bk commit into 4.1 tree (ramil:1.2539) BUG#20732

[ramil]

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ChangeSet@stripped, 2006-09-28 11:43:40+05:00, ramil@stripped +3 -0
  Fix for bug #20732: Partial index and long sjis search with '>' fails sometimes
  
  We miss some records sometimes using RANGE method if we have 
  partial key segments.
  Example:
    create table t1(a char(2), key(a(1)));                                          
    insert into t1 values ('a'), ('xx');                                            
    select a from t1 where a > 'x';                                                 
  We call index_read() passing 'x' key and HA_READ_AFTER_KEY flag
  in the handler::read_range_first() wich is wrong because we have 
  a partial key segment for the field and might miss records like 'xx'.
  
  Fix: don't use open segments in such a case.

  mysql-test/r/range.result@stripped, 2006-09-28 11:43:34+05:00, ramil@stripped +10 -0
    Fix for bug #20732: Partial index and long sjis search with '>' fails sometimes
      - test result

  mysql-test/t/range.test@stripped, 2006-09-28 11:43:34+05:00, ramil@stripped +11 -1
    Fix for bug #20732: Partial index and long sjis search with '>' fails sometimes
      - test case

  sql/opt_range.cc@stripped, 2006-09-28 11:43:34+05:00, ramil@stripped +10 -8
    Fix for bug #20732: Partial index and long sjis search with '>' fails sometimes
      - check if we have a partial key segment for a Item_func::GT_FUNC; 
        if so, don't set NEAR_MIN flag in order to use HA_READ_KEY_OR_NEXT 
        instead of HA_READ_AFTER_KEY.
    
        Note: we cannot use HA_PART_KEY_SEG here as it's also set for fields            
        that can be NULL (see sql/table.cc).

# 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:	ramil
# Host:	myoffice.izhnet.ru
# Root:	/usr/home/ram/work/bug20732/my41-bug20732

--- 1.147/sql/opt_range.cc	2006-09-28 11:43:49 +05:00
+++ 1.148/sql/opt_range.cc	2006-09-28 11:43:49 +05:00
@@ -396,9 +396,9 @@ typedef struct st_qsel_param {
 static SEL_TREE * get_mm_parts(PARAM *param,COND *cond_func,Field *field,
 			       Item_func::Functype type,Item *value,
 			       Item_result cmp_type);
-static SEL_ARG *get_mm_leaf(PARAM *param,COND *cond_func,Field *field,
-			    KEY_PART *key_part,
-			    Item_func::Functype type,Item *value);
+static SEL_ARG *get_mm_leaf(PARAM *param, COND *cond_func, Field *orig_field,
+                            Field *field, KEY_PART *key_part,
+			    Item_func::Functype type, Item *value);
 static SEL_TREE *get_mm_tree(PARAM *param,COND *cond);
 static ha_rows check_quick_select(PARAM *param,uint index,SEL_ARG *key_tree);
 static ha_rows check_quick_keys(PARAM *param,uint index,SEL_ARG *key_tree,
@@ -1146,8 +1146,8 @@ get_mm_parts(PARAM *param, COND *cond_fu
 	DBUG_RETURN(0);				// OOM
       if (!value || !(value->used_tables() & ~param->read_tables))
       {
-	sel_arg=get_mm_leaf(param,cond_func,
-			    key_part->field,key_part,type,value);
+	sel_arg= get_mm_leaf(param, cond_func, field, key_part->field,
+                             key_part, type, value);
 	if (!sel_arg)
 	  continue;
 	if (sel_arg->type == SEL_ARG::IMPOSSIBLE)
@@ -1182,8 +1182,8 @@ get_mm_parts(PARAM *param, COND *cond_fu
 
 
 static SEL_ARG *
-get_mm_leaf(PARAM *param, COND *conf_func, Field *field, KEY_PART *key_part,
-	    Item_func::Functype type,Item *value)
+get_mm_leaf(PARAM *param, COND *conf_func, Field *orig_field, Field *field, 
+            KEY_PART *key_part, Item_func::Functype type, Item *value)
 {
   uint maybe_null=(uint) field->real_maybe_null(), copies;
   uint field_length=field->pack_length()+maybe_null;
@@ -1398,7 +1398,9 @@ get_mm_leaf(PARAM *param, COND *conf_fun
     }
     break;
   case Item_func::GT_FUNC:
-    if (field_is_equal_to_item(field,value))
+    /* Don't use open ranges for partial key segments */
+    if (field_is_equal_to_item(field,value) && 
+        (orig_field->key_length() == key_part->length))
       tree->min_flag=NEAR_MIN;
     /* fall through */
   case Item_func::GE_FUNC:

--- 1.35/mysql-test/r/range.result	2006-09-28 11:43:49 +05:00
+++ 1.36/mysql-test/r/range.result	2006-09-28 11:43:49 +05:00
@@ -649,3 +649,13 @@ OR ((pk4 =1) AND (((pk1 IN ( 7, 2, 1 )))
 pk1	pk2	pk3	pk4	filler
 2621	2635	1000015	0	filler
 drop table t1, t2;
+create table t1(a char(2), key(a(1)));
+insert into t1 values ('x'), ('xx');
+explain select a from t1 where a > 'x';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	a	a	2	NULL	2	Using where
+select a from t1 where a > 'x';
+a
+xx
+drop table t1;
+End of 4.1 tests

--- 1.31/mysql-test/t/range.test	2006-09-28 11:43:49 +05:00
+++ 1.32/mysql-test/t/range.test	2006-09-28 11:43:49 +05:00
@@ -510,4 +510,14 @@ OR ((pk4 =1) AND (((pk1 IN ( 7, 2, 1 )))
 ) AND (pk3 >=1000000);
 drop table t1, t2;
 
-# End of 4.1 tests
+#
+# Bug #20732: Partial index and long sjis search with '>' fails sometimes
+#
+
+create table t1(a char(2), key(a(1)));
+insert into t1 values ('x'), ('xx');
+explain select a from t1 where a > 'x';
+select a from t1 where a > 'x';
+drop table t1;
+
+--echo End of 4.1 tests