE_RANGE_FOR_REF (16)
 #define OPTIMIZER_ADJ_FIX_CARD_MULT (32)
 
+#define OPTIMIZER_ADJ_DEFAULT (OPTIMIZER_ADJ_FIX_REUSE_RANGE_FOR_REF | \
+                               OPTIMIZER_ADJ_FIX_CARD_MULT)
 /*
   Replication uses 8 bytes to store SQL_MODE in the binary log. The day you
   use strictly more than 64 bits by adding one more define above, you should
diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index 630726c5cb8..cb35386f883 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -2860,7 +2860,7 @@ static Sys_var_set Sys_optimizer_adjust_secondary_key_costs(
     "This variable will be deleted in MariaDB 11.0 as it is not needed with the "
     "new 11.0 optimizer.",
     SESSION_VAR(optimizer_adjust_secondary_key_costs), CMD_LINE(REQUIRED_ARG),
-    adjust_secondary_key_cost, DEFAULT(OPTIMIZER_ADJ_FIX_REUSE_RANGE_FOR_REF));
+    adjust_secondary_key_cost, DEFAULT(OPTIMIZER_ADJ_DEFAULT));
 
 
 static Sys_var_charptr_fscs Sys_pid_file(