--- mysql-5.1.44-orig/sql/mysql_priv.h	2010-02-04 20:39:50.000000000 +0900
+++ mysql-5.1.44/sql/mysql_priv.h	2010-03-09 08:36:48.000000000 +0900
@@ -2159,7 +2159,11 @@ bool is_table_name_exclusively_locked_by
                                                      TABLE_LIST *table_list);
 bool is_table_name_exclusively_locked_by_this_thread(THD *thd, uchar *key,
                                                      int key_length);
-
+/* filesort.cc */
+uint sortlength(THD *thd, SORT_FIELD *sortorder, uint s_length,
+                bool *multi_byte_charset);
+bool check_heapsort_cond(ulong sort_length, ha_rows max_rows, 
+                         ha_rows table_records, ulong sortbuf_size);
 
 /* old unireg functions */
 
--- mysql-5.1.44-orig/sql/sql_select.cc	2010-02-04 20:39:53.000000000 +0900
+++ mysql-5.1.44/sql/sql_select.cc	2010-03-09 08:36:48.000000000 +0900
@@ -16096,6 +16096,43 @@ void JOIN::clear()
   }
 }
 
+
+/* Doing Top-N in-memory heapsort if the following conditions are met.
+  1. LIMIT clause is used (max_rows should be smaller than records)
+  2. All N sort keys fit within sort buffer (less than half)
+  3. max_rows is much smaller than records (less than half)
+*/
+bool check_heapsort_cond(ulong sort_length, ha_rows max_rows, 
+                         ha_rows table_records, ulong sortbuf_size)
+{
+  if (sort_length * max_rows * 2 < sortbuf_size && 
+      table_records > max_rows * 2 )
+    return true;
+  else
+    return false;
+}
+
+
+static bool check_heapsort_cond(THD *thd, JOIN *join, TABLE *table)
+{
+  bool multi_byte_charset;
+  uint length=0;
+  for (ORDER *ord= join->order; ord; ord= ord->next)
+    length++;
+  join->sortorder= 
+  make_unireg_sortorder(join->order, &length, join->sortorder); 
+
+  ulong sort_length= sortlength(thd, join->sortorder, length, &multi_byte_charset);
+  ha_rows max_rows= join->select_limit;
+  ha_rows records= table->file->estimate_rows_upper_bound();
+  ulong memavl= thd->variables.sortbuff_size;
+  if (check_heapsort_cond(sort_length, max_rows, records, memavl))
+    return true;
+  else
+    return false;
+}
+
+
 /**
   EXPLAIN handling.
 
@@ -16519,7 +16556,10 @@ static void select_describe(JOIN *join, 
 	if (need_order)
 	{
 	  need_order=0;
-	  extra.append(STRING_WITH_LEN("; Using filesort"));
+          if (check_heapsort_cond(thd, join, table))
+            extra.append(STRING_WITH_LEN("; Using top-N in-memory sort"));
+          else
+            extra.append(STRING_WITH_LEN("; Using filesort"));
 	}
 	if (distinct & test_all_bits(used_tables,thd->used_tables))
 	  extra.append(STRING_WITH_LEN("; Distinct"));
--- mysql-5.1.44-orig/sql/filesort.cc	2010-02-04 20:38:54.000000000 +0900
+++ mysql-5.1.44/sql/filesort.cc	2010-03-09 08:40:21.000000000 +0900
@@ -45,7 +45,8 @@ static uchar *read_buffpek_from_file(IO_
                                      uchar *buf);
 static ha_rows find_all_keys(SORTPARAM *param,SQL_SELECT *select,
 			     uchar * *sort_keys, IO_CACHE *buffer_file,
-			     IO_CACHE *tempfile,IO_CACHE *indexfile);
+			     IO_CACHE *tempfile,IO_CACHE *indexfile,
+                             bool heapsort);
 static int write_keys(SORTPARAM *param,uchar * *sort_keys,
 		      uint count, IO_CACHE *buffer_file, IO_CACHE *tempfile);
 static void make_sortkey(SORTPARAM *param,uchar *to, uchar *ref_pos);
@@ -57,12 +58,14 @@ static int merge_index(SORTPARAM *param,
 static bool save_index(SORTPARAM *param,uchar **sort_keys, uint count, 
                        FILESORT_INFO *table_sort);
 static uint suffix_length(ulong string_length);
-static uint sortlength(THD *thd, SORT_FIELD *sortorder, uint s_length,
-		       bool *multi_byte_charset);
 static SORT_ADDON_FIELD *get_addon_fields(THD *thd, Field **ptabfield,
                                           uint sortlength, uint *plength);
 static void unpack_addon_fields(struct st_sort_addon_field *addon_field,
                                 uchar *buff);
+static void heap_queue_insert(uchar ** queue, ha_rows queue_size, 
+                              uchar* current_key, uint sort_length);
+static void heap_queue_poll_insert(uchar ** queue, ha_rows queue_size, 
+                                   uchar* current_key, uint sort_length);
 /**
   Sort a table.
   Creates a set of pointers that can be used to read the rows
@@ -104,6 +107,7 @@ ha_rows filesort(THD *thd, TABLE *table,
                  bool sort_positions, ha_rows *examined_rows)
 {
   int error;
+  bool heapsort=false;
   ulong memavl, min_sort_memory;
   uint maxbuffer;
   BUFFPEK *buffpek;
@@ -147,8 +151,35 @@ ha_rows filesort(THD *thd, TABLE *table,
   param.ref_length= table->file->ref_length;
   param.addon_field= 0;
   param.addon_length= 0;
+
+  param.max_rows= max_rows;
+#ifdef CAN_TRUST_RANGE
+  if (select && select->quick && select->quick->records > 0L)
+  {
+    records=min((ha_rows) (select->quick->records*2+EXTRA_RECORDS*2),
+                table->file->stats.records)+EXTRA_RECORDS;
+    selected_records_file=0;
+  }
+  else
+#endif
+  {
+    records= table->file->estimate_rows_upper_bound();
+    /*
+      If number of records is not known, use as much of sort buffer 
+      as possible. 
