bk commit into 4.1 tree (svoj:1.2502) BUG#20357

[Sergey Vojtovich]

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4.1 repository of svoj. When svoj does a push these changes will
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ChangeSet
  1.2502 06/06/16 21:38:36 svoj@stripped +3 -0
  BUG#20357 - Got error 124 from storage engine using MIN and MAX
              functions in queries
  
  Using MAX()/MIN() on table with disabled indexes (by ALTER TABLE)
  results in error 124 (wrong index) from storage engine.
  
  The problem was that optimizer use disabled index to optimize
  MAX()/MIN(). Nromally it must skip disabled index and perform
  table scan.
  
  This patch skips disabled indexes for min/max optimization.

  sql/opt_sum.cc
    1.46 06/06/16 21:38:31 svoj@stripped +6 -1
    Skip disabled indexes for min/max optimization.

  mysql-test/t/myisam.test
    1.46 06/06/16 21:38:31 svoj@stripped +10 -0
    Test case for BUG#20357.

  mysql-test/r/myisam.result
    1.60 06/06/16 21:38:31 svoj@stripped +7 -0
    Test case for BUG#20357.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	svoj
# Host:	may.pils.ru
# Root:	/home/svoj/devel/mysql/BUG20357/mysql-4.1

--- 1.45/sql/opt_sum.cc	2005-09-25 23:22:20 +05:00
+++ 1.46/sql/opt_sum.cc	2006-06-16 21:38:31 +05:00
@@ -679,7 +679,12 @@ static bool find_key_for_maxmin(bool max
          part != part_end ;
          part++, jdx++, key_part_to_use= (key_part_to_use << 1) | 1)
     {
-      if (!(table->file->index_flags(idx, jdx, 0) & HA_READ_ORDER))
+      /*
+        Perform a check if index is not disabled by ALTER TABLE
+        and is usable for min/max function.
+      */
+      if (!table->keys_in_use.is_set(idx) ||
+          !(table->file->index_flags(idx, jdx, 0) & HA_READ_ORDER))
         return 0;
 
       if (field->eq(part->field))

--- 1.59/mysql-test/r/myisam.result	2006-03-10 18:03:00 +04:00
+++ 1.60/mysql-test/r/myisam.result	2006-06-16 21:38:31 +05:00
@@ -748,3 +748,10 @@ select count(id1) from t1 where id2 = 10
 count(id1)
 5
 drop table t1;
+CREATE TABLE t1(a TINYINT, KEY(a)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES(1);
+ALTER TABLE t1 DISABLE KEYS;
+SELECT MAX(a) FROM t1;
+MAX(a)
+1
+DROP TABLE t1;

--- 1.45/mysql-test/t/myisam.test	2006-03-10 18:03:00 +04:00
+++ 1.46/mysql-test/t/myisam.test	2006-06-16 21:38:31 +05:00
@@ -705,4 +705,14 @@ select count(*)   from t1 where id2 = 10
 select count(id1) from t1 where id2 = 10;
 drop table t1;
 
+#
+# BUG##20357 - Got error 124 from storage engine using MIN and MAX functions
+#              in queries
+#
+CREATE TABLE t1(a TINYINT, KEY(a)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES(1);
+ALTER TABLE t1 DISABLE KEYS;
+SELECT MAX(a) FROM t1;
+DROP TABLE t1;
+
 # End of 4.1 tests