From e62c8777484e647a481b99d8ff40238fbab417d3 Mon Sep 17 00:00:00 2001
From: "timour@mysql.com" <>
Date: Mon, 29 Aug 2005 17:13:42 +0300
Subject: [PATCH] Fix for BUG#12672.

---
 mysql-test/r/group_min_max.result | 20 ++++++++++++++++
 mysql-test/t/group_min_max.test   | 19 +++++++++++++++
 sql/opt_range.cc                  | 40 +++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+)

diff --git a/mysql-test/r/group_min_max.result b/mysql-test/r/group_min_max.result
index 13eb2690e86..5b3e6f30710 100644
--- a/mysql-test/r/group_min_max.result
+++ b/mysql-test/r/group_min_max.result
@@ -1972,6 +1972,26 @@ a
 b
 c
 d
+create table bug12672 (
+pk_col int auto_increment primary key, a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(64) default ' '
+) engine=innodb;
+insert into bug12672 (a1, a2, b, c, d, dummy) select * from t1;
+create index idx12672_0 on bug12672 (a1);
+create index idx12672_1 on bug12672 (a1,a2,b,c);
+create index idx12672_2 on bug12672 (a1,a2,b);
+analyze table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	Table is already up to date
+explain select distinct a1 from bug12672 where pk_col not in (1,2,3,4);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	bug12672	range	PRIMARY	PRIMARY	4	NULL	93	Using where; Using temporary
+select distinct a1 from bug12672 where pk_col not in (1,2,3,4);
+a1
+a
+b
+c
+d
+drop table bug12672;
 drop table t1;
 drop table t2;
 drop table t3;
diff --git a/mysql-test/t/group_min_max.test b/mysql-test/t/group_min_max.test
index 6731be615fd..dd5f8b43248 100644
--- a/mysql-test/t/group_min_max.test
+++ b/mysql-test/t/group_min_max.test
@@ -651,6 +651,25 @@ select a1 from t1 where a2 = 'b' group by a1;
 explain select distinct a1 from t1 where a2 = 'b';
 select distinct a1 from t1 where a2 = 'b';
 
+#
+# Bug #12672: primary key implcitly included in every innodb index
+#
+
+create table bug12672 (
+  pk_col int auto_increment primary key, a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(64) default ' '
+) engine=innodb;
+
+insert into bug12672 (a1, a2, b, c, d, dummy) select * from t1;
+
+create index idx12672_0 on bug12672 (a1);
+create index idx12672_1 on bug12672 (a1,a2,b,c);
+create index idx12672_2 on bug12672 (a1,a2,b);
+analyze table t1;
+
+explain select distinct a1 from bug12672 where pk_col not in (1,2,3,4);
+select distinct a1 from bug12672 where pk_col not in (1,2,3,4);
+
+drop table bug12672;
 
 drop table t1;
 drop table t2;
diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index c1ebfe105b6..d0d06ea52b2 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -7016,6 +7016,7 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree)
   ha_rows cur_quick_prefix_records= 0;
   uint cur_param_idx;
   key_map cur_used_key_parts;
+  uint pk= param->table->s->primary_key;
 
   for (uint cur_index= 0 ; cur_index_info != cur_index_info_end ;
        cur_index_info++, cur_index++)
@@ -7024,6 +7025,45 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree)
     if (!table->used_keys.is_set(cur_index))
       goto next_index;
 
+    /*
+      If the current storage manager is such that it appends the primary key to
+      each index, then the above condition is insufficient to check if the
+      index is covering. In such cases it may happen that some fields are
+      covered by the PK index, but not by the current index. Since we can't
+      use the concatenation of both indexes for index lookup, such an index
+      does not qualify as covering in our case. If this is the case, below
+      we check that all query fields are indeed covered by 'cur_index'.
+    */
+    if (pk < MAX_KEY && cur_index != pk &&
+        (table->file->table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX))
+    {
+      /* For each table field */
+      for (uint i= 0; i < table->s->fields; i++)
+      {
+        Field *cur_field= table->field[i];
+        /*
+          If the field is used in the current query, check that the
+          field is covered by some keypart of the current index.
+        */
+        if (thd->query_id == cur_field->query_id)
+        {
+          bool is_covered= FALSE;
+          KEY_PART_INFO *key_part= cur_index_info->key_part;
+          KEY_PART_INFO *key_part_end= key_part + cur_index_info->key_parts;
+          for (; key_part != key_part_end ; key_part++)
+          {
+            if (key_part->field == cur_field)
+            {
+              is_covered= TRUE;
+              break;
+            }
+          }
+          if (!is_covered)
+            goto next_index;
+        }
+      }
+    }
+
     /*
       Check (GA1) for GROUP BY queries.
     */