+    */
+    if (records == HA_POS_ERROR)
+      records--;  // we use 'records+1' below.
+    selected_records_file= 0;
+  }
+  memavl= thd->variables.sortbuff_size;
+
+  if (check_heapsort_cond(param.sort_length, param.max_rows,
+      records, memavl))
+    heapsort= true;
+
   if (!(table->file->ha_table_flags() & HA_FAST_KEY_READ) &&
-      !table->fulltext_searched && !sort_positions)
+      !table->fulltext_searched && !sort_positions && !heapsort)
   {
     /* 
       Get the descriptors of all fields whose values are appended 
@@ -180,7 +211,6 @@ ha_rows filesort(THD *thd, TABLE *table,
     param.sort_length+= param.ref_length;
   }
   param.rec_length= param.sort_length+param.addon_length;
-  param.max_rows= max_rows;
 
   if (select && select->quick)
   {
@@ -190,31 +220,11 @@ ha_rows filesort(THD *thd, TABLE *table,
   {
     status_var_increment(thd->status_var.filesort_scan_count);
   }
-#ifdef CAN_TRUST_RANGE
-  if (select && select->quick && select->quick->records > 0L)
-  {
-    records=min((ha_rows) (select->quick->records*2+EXTRA_RECORDS*2),
-		table->file->stats.records)+EXTRA_RECORDS;
-    selected_records_file=0;
-  }
-  else
-#endif
-  {
-    records= table->file->estimate_rows_upper_bound();
-    /*
-      If number of records is not known, use as much of sort buffer 
-      as possible. 
-    */
-    if (records == HA_POS_ERROR)
-      records--;  // we use 'records+1' below.
-    selected_records_file= 0;
-  }
 
   if (multi_byte_charset &&
       !(param.tmp_buffer= (char*) my_malloc(param.sort_length,MYF(MY_WME))))
     goto err;
 
-  memavl= thd->variables.sortbuff_size;
   min_sort_memory= max(MIN_SORT_MEMORY, param.sort_length*MERGEBUFF2);
   while (memavl >= min_sort_memory)
   {
@@ -243,7 +253,7 @@ ha_rows filesort(THD *thd, TABLE *table,
   param.sort_form= table;
   param.end=(param.local_sortorder=sortorder)+s_length;
   if ((records=find_all_keys(&param,select,sort_keys, &buffpek_pointers,
-			     &tempfile, selected_records_file)) ==
+			     &tempfile, selected_records_file, heapsort)) ==
       HA_POS_ERROR)
     goto err;
   maxbuffer= (uint) (my_b_tell(&buffpek_pointers)/sizeof(*buffpek));
@@ -463,6 +473,54 @@ static void dbug_print_record(TABLE *tab
 }
 #endif 
 
+
+/* Shift-up */
+static void heap_queue_insert(uchar ** queue, ha_rows queue_size, 
+                              uchar* current_key, uint sort_length)
+{
+  ha_rows j= queue_size;
+  qsort2_cmp cmp= get_ptr_compare(sort_length);
+  while (j > 0) 
+  {
+    ha_rows  i= (j - 1) >> 1; 
+    if (cmp((void*)&sort_length, &current_key, queue+i) <= 0)
+      break;
+    memcpy(queue[j],queue[i], sort_length);
+    j= i;
+  }
+  memcpy(queue[j], current_key, sort_length);
+}
+
+
+/* Shift-down */ 
+static void heap_queue_poll_insert(uchar ** queue, ha_rows queue_size, 
+                                   uchar* current_key, uint sort_length)
+{
+  ha_rows n= queue_size;
+  qsort2_cmp cmp= get_ptr_compare(sort_length);
+
+  if (cmp((void*)&sort_length, &current_key, queue+0) >= 0)
+    return;
+
+  memcpy(queue[0], current_key, sort_length);
+  ha_rows i= 0;
+
+  for (;;)
+  {
+    ha_rows  j = 2 * i + 1;
+    if (j >= n)
+      break;
+    if (j + 1 < n &&
+        cmp((void*)&sort_length,queue+j, queue+j+1) < 0 )
+      j++;
+    if (cmp((void*)&sort_length, &current_key, queue+j) >= 0)
+      break;
+    memcpy(queue[i], queue[j], sort_length);
+    i= j;
+  }
+  memcpy(queue[i], current_key, sort_length);
+}
+
 /**
   Search after sort_keys and write them into tempfile.
   All produced sequences are guaranteed to be non-empty.
