Commit f37f4b01 authored by unknown's avatar unknown
Browse files

Merge spetrunia@bk-internal.mysql.com:/home/bk/mysql-5.0 

into mysql.com:/home/psergey/mysql-5.0-bug17314
parents 54e0c92d 4b0cce48

myisammrg/myrg_queue.c

+17 −3
Original line number Diff line number Diff line
@@ -18,12 +18,26 @@ 


static int queue_key_cmp(void *keyseg, byte *a, byte *b)

{

  MI_INFO *aa=((MYRG_TABLE *)a)->table;

  MI_INFO *bb=((MYRG_TABLE *)b)->table;

  MYRG_TABLE *ma= (MYRG_TABLE *)a;

  MYRG_TABLE *mb= (MYRG_TABLE *)b;

  MI_INFO *aa= ma->table;

  MI_INFO *bb= mb->table;

  uint not_used[2];

  int ret= ha_key_cmp((HA_KEYSEG *)keyseg, aa->lastkey, bb->lastkey,

		       USE_WHOLE_KEY, SEARCH_FIND, not_used);

  return ret < 0 ? -1 : ret > 0 ? 1 : 0;

  if (ret < 0)

    return -1;

  if (ret > 0)

    return 1;

 

  /*

    If index tuples have the same values, let the record with least rowid

    value be "smaller", so index scans return records ordered by (keytuple,

    rowid). This is used by index_merge access method, grep for ROR in

    sql/opt_range.cc for details.

  */

  return (ma->file_offset < mb->file_offset)? -1 : (ma->file_offset > 

                                                    mb->file_offset) ? 1 : 0;

} /* queue_key_cmp */

mysql-test/r/index_merge.result

+22 −0
Original line number Diff line number Diff line
@@ -402,3 +402,25 @@ explain select * from t1 force index(cola,colb) WHERE cola = 'foo' AND colb = 'b 
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t1	index_merge	cola,colb	cola,colb	3,3	NULL	24	Using intersect(cola,colb); Using where

drop table t1;

create table t0 (a int);

insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);

create table t1 (

a int, b int, 

filler1 char(200), filler2 char(200),

key(a),key(b)

);

insert into t1 select @v:= A.a, @v, 't1', 'filler2' from t0 A, t0 B, t0 C;

create table t2 like t1;

create table t3 (

a int, b int, 

filler1 char(200), filler2 char(200),

key(a),key(b)

) engine=merge union=(t1,t2);

explain select * from t1 where a=1 and b=1;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t1	index_merge	a,b	a,b	5,5	NULL	#	Using intersect(a,b); Using where

explain select * from t3 where a=1 and b=1;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t3	index_merge	a,b	a,b	5,5	NULL	#	Using intersect(a,b); Using where

drop table t3;

drop table t0, t1, t2;

mysql-test/r/merge.result

+1 −1
Original line number Diff line number Diff line
@@ -56,8 +56,8 @@ a b 
4	Testing

5	table

5	table

6	t1

6	t2

6	t1

7	Testing

7	Testing

8	table

mysql-test/t/index_merge.test

+26 −0
Original line number Diff line number Diff line
@@ -357,3 +357,29 @@ explain select * from t1 WHERE cola = 'foo' AND colb = 'bar'; 
explain select * from t1 force index(cola,colb) WHERE cola = 'foo' AND colb = 'bar';

drop table t1;



#

# BUG#17314: Index_merge/intersection not choosen by the optimizer for MERGE tables

#

create table t0 (a int);

insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);

create table t1 (

  a int, b int, 

  filler1 char(200), filler2 char(200),

  key(a),key(b)

);

insert into t1 select @v:= A.a, @v, 't1', 'filler2' from t0 A, t0 B, t0 C;

create table t2 like t1;



create table t3 (

  a int, b int, 

  filler1 char(200), filler2 char(200),

  key(a),key(b)

) engine=merge union=(t1,t2);



--replace_column 9 #

explain select * from t1 where a=1 and b=1;

--replace_column 9 #

explain select * from t3 where a=1 and b=1;



drop table t3;

drop table t0, t1, t2;

sql/ha_myisammrg.cc

+21 −1
Original line number Diff line number Diff line
@@ -288,7 +288,27 @@ void ha_myisammrg::info(uint flag) 
  table->s->db_options_in_use= info.options;

  table->s->is_view= 1;

  mean_rec_length= info.reclength;

  

  /* 

    The handler::block_size is used all over the code in index scan cost

    calculations. It is used to get number of disk seeks required to

    retrieve a number of index tuples.

    If the merge table has N underlying tables, then (assuming underlying

    tables have equal size, the only "simple" approach we can use)

    retrieving X index records from a merge table will require N times more

    disk seeks compared to doing the same on a MyISAM table with equal

    number of records.

    In the edge case (file_tables > myisam_block_size) we'll get

    block_size==0, and index calculation code will act as if we need one

    disk seek to retrieve one index tuple.



    TODO: In 5.2 index scan cost calculation will be factored out into a

    virtual function in class handler and we'll be able to remove this hack.

  */

  block_size= 0;

  if (file->tables)

    block_size= myisam_block_size / file->tables;

  

  update_time=0;

#if SIZEOF_OFF_T > 4

  ref_length=6;					// Should be big enough