Commit 78d1abba authored by unknown's avatar unknown
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WL#2985 "Partition Pruning": post-review fixes: Better comments 


mysql-test/r/partition_pruning.result:
  WL#2985 "Partition Pruning": more tests
mysql-test/t/partition_pruning.test:
  WL#2985 "Partition Pruning": more tests
sql/handler.h:
  WL#2985 "Partition Pruning": post-review fixes: comments
parent e6bff9a6

mysql-test/r/partition_pruning.result

+15 −0
Original line number Diff line number Diff line
@@ -259,3 +259,18 @@ explain partitions select * from t1 where a is not null; 
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t1	p0,p1	ALL	NULL	NULL	NULL	NULL	2	Using where

drop table t1;

create table t1 (a int not null, b int not null, key(a), key(b))

partition by hash(a) partitions 4;

insert into t1 values (1,1),(2,2),(3,3),(4,4);

explain partitions 

select * from t1 X, t1 Y 

where X.b = Y.b and (X.a=1 or X.a=2) and (Y.a=2 or Y.a=3);

id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	X	p1,p2	ALL	a,b	NULL	NULL	NULL	4	Using where

1	SIMPLE	Y	p2,p3	ref	a,b	b	4	test.X.b	2	Using where

explain partitions

select * from t1 X, t1 Y where X.a = Y.a and (X.a=1 or X.a=2);

id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	X	p1,p2	ALL	a	NULL	NULL	NULL	4	Using where

1	SIMPLE	Y	p1,p2	ref	a	a	4	test.X.a	2	

drop table t1;

mysql-test/t/partition_pruning.test

+14 −1
Original line number Diff line number Diff line
@@ -230,9 +230,22 @@ create table t1 (a int) partition by hash(a) partitions 2; 
insert into t1 values (1),(2);

explain partitions select * from t1 where a is null;



# this selects both

# this uses both partitions

explain partitions select * from t1 where a is not null;

drop table t1;



# Join tests

create table t1 (a int not null, b int not null, key(a), key(b))

  partition by hash(a) partitions 4;

insert into t1 values (1,1),(2,2),(3,3),(4,4);



explain partitions 

select * from t1 X, t1 Y 

where X.b = Y.b and (X.a=1 or X.a=2) and (Y.a=2 or Y.a=3);



explain partitions

select * from t1 X, t1 Y where X.a = Y.a and (X.a=1 or X.a=2);



drop table t1;

# No tests for NULLs in RANGE(monotonic_expr()) - they depend on BUG#15447

# being fixed.

sql/handler.h

+2 −2
Original line number Diff line number Diff line
@@ -567,9 +567,9 @@ class partition_info :public Sql_alloc { 
  */

  get_subpart_id_func get_subpartition_id;

  

  /* NULL-terminated list of fields used in partitioned expression */

  /* NULL-terminated array of fields used in partitioned expression */

  Field **part_field_array;

  /* NULL-terminated list of fields used in subpartitioned expression */

  /* NULL-terminated array of fields used in subpartitioned expression */

  Field **subpart_field_array;



  /*

sql/opt_range.cc

+17 −14
Original line number Diff line number Diff line
@@ -2246,11 +2246,11 @@ typedef struct st_part_prune_param 
 

  /***************************************************************

   Following fields are used to store an 'iterator' that can be 

   used to obtain a set of used artitions.

   used to obtain a set of used partitions.

   **************************************************************/

  /* 

    Start and end+1 partition "numbers". They can have two meanings depending

    depending of the value of part_num_to_part_id:

    of the value of part_num_to_part_id:

    part_num_to_part_id_range - numbers are partition ids

    part_num_to_part_id_list  - numbers are indexes in part_info->list_array

  */
@@ -2536,7 +2536,7 @@ static uint32 part_num_to_part_id_list(PART_PRUNE_PARAM* ppar, uint32 num) 
    List<SEL_IMERGE> represents "imerge1 AND imerge2 AND ...". 

    The set of used partitions is an intersection of used partitions sets

    for imerge_{i}.

    We accumulate this intersection a separate bitmap.

    We accumulate this intersection in a separate bitmap.

 

  RETURN 

    See find_used_partitions()
@@ -2554,7 +2554,7 @@ static int find_used_partitions_imerge_list(PART_PRUNE_PARAM *ppar, 
                                        bitmap_bytes)))

  {

    /* 

      Fallback, process just first SEL_IMERGE. This can leave us with more

      Fallback, process just the first SEL_IMERGE. This can leave us with more

      partitions marked as used then actually needed.

    */

    return find_used_partitions_imerge(ppar, merges.head());
@@ -2623,20 +2623,20 @@ int find_used_partitions_imerge(PART_PRUNE_PARAM *ppar, SEL_IMERGE *imerge) 




/*

  Recursively walk the SEL_ARG tree, find/mark partitions that need to be used

  Collect partitioning ranges for the SEL_ARG tree and mark partitions as used



  SYNOPSIS

    find_used_partitions()

      ppar      Partition pruning context.

      key_tree  Intervals tree to perform pruning for.

      key_tree  SEL_ARG range tree to perform pruning for



  DESCRIPTION

    This function 

      * recursively walks the SEL_ARG* tree collecting partitioning 

        "intervals";

      * finds the partitions one needs to use to get rows in these intervals;

      * marks these partitions as used.

      * recursively walks the SEL_ARG* tree collecting partitioning "intervals"

      * finds the partitions one needs to use to get rows in these intervals

      * marks these partitions as used

  

  NOTES    

    WHAT IS CONSIDERED TO BE "INTERVALS"

    A partition pruning "interval" is equivalent to condition in one of the 

    forms:
@@ -2687,7 +2687,7 @@ int find_used_partitions(PART_PRUNE_PARAM *ppar, SEL_ARG *key_tree) 
    {

      /* 

        Partitioning is done by RANGE|INTERVAL(monotonic_expr(fieldX)), and

        we got "const1 < fieldX < const2" interval.

        we got "const1 CMP fieldX CMP const2" interval

      */

      DBUG_EXECUTE("info", dbug_print_segment_range(key_tree,

                                                    ppar->range_param.
@@ -2761,7 +2761,7 @@ int find_used_partitions(PART_PRUNE_PARAM *ppar, SEL_ARG *key_tree) 
        DBUG_EXECUTE("info", dbug_print_singlepoint_range(ppar->arg_stack,

                                                       ppar->part_fields););

        uint32 part_id;

        /* then find in which partition the {const1, ...,constN} tuple goes */

        /* Find in which partition the {const1, ...,constN} tuple goes */

        if (ppar->get_top_partition_id_func(ppar->part_info, &part_id))

        {

          res= 0; /* No satisfying partitions */
@@ -2843,7 +2843,10 @@ int find_used_partitions(PART_PRUNE_PARAM *ppar, SEL_ARG *key_tree) 


  if (set_full_part_if_bad_ret)

  {

    /* Restore the "used partition iterator" to its default */

    /*

      Restore the "used partitions iterator" to the default setting that

      specifies iteration over all partitions.

    */

    ppar->part_num_to_part_id= part_num_to_part_id_range;

    ppar->start_part_num= 0;

    ppar->end_part_num= ppar->part_info->no_parts;