@@ -503,7 +561,8 @@ static void dbug_print_record(TABLE *tab
 static ha_rows find_all_keys(SORTPARAM *param, SQL_SELECT *select,
 			     uchar **sort_keys,
 			     IO_CACHE *buffpek_pointers,
-			     IO_CACHE *tempfile, IO_CACHE *indexfile)
+			     IO_CACHE *tempfile, IO_CACHE *indexfile,
+                             bool heapsort)
 {
   int error,flag,quick_select;
   uint idx,indexpos,ref_length;
@@ -519,6 +578,11 @@ static ha_rows find_all_keys(SORTPARAM *
                      (select ? select->quick ? "ranges" : "where":
                       "every row")));
 
+  uint heap_queue_size=0;
+  ha_rows heap_queue_limit= param->max_rows;
+  uchar* current_key= NULL;
+  if (heapsort)
+    current_key= (uchar*)my_malloc(param->sort_length, MYF(MY_WME));
   idx=indexpos=0;
   error=quick_select=0;
   sort_form=param->sort_form;
@@ -608,14 +672,34 @@ static ha_rows find_all_keys(SORTPARAM *
       param->examined_rows++;
     if (error == 0 && (!select || select->skip_record() == 0))
     {
-      if (idx == param->keys)
+      if (idx == param->keys && !heapsort)
+      {
+        if (write_keys(param,sort_keys,idx,buffpek_pointers,tempfile))
+          DBUG_RETURN(HA_POS_ERROR);
+        idx=0;
+        indexpos++;
+      }
+
+      if (!heapsort)
+        make_sortkey(param,sort_keys[idx++],ref_pos);
+      else
       {
-	if (write_keys(param,sort_keys,idx,buffpek_pointers,tempfile))
-	  DBUG_RETURN(HA_POS_ERROR);
-	idx=0;
-	indexpos++;
+        make_sortkey(param,current_key,ref_pos);
+
+        /* Adding an entry to the heap */
+        if (heap_queue_size < heap_queue_limit)
+        {
+          heap_queue_insert(sort_keys, heap_queue_size, current_key, 
+                            param->sort_length);
+          heap_queue_size++;
+        } 
+        else
+        {
+          /* Heap size is full, so exchanging with the smallest (largest) one */
+          heap_queue_poll_insert(sort_keys, heap_queue_size, current_key, 
+                                 param->sort_length);
+        }
       }
-      make_sortkey(param,sort_keys[idx++],ref_pos);
     }
     else
       file->unlock_row();
@@ -630,6 +714,11 @@ static ha_rows find_all_keys(SORTPARAM *
       file->ha_rnd_end();
   }
 
+  if (heapsort){
+    idx= heap_queue_size;
+    my_free((uchar*) current_key,MYF(0));
+  }
+
   if (thd->is_error())
     DBUG_RETURN(HA_POS_ERROR);
   
@@ -1431,7 +1520,7 @@ static uint suffix_length(ulong string_l
     Total length of sort buffer in bytes
 */
 
-static uint
+uint
 sortlength(THD *thd, SORT_FIELD *sortorder, uint s_length,
            bool *multi_byte_charset)
 {
--- /dev/null	2010-02-23 00:55:49.298867748 +0900
+++ mysql-5.1.44/mysql-test/t/heapsort.test	2010-03-09 08:36:48.000000000 +0900
@@ -0,0 +1,101 @@
+create table t2 (c1 int, c2 int default 0, c3 varchar(10) default 'abc', c4 int default 1 );
+insert into t2 values(1,10,'a',100),(2,20,'b',200),(3,30,'c',300),(4,40,'d',400),(5,50,'e',500),(6,60,'f',600),(7,70,'g',700),(8,80,'h',800),(9,90,'i',900),(10,100,'j',1000);
+
+# integer sort
+explain select * from t2 order by c1 limit 5; 
+explain select * from t2 order by c1 limit 15; 
+select * from t2 order by c1 limit 5; 
+select * from t2 order by c1 desc limit 5; 
+select * from t2 order by c1 limit 2, 4; 
+
+# string sort
+explain select * from t2 order by c3 limit 5; 
+explain select * from t2 order by c3 limit 15; 
+select * from t2 order by c3 limit 5; 
+select * from t2 order by c3 desc limit 5; 
+select * from t2 order by c3 limit 2, 4; 
+
+truncate table t2;
+insert into t2 values(50,10,'a',100),(40,20,'b',200),(100,30,'c',300),(90,40,'d',400),(10,50,'e',500),(20,60,'f',600),(70,70,'g',700),(80,80,'h',800),(30,90,'i',900),(60,100,'j',1000);
+# unordered integer sort
+select * from t2 order by c1 limit 5; 
+select * from t2 order by c1 desc limit 5; 
+select * from t2 order by c1 limit 2, 4; 
+
+select * from t2 order by c1 limit 10; 
+select * from t2 order by c1 limit 100; 
+select * from t2 order by c1 limit 2, 4; 
+
+select * from t2 order by c1;
+
+drop table t2;
+
+create table s1 (c1 int, c2 int, c3 int, c4 varchar(100) , c5 datetime, primary key(c1));
+
+delimiter //;
+create procedure sp1(IN count INTEGER)
+BEGIN
+ DECLARE done INTEGER DEFAULT 0;
