add_key_part modified

4 files changed, 95 insertions, 0 deletions

diff --git a/mysql-test/main/xyz.test b/mysql-test/main/xyz.test
new file mode 100644
index 00000000000..ef98394568f
--- /dev/null
+++ b/mysql-test/main/xyz.test
@@ -0,0 +1,10 @@
+create table t1(a int primary key , b int , c int, unique(b,c));
+insert into t1 values(1,1,1),(2,2,2),(3,3,3),(4,4,4),(5,5,5);
+insert into t1 select a+5, b+5, c+5 from t1;
+insert into t1 select a+10, b+10, c+10 from t1;
+insert into t1 select a+20, b+20, c+20 from t1;
+insert into t1 select a+40, b+40, c+40 from t1;
+ --query_vertical explain select * from t1 where a=34;
+ --query_vertical explain select * from t1 where b=34;
+ --query_vertical explain select * from t1 where c=34;
+drop table t1;
diff --git a/mysql-test/main/xyz_blob.result b/mysql-test/main/xyz_blob.result
new file mode 100644
index 00000000000..e4403b0e169
--- /dev/null
+++ b/mysql-test/main/xyz_blob.result
@@ -0,0 +1,62 @@
+create table t1(a blob unique , b blob , c blob, unique(b,c));
+insert into t1 values(1,1,1),(2,2,2),(3,3,3),(4,4,4),(5,5,5);
+insert into t1 select a+5, b+5, c+5 from t1;
+insert into t1 select a+10, b+10, c+10 from t1;
+insert into t1 select a+20, b+20, c+20 from t1;
+insert into t1 select a+40, b+40, c+40 from t1;
+explain select * from t1 where a="34";;
+id	1
+select_type	SIMPLE
+table	NULL
+type	NULL
+possible_keys	NULL
+key	NULL
+key_len	NULL
+ref	NULL
+rows	NULL
+Extra	Impossible WHERE noticed after reading const tables
+explain select * from t1 where b="34" and c = "34";;
+id	1
+select_type	SIMPLE
+table	t1
+type	ALL
+possible_keys	b
+key	NULL
+key_len	NULL
+ref	NULL
+rows	80
+Extra	Using where
+explain select * from t1 where c="34" and b="34";;
+id	1
+select_type	SIMPLE
+table	t1
+type	ALL
+possible_keys	b
+key	NULL
+key_len	NULL
+ref	NULL
+rows	80
+Extra	Using where
+explain select * from t1 where c="34";;
+id	1
+select_type	SIMPLE
+table	t1
+type	ALL
+possible_keys	NULL
+key	NULL
+key_len	NULL
+ref	NULL
+rows	80
+Extra	Using where
+explain select * from t1 where b="34";;
+id	1
+select_type	SIMPLE
+table	NULL
+type	NULL
+possible_keys	NULL
+key	NULL
+key_len	NULL
+ref	NULL
+rows	NULL
+Extra	Impossible WHERE noticed after reading const tables
+drop table t1;
diff --git a/mysql-test/main/xyz_blob.test b/mysql-test/main/xyz_blob.test
new file mode 100644
index 00000000000..05c5f635ff3
--- /dev/null
+++ b/mysql-test/main/xyz_blob.test
@@ -0,0 +1,12 @@
+create table t1(a blob unique , b blob , c blob, unique(b,c));
+insert into t1 values(1,1,1),(2,2,2),(3,3,3),(4,4,4),(5,5,5);
+insert into t1 select a+5, b+5, c+5 from t1;
+insert into t1 select a+10, b+10, c+10 from t1;
+insert into t1 select a+20, b+20, c+20 from t1;
+insert into t1 select a+40, b+40, c+40 from t1;
+--query_vertical explain select * from t1 where a="34";
+--query_vertical explain select * from t1 where b="34" and c = "34";
+--query_vertical explain select * from t1 where c="34" and b="34";
+--query_vertical explain select * from t1 where c="34";
+--query_vertical explain select * from t1 where b="34";
+drop table t1;
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index c660af38118..0e06ea9a717 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -6058,15 +6058,26 @@ add_key_part(DYNAMIC_ARRAY *keyuse_array, KEY_FIELD *key_field)
 
       KEY *keyinfo= form->key_info+key;
       uint key_parts= form->actual_n_key_parts(keyinfo);
+      if (keyinfo->algorithm == HA_KEY_ALG_LONG_HASH)
+      {
+        re_setup_keyinfo_hash(keyinfo);
+        key_parts= keyinfo->user_defined_key_parts;
+      }
       for (uint part=0 ; part <  key_parts ; part++)
       {
         if (field->eq(form->key_info[key].key_part[part].field) &&
             field->can_optimize_keypart_ref(key_field->cond, key_field->val))
 	{
           if (add_keyuse(keyuse_array, key_field, key, part))
+          {
+            if (keyinfo->algorithm == HA_KEY_ALG_LONG_HASH)
+              setup_keyinfo_hash(keyinfo);
             return TRUE;
+          }
 	}
       }
+      if (keyinfo->algorithm == HA_KEY_ALG_LONG_HASH)
+        setup_keyinfo_hash(keyinfo);
     }
     if (field->hash_join_is_possible() &&
         (key_field->optimize & KEY_OPTIMIZE_EQ) &&