+ DECLARE i INTEGER DEFAULT 1;
+ WHILE done != 1 DO
+ insert into s1 values (i, count-i, i%1000, "abcdefghij", "2009-01-01 11:11:11");
+  SET i = i + 1;
+  IF i > count THEN
+   SET done = 1;
+  END IF;
+ END WHILE;
+END;
+//
+delimiter ;//
+
+call sp1(100000);
+drop procedure sp1;
+
+
+select * from s1 order by c1 limit 0, 10; 
+select * from s1 order by c1 limit 100, 10; 
+select * from s1 order by c1 limit 1000, 10; 
+select * from s1 order by c1 limit 10000, 10; 
+select * from s1 order by c1 limit 100000, 10; 
+
+
+select * from s1 order by c2 limit 0, 10; 
+select * from s1 order by c2 limit 100, 10; 
+select * from s1 order by c2 limit 1000, 10; 
+select * from s1 order by c2 limit 10000, 10; 
+select * from s1 order by c2 limit 100000, 10; 
+
+
+select * from s1 order by c1 desc limit 0, 10; 
+select * from s1 order by c1 desc limit 100, 10; 
+select * from s1 order by c1 desc limit 1000, 10; 
+select * from s1 order by c1 desc limit 10000, 10; 
+select * from s1 order by c1 desc limit 100000, 10; 
+
+select * from s1 order by c2 desc limit 0, 10; 
+select * from s1 order by c2 desc limit 100, 10; 
+select * from s1 order by c2 desc limit 1000, 10; 
+select * from s1 order by c2 desc limit 10000, 10; 
+select * from s1 order by c2 desc limit 100000, 10; 
+
+select * from s1 order by c3,c2 limit 0, 10; 
+select * from s1 order by c3,c2 limit 100, 10; 
+select * from s1 order by c3,c2 limit 1000, 10; 
+select * from s1 order by c3,c2 limit 10000, 10; 
+select * from s1 order by c3,c2 limit 100000, 10; 
+
+select * from s1 order by c3,c1 desc limit 0, 10; 
+select * from s1 order by c3,c1 desc limit 100, 10; 
+select * from s1 order by c3,c1 desc limit 1000, 10; 
+select * from s1 order by c3,c1 desc limit 10000, 10; 
+select * from s1 order by c3,c1 desc limit 100000, 10; 
+
+select a.* from s1 a, (select c1, c3 from s1 order by c3,c1 limit 0, 10) b where a.c1 = b.c1;
+select a.* from s1 a, (select c1, c3 from s1 order by c3,c1 limit 100, 10) b where a.c1 = b.c1;
+select a.* from s1 a, (select c1, c3 from s1 order by c3,c1 limit 1000, 10) b where a.c1 = b.c1;
+select a.* from s1 a, (select c1, c3 from s1 order by c3,c1 limit 10000, 10) b where a.c1 = b.c1;
+select a.* from s1 a, (select c1, c3 from s1 order by c3,c1 limit 100000, 10) b where a.c1 = b.c1;
+
+select * from s1 order by c1 desc, c2, c3 limit 0, 10; 
+
+drop table s1;
--- /dev/null	2010-02-23 00:55:49.298867748 +0900
+++ mysql-5.1.44/mysql-test/r/heapsort.result	2010-03-09 08:36:48.000000000 +0900
@@ -0,0 +1,498 @@
+create table t2 (c1 int, c2 int default 0, c3 varchar(10) default 'abc', c4 int default 1 );
+insert into t2 values(1,10,'a',100),(2,20,'b',200),(3,30,'c',300),(4,40,'d',400),(5,50,'e',500),(6,60,'f',600),(7,70,'g',700),(8,80,'h',800),(9,90,'i',900),(10,100,'j',1000);
+explain select * from t2 order by c1 limit 5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using top-N in-memory sort
+explain select * from t2 order by c1 limit 15;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using filesort
+select * from t2 order by c1 limit 5;
+c1	c2	c3	c4
+1	10	a	100
+2	20	b	200
+3	30	c	300
+4	40	d	400
+5	50	e	500
+select * from t2 order by c1 desc limit 5;
+c1	c2	c3	c4
+10	100	j	1000
+9	90	i	900
+8	80	h	800
+7	70	g	700
+6	60	f	600
+select * from t2 order by c1 limit 2, 4;
+c1	c2	c3	c4
+3	30	c	300
+4	40	d	400
+5	50	e	500
+6	60	f	600
+explain select * from t2 order by c3 limit 5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using top-N in-memory sort
+explain select * from t2 order by c3 limit 15;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using filesort
+select * from t2 order by c3 limit 5;
+c1	c2	c3	c4
+1	10	a	100
+2	20	b	200
+3	30	c	300
+4	40	d	400
+5	50	e	500
+select * from t2 order by c3 desc limit 5;
+c1	c2	c3	c4
+10	100	j	1000
+9	90	i	900
+8	80	h	800
+7	70	g	700
+6	60	f	600
+select * from t2 order by c3 limit 2, 4;
+c1	c2	c3	c4
+3	30	c	300
+4	40	d	400
+5	50	e	500
+6	60	f	600
+truncate table t2;
+insert into t2 values(50,10,'a',100),(40,20,'b',200),(100,30,'c',300),(90,40,'d',400),(10,50,'e',500),(20,60,'f',600),(70,70,'g',700),(80,80,'h',800),(30,90,'i',900),(60,100,'j',1000);
+select * from t2 order by c1 limit 5;
+c1	c2	c3	c4
+10	50	e	500
+20	60	f	600
+30	90	i	900
+40	20	b	200
+50	10	a	100
+select * from t2 order by c1 desc limit 5;
+c1	c2	c3	c4
+100	30	c	300
+90	40	d	400
+80	80	h	800
+70	70	g	700
+60	100	j	1000
+select * from t2 order by c1 limit 2, 4;
+c1	c2	c3	c4
+30	90	i	900
+40	20	b	200
+50	10	a	100
+60	100	j	1000
+select * from t2 order by c1 limit 10;
+c1	c2	c3	c4
+10	50	e	500
+20	60	f	600
+30	90	i	900
+40	20	b	200
+50	10	a	100
+60	100	j	1000
+70	70	g	700
+80	80	h	800
+90	40	d	400
+100	30	c	300
+select * from t2 order by c1 limit 100;
+c1	c2	c3	c4
+10	50	e	500
+20	60	f	600
+30	90	i	900
+40	20	b	200
+50	10	a	100
+60	100	j	1000
+70	70	g	700
+80	80	h	800
+90	40	d	400
+100	30	c	300
+select * from t2 order by c1 limit 2, 4;
+c1	c2	c3	c4
+30	90	i	900
+40	20	b	200
+50	10	a	100
+60	100	j	1000
+select * from t2 order by c1;
+c1	c2	c3	c4
+10	50	e	500
+20	60	f	600
+30	90	i	900
+40	20	b	200
+50	10	a	100
+60	100	j	1000
+70	70	g	700
+80	80	h	800
+90	40	d	400
+100	30	c	300
+drop table t2;
+create table s1 (c1 int, c2 int, c3 int, c4 varchar(100) , c5 datetime, primary key(c1));
+create procedure sp1(IN count INTEGER)
+BEGIN
+DECLARE done INTEGER DEFAULT 0;
+DECLARE i INTEGER DEFAULT 1;
+WHILE done != 1 DO
+insert into s1 values (i, count-i, i%1000, "abcdefghij", "2009-01-01 11:11:11");
+SET i = i + 1;
+IF i > count THEN
+SET done = 1;
+END IF;
+END WHILE;
+END;
+//
+call sp1(100000);
+drop procedure sp1;
+select * from s1 order by c1 limit 0, 10;
+c1	c2	c3	c4	c5
+1	99999	1	abcdefghij	2009-01-01 11:11:11
+2	99998	2	abcdefghij	2009-01-01 11:11:11
+3	99997	3	abcdefghij	2009-01-01 11:11:11
+4	99996	4	abcdefghij	2009-01-01 11:11:11
+5	99995	5	abcdefghij	2009-01-01 11:11:11
+6	99994	6	abcdefghij	2009-01-01 11:11:11
+7	99993	7	abcdefghij	2009-01-01 11:11:11
+8	99992	8	abcdefghij	2009-01-01 11:11:11
+9	99991	9	abcdefghij	2009-01-01 11:11:11
+10	99990	10	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c1 limit 100, 10;
+c1	c2	c3	c4	c5
+101	99899	101	abcdefghij	2009-01-01 11:11:11
+102	99898	102	abcdefghij	2009-01-01 11:11:11
+103	99897	103	abcdefghij	2009-01-01 11:11:11
+104	99896	104	abcdefghij	2009-01-01 11:11:11
+105	99895	105	abcdefghij	2009-01-01 11:11:11
+106	99894	106	abcdefghij	2009-01-01 11:11:11
+107	99893	107	abcdefghij	2009-01-01 11:11:11
+108	99892	108	abcdefghij	2009-01-01 11:11:11
+109	99891	109	abcdefghij	2009-01-01 11:11:11
+110	99890	110	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c1 limit 1000, 10;
+c1	c2	c3	c4	c5
+1001	98999	1	abcdefghij	2009-01-01 11:11:11
+1002	98998	2	abcdefghij	2009-01-01 11:11:11
+1003	98997	3	abcdefghij	2009-01-01 11:11:11
+1004	98996	4	abcdefghij	2009-01-01 11:11:11
+1005	98995	5	abcdefghij	2009-01-01 11:11:11
+1006	98994	6	abcdefghij	2009-01-01 11:11:11
+1007	98993	7	abcdefghij	2009-01-01 11:11:11
+1008	98992	8	abcdefghij	2009-01-01 11:11:11
+1009	98991	9	abcdefghij	2009-01-01 11:11:11
+1010	98990	10	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c1 limit 10000, 10;
+c1	c2	c3	c4	c5
+10001	89999	1	abcdefghij	2009-01-01 11:11:11
+10002	89998	2	abcdefghij	2009-01-01 11:11:11
+10003	89997	3	abcdefghij	2009-01-01 11:11:11
+10004	89996	4	abcdefghij	2009-01-01 11:11:11
+10005	89995	5	abcdefghij	2009-01-01 11:11:11
+10006	89994	6	abcdefghij	2009-01-01 11:11:11
+10007	89993	7	abcdefghij	2009-01-01 11:11:11
+10008	89992	8	abcdefghij	2009-01-01 11:11:11
+10009	89991	9	abcdefghij	2009-01-01 11:11:11
+10010	89990	10	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c1 limit 100000, 10;
+c1	c2	c3	c4	c5
+select * from s1 order by c2 limit 0, 10;
+c1	c2	c3	c4	c5
+100000	0	0	abcdefghij	2009-01-01 11:11:11
+99999	1	999	abcdefghij	2009-01-01 11:11:11
+99998	2	998	abcdefghij	2009-01-01 11:11:11
+99997	3	997	abcdefghij	2009-01-01 11:11:11
+99996	4	996	abcdefghij	2009-01-01 11:11:11
+99995	5	995	abcdefghij	2009-01-01 11:11:11
+99994	6	994	abcdefghij	2009-01-01 11:11:11
+99993	7	993	abcdefghij	2009-01-01 11:11:11
+99992	8	992	abcdefghij	2009-01-01 11:11:11
+99991	9	991	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c2 limit 100, 10;
+c1	c2	c3	c4	c5
+99900	100	900	abcdefghij	2009-01-01 11:11:11
+99899	101	899	abcdefghij	2009-01-01 11:11:11
+99898	102	898	abcdefghij	2009-01-01 11:11:11
+99897	103	897	abcdefghij	2009-01-01 11:11:11
+99896	104	896	abcdefghij	2009-01-01 11:11:11
+99895	105	895	abcdefghij	2009-01-01 11:11:11
+99894	106	894	abcdefghij	2009-01-01 11:11:11
+99893	107	893	abcdefghij	2009-01-01 11:11:11
+99892	108	892	abcdefghij	2009-01-01 11:11:11
+99891	109	891	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c2 limit 1000, 10;
+c1	c2	c3	c4	c5
+99000	1000	0	abcdefghij	2009-01-01 11:11:11
+98999	1001	999	abcdefghij	2009-01-01 11:11:11
+98998	1002	998	abcdefghij	2009-01-01 11:11:11
+98997	1003	997	abcdefghij	2009-01-01 11:11:11
+98996	1004	996	abcdefghij	2009-01-01 11:11:11
+98995	1005	995	abcdefghij	2009-01-01 11:11:11
+98994	1006	994	abcdefghij	2009-01-01 11:11:11
+98993	1007	993	abcdefghij	2009-01-01 11:11:11
+98992	1008	992	abcdefghij	2009-01-01 11:11:11
+98991	1009	991	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c2 limit 10000, 10;
+c1	c2	c3	c4	c5
+90000	10000	0	abcdefghij	2009-01-01 11:11:11
+89999	10001	999	abcdefghij	2009-01-01 11:11:11
+89998	10002	998	abcdefghij	2009-01-01 11:11:11
+89997	10003	997	abcdefghij	2009-01-01 11:11:11
+89996	10004	996	abcdefghij	2009-01-01 11:11:11
+89995	10005	995	abcdefghij	2009-01-01 11:11:11
+89994	10006	994	abcdefghij	2009-01-01 11:11:11
+89993	10007	993	abcdefghij	2009-01-01 11:11:11
+89992	10008	992	abcdefghij	2009-01-01 11:11:11
+89991	10009	991	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c2 limit 100000, 10;
+c1	c2	c3	c4	c5
+select * from s1 order by c1 desc limit 0, 10;
+c1	c2	c3	c4	c5
+100000	0	0	abcdefghij	2009-01-01 11:11:11
+99999	1	999	abcdefghij	2009-01-01 11:11:11
+99998	2	998	abcdefghij	2009-01-01 11:11:11
+99997	3	997	abcdefghij	2009-01-01 11:11:11
+99996	4	996	abcdefghij	2009-01-01 11:11:11
+99995	5	995	abcdefghij	2009-01-01 11:11:11
+99994	6	994	abcdefghij	2009-01-01 11:11:11
+99993	7	993	abcdefghij	2009-01-01 11:11:11
+99992	8	992	abcdefghij	2009-01-01 11:11:11
+99991	9	991	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c1 desc limit 100, 10;
+c1	c2	c3	c4	c5
+99900	100	900	abcdefghij	2009-01-01 11:11:11
+99899	101	899	abcdefghij	2009-01-01 11:11:11
+99898	102	898	abcdefghij	2009-01-01 11:11:11
+99897	103	897	abcdefghij	2009-01-01 11:11:11
+99896	104	896	abcdefghij	2009-01-01 11:11:11
+99895	105	895	abcdefghij	2009-01-01 11:11:11
+99894	106	894	abcdefghij	2009-01-01 11:11:11
+99893	107	893	abcdefghij	2009-01-01 11:11:11
+99892	108	892	abcdefghij	2009-01-01 11:11:11
+99891	109	891	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c1 desc limit 1000, 10;
+c1	c2	c3	c4	c5
+99000	1000	0	abcdefghij	2009-01-01 11:11:11
+98999	1001	999	abcdefghij	2009-01-01 11:11:11
+98998	1002	998	abcdefghij	2009-01-01 11:11:11
+98997	1003	997	abcdefghij	2009-01-01 11:11:11
+98996	1004	996	abcdefghij	2009-01-01 11:11:11
+98995	1005	995	abcdefghij	2009-01-01 11:11:11
+98994	1006	994	abcdefghij	2009-01-01 11:11:11
+98993	1007	993	abcdefghij	2009-01-01 11:11:11
+98992	1008	992	abcdefghij	2009-01-01 11:11:11
+98991	1009	991	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c1 desc limit 10000, 10;
+c1	c2	c3	c4	c5
+90000	10000	0	abcdefghij	2009-01-01 11:11:11
+89999	10001	999	abcdefghij	2009-01-01 11:11:11
+89998	10002	998	abcdefghij	2009-01-01 11:11:11
+89997	10003	997	abcdefghij	2009-01-01 11:11:11
+89996	10004	996	abcdefghij	2009-01-01 11:11:11
+89995	10005	995	abcdefghij	2009-01-01 11:11:11
+89994	10006	994	abcdefghij	2009-01-01 11:11:11
+89993	10007	993	abcdefghij	2009-01-01 11:11:11
+89992	10008	992	abcdefghij	2009-01-01 11:11:11
+89991	10009	991	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c1 desc limit 100000, 10;
+c1	c2	c3	c4	c5
+select * from s1 order by c2 desc limit 0, 10;
+c1	c2	c3	c4	c5
+1	99999	1	abcdefghij	2009-01-01 11:11:11
+2	99998	2	abcdefghij	2009-01-01 11:11:11
+3	99997	3	abcdefghij	2009-01-01 11:11:11
+4	99996	4	abcdefghij	2009-01-01 11:11:11
+5	99995	5	abcdefghij	2009-01-01 11:11:11
+6	99994	6	abcdefghij	2009-01-01 11:11:11
+7	99993	7	abcdefghij	2009-01-01 11:11:11
+8	99992	8	abcdefghij	2009-01-01 11:11:11
+9	99991	9	abcdefghij	2009-01-01 11:11:11
+10	99990	10	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c2 desc limit 100, 10;
+c1	c2	c3	c4	c5
+101	99899	101	abcdefghij	2009-01-01 11:11:11
+102	99898	102	abcdefghij	2009-01-01 11:11:11
+103	99897	103	abcdefghij	2009-01-01 11:11:11
+104	99896	104	abcdefghij	2009-01-01 11:11:11
+105	99895	105	abcdefghij	2009-01-01 11:11:11
+106	99894	106	abcdefghij	2009-01-01 11:11:11
+107	99893	107	abcdefghij	2009-01-01 11:11:11
+108	99892	108	abcdefghij	2009-01-01 11:11:11
+109	99891	109	abcdefghij	2009-01-01 11:11:11
+110	99890	110	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c2 desc limit 1000, 10;
+c1	c2	c3	c4	c5
+1001	98999	1	abcdefghij	2009-01-01 11:11:11
+1002	98998	2	abcdefghij	2009-01-01 11:11:11
+1003	98997	3	abcdefghij	2009-01-01 11:11:11
+1004	98996	4	abcdefghij	2009-01-01 11:11:11
+1005	98995	5	abcdefghij	2009-01-01 11:11:11
+1006	98994	6	abcdefghij	2009-01-01 11:11:11
+1007	98993	7	abcdefghij	2009-01-01 11:11:11
+1008	98992	8	abcdefghij	2009-01-01 11:11:11
+1009	98991	9	abcdefghij	2009-01-01 11:11:11
+1010	98990	10	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c2 desc limit 10000, 10;
+c1	c2	c3	c4	c5
+10001	89999	1	abcdefghij	2009-01-01 11:11:11
+10002	89998	2	abcdefghij	2009-01-01 11:11:11
+10003	89997	3	abcdefghij	2009-01-01 11:11:11
+10004	89996	4	abcdefghij	2009-01-01 11:11:11
+10005	89995	5	abcdefghij	2009-01-01 11:11:11
+10006	89994	6	abcdefghij	2009-01-01 11:11:11
+10007	89993	7	abcdefghij	2009-01-01 11:11:11
+10008	89992	8	abcdefghij	2009-01-01 11:11:11
+10009	89991	9	abcdefghij	2009-01-01 11:11:11
+10010	89990	10	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c2 desc limit 100000, 10;
+c1	c2	c3	c4	c5
+select * from s1 order by c3,c2 limit 0, 10;
+c1	c2	c3	c4	c5
+100000	0	0	abcdefghij	2009-01-01 11:11:11
+99000	1000	0	abcdefghij	2009-01-01 11:11:11
+98000	2000	0	abcdefghij	2009-01-01 11:11:11
+97000	3000	0	abcdefghij	2009-01-01 11:11:11
+96000	4000	0	abcdefghij	2009-01-01 11:11:11
+95000	5000	0	abcdefghij	2009-01-01 11:11:11
+94000	6000	0	abcdefghij	2009-01-01 11:11:11
+93000	7000	0	abcdefghij	2009-01-01 11:11:11
+92000	8000	0	abcdefghij	2009-01-01 11:11:11
+91000	9000	0	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c3,c2 limit 100, 10;
+c1	c2	c3	c4	c5
+99001	999	1	abcdefghij	2009-01-01 11:11:11
+98001	1999	1	abcdefghij	2009-01-01 11:11:11
+97001	2999	1	abcdefghij	2009-01-01 11:11:11
+96001	3999	1	abcdefghij	2009-01-01 11:11:11
+95001	4999	1	abcdefghij	2009-01-01 11:11:11
+94001	5999	1	abcdefghij	2009-01-01 11:11:11
+93001	6999	1	abcdefghij	2009-01-01 11:11:11
+92001	7999	1	abcdefghij	2009-01-01 11:11:11
+91001	8999	1	abcdefghij	2009-01-01 11:11:11
+90001	9999	1	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c3,c2 limit 1000, 10;
+c1	c2	c3	c4	c5
+99010	990	10	abcdefghij	2009-01-01 11:11:11
+98010	1990	10	abcdefghij	2009-01-01 11:11:11
+97010	2990	10	abcdefghij	2009-01-01 11:11:11
+96010	3990	10	abcdefghij	2009-01-01 11:11:11
+95010	4990	10	abcdefghij	2009-01-01 11:11:11
+94010	5990	10	abcdefghij	2009-01-01 11:11:11
+93010	6990	10	abcdefghij	2009-01-01 11:11:11
+92010	7990	10	abcdefghij	2009-01-01 11:11:11
+91010	8990	10	abcdefghij	2009-01-01 11:11:11
+90010	9990	10	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c3,c2 limit 10000, 10;
+c1	c2	c3	c4	c5
+99100	900	100	abcdefghij	2009-01-01 11:11:11
+98100	1900	100	abcdefghij	2009-01-01 11:11:11
+97100	2900	100	abcdefghij	2009-01-01 11:11:11
+96100	3900	100	abcdefghij	2009-01-01 11:11:11
+95100	4900	100	abcdefghij	2009-01-01 11:11:11
+94100	5900	100	abcdefghij	2009-01-01 11:11:11
+93100	6900	100	abcdefghij	2009-01-01 11:11:11
+92100	7900	100	abcdefghij	2009-01-01 11:11:11
+91100	8900	100	abcdefghij	2009-01-01 11:11:11
+90100	9900	100	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c3,c2 limit 100000, 10;
+c1	c2	c3	c4	c5
+select * from s1 order by c3,c1 desc limit 0, 10;
+c1	c2	c3	c4	c5
+100000	0	0	abcdefghij	2009-01-01 11:11:11
+99000	1000	0	abcdefghij	2009-01-01 11:11:11
+98000	2000	0	abcdefghij	2009-01-01 11:11:11
+97000	3000	0	abcdefghij	2009-01-01 11:11:11
+96000	4000	0	abcdefghij	2009-01-01 11:11:11
+95000	5000	0	abcdefghij	2009-01-01 11:11:11
+94000	6000	0	abcdefghij	2009-01-01 11:11:11
+93000	7000	0	abcdefghij	2009-01-01 11:11:11
+92000	8000	0	abcdefghij	2009-01-01 11:11:11
+91000	9000	0	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c3,c1 desc limit 100, 10;
+c1	c2	c3	c4	c5
+99001	999	1	abcdefghij	2009-01-01 11:11:11
+98001	1999	1	abcdefghij	2009-01-01 11:11:11
+97001	2999	1	abcdefghij	2009-01-01 11:11:11
+96001	3999	1	abcdefghij	2009-01-01 11:11:11
+95001	4999	1	abcdefghij	2009-01-01 11:11:11
+94001	5999	1	abcdefghij	2009-01-01 11:11:11
+93001	6999	1	abcdefghij	2009-01-01 11:11:11
+92001	7999	1	abcdefghij	2009-01-01 11:11:11
+91001	8999	1	abcdefghij	2009-01-01 11:11:11
+90001	9999	1	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c3,c1 desc limit 1000, 10;
+c1	c2	c3	c4	c5
+99010	990	10	abcdefghij	2009-01-01 11:11:11
+98010	1990	10	abcdefghij	2009-01-01 11:11:11
+97010	2990	10	abcdefghij	2009-01-01 11:11:11
+96010	3990	10	abcdefghij	2009-01-01 11:11:11
+95010	4990	10	abcdefghij	2009-01-01 11:11:11
+94010	5990	10	abcdefghij	2009-01-01 11:11:11
+93010	6990	10	abcdefghij	2009-01-01 11:11:11
+92010	7990	10	abcdefghij	2009-01-01 11:11:11
+91010	8990	10	abcdefghij	2009-01-01 11:11:11
+90010	9990	10	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c3,c1 desc limit 10000, 10;
+c1	c2	c3	c4	c5
+99100	900	100	abcdefghij	2009-01-01 11:11:11
+98100	1900	100	abcdefghij	2009-01-01 11:11:11
+97100	2900	100	abcdefghij	2009-01-01 11:11:11
+96100	3900	100	abcdefghij	2009-01-01 11:11:11
+95100	4900	100	abcdefghij	2009-01-01 11:11:11
+94100	5900	100	abcdefghij	2009-01-01 11:11:11
+93100	6900	100	abcdefghij	2009-01-01 11:11:11
+92100	7900	100	abcdefghij	2009-01-01 11:11:11
+91100	8900	100	abcdefghij	2009-01-01 11:11:11
+90100	9900	100	abcdefghij	2009-01-01 11:11:11
+select * from s1 order by c3,c1 desc limit 100000, 10;
+c1	c2	c3	c4	c5
+select a.* from s1 a, (select c1, c3 from s1 order by c3,c1 limit 0, 10) b where a.c1 = b.c1;
+c1	c2	c3	c4	c5
+1000	99000	0	abcdefghij	2009-01-01 11:11:11
+2000	98000	0	abcdefghij	2009-01-01 11:11:11
+3000	97000	0	abcdefghij	2009-01-01 11:11:11
+4000	96000	0	abcdefghij	2009-01-01 11:11:11
+5000	95000	0	abcdefghij	2009-01-01 11:11:11
+6000	94000	0	abcdefghij	2009-01-01 11:11:11
+7000	93000	0	abcdefghij	2009-01-01 11:11:11
+8000	92000	0	abcdefghij	2009-01-01 11:11:11
+9000	91000	0	abcdefghij	2009-01-01 11:11:11
+10000	90000	0	abcdefghij	2009-01-01 11:11:11
+select a.* from s1 a, (select c1, c3 from s1 order by c3,c1 limit 100, 10) b where a.c1 = b.c1;
+c1	c2	c3	c4	c5
+1	99999	1	abcdefghij	2009-01-01 11:11:11
+1001	98999	1	abcdefghij	2009-01-01 11:11:11
+2001	97999	1	abcdefghij	2009-01-01 11:11:11
+3001	96999	1	abcdefghij	2009-01-01 11:11:11
+4001	95999	1	abcdefghij	2009-01-01 11:11:11
+5001	94999	1	abcdefghij	2009-01-01 11:11:11
+6001	93999	1	abcdefghij	2009-01-01 11:11:11
+7001	92999	1	abcdefghij	2009-01-01 11:11:11
+8001	91999	1	abcdefghij	2009-01-01 11:11:11
+9001	90999	1	abcdefghij	2009-01-01 11:11:11
+select a.* from s1 a, (select c1, c3 from s1 order by c3,c1 limit 1000, 10) b where a.c1 = b.c1;
+c1	c2	c3	c4	c5
+10	99990	10	abcdefghij	2009-01-01 11:11:11
+1010	98990	10	abcdefghij	2009-01-01 11:11:11
+2010	97990	10	abcdefghij	2009-01-01 11:11:11
+3010	96990	10	abcdefghij	2009-01-01 11:11:11
+4010	95990	10	abcdefghij	2009-01-01 11:11:11
+5010	94990	10	abcdefghij	2009-01-01 11:11:11
+6010	93990	10	abcdefghij	2009-01-01 11:11:11
+7010	92990	10	abcdefghij	2009-01-01 11:11:11
+8010	91990	10	abcdefghij	2009-01-01 11:11:11
+9010	90990	10	abcdefghij	2009-01-01 11:11:11
+select a.* from s1 a, (select c1, c3 from s1 order by c3,c1 limit 10000, 10) b where a.c1 = b.c1;
+c1	c2	c3	c4	c5
+100	99900	100	abcdefghij	2009-01-01 11:11:11
+1100	98900	100	abcdefghij	2009-01-01 11:11:11
+2100	97900	100	abcdefghij	2009-01-01 11:11:11
+3100	96900	100	abcdefghij	2009-01-01 11:11:11
+4100	95900	100	abcdefghij	2009-01-01 11:11:11
+5100	94900	100	abcdefghij	2009-01-01 11:11:11
+6100	93900	100	abcdefghij	2009-01-01 11:11:11
+7100	92900	100	abcdefghij	2009-01-01 11:11:11
+8100	91900	100	abcdefghij	2009-01-01 11:11:11
+9100	90900	100	abcdefghij	2009-01-01 11:11:11
+select a.* from s1 a, (select c1, c3 from s1 order by c3,c1 limit 100000, 10) b where a.c1 = b.c1;
+c1	c2	c3	c4	c5
+select * from s1 order by c1 desc, c2, c3 limit 0, 10;
+c1	c2	c3	c4	c5
+100000	0	0	abcdefghij	2009-01-01 11:11:11
+99999	1	999	abcdefghij	2009-01-01 11:11:11
+99998	2	998	abcdefghij	2009-01-01 11:11:11
+99997	3	997	abcdefghij	2009-01-01 11:11:11
+99996	4	996	abcdefghij	2009-01-01 11:11:11
+99995	5	995	abcdefghij	2009-01-01 11:11:11
+99994	6	994	abcdefghij	2009-01-01 11:11:11
+99993	7	993	abcdefghij	2009-01-01 11:11:11
+99992	8	992	abcdefghij	2009-01-01 11:11:11
+99991	9	991	abcdefghij	2009-01-01 11:11:11
+drop table s1;