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MDEV-26996 Support descending indexes in the range optimizer

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Make the Range Optimizer support descending index key parts.

We follow the approach taken in MySQL-8.

See HowRangeOptimizerHandlesDescKeyparts for the description.
This commit is contained in:
Sergei Petrunia
2021-12-14 01:47:01 +03:00
committed by Sergei Golubchik
parent a4cac0e07a
commit 791146b9d2
7 changed files with 582 additions and 102 deletions
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162
sql/opt_range.cc
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@@ -1879,6 +1879,7 @@ SEL_ARG::SEL_ARG(SEL_ARG &arg) :Sql_alloc()
max_flag=arg.max_flag;
maybe_flag=arg.maybe_flag;
maybe_null=arg.maybe_null;
is_ascending= arg.is_ascending;
part=arg.part;
field=arg.field;
min_value=arg.min_value;
@@ -1904,9 +1905,10 @@ inline void SEL_ARG::make_root()
use_count=0; elements=1;
}
SEL_ARG::SEL_ARG(Field *f,const uchar *min_value_arg,
SEL_ARG::SEL_ARG(Field *f, bool is_asc, const uchar *min_value_arg,
const uchar *max_value_arg)
:min_flag(0), max_flag(0), maybe_flag(0), maybe_null(f->real_maybe_null()),
is_ascending(is_asc),
elements(1), use_count(1), field(f), min_value((uchar*) min_value_arg),
max_value((uchar*) max_value_arg), next(0),prev(0),
next_key_part(0), color(BLACK), type(KEY_RANGE), weight(1)
@@ -1915,11 +1917,12 @@ SEL_ARG::SEL_ARG(Field *f,const uchar *min_value_arg,
max_part_no= 1;
}
SEL_ARG::SEL_ARG(Field *field_,uint8 part_,
SEL_ARG::SEL_ARG(Field *field_,uint8 part_, bool is_asc_,
uchar *min_value_, uchar *max_value_,
uint8 min_flag_,uint8 max_flag_,uint8 maybe_flag_)
:min_flag(min_flag_),max_flag(max_flag_),maybe_flag(maybe_flag_),
part(part_),maybe_null(field_->real_maybe_null()), elements(1),use_count(1),
part(part_),maybe_null(field_->real_maybe_null()), is_ascending(is_asc_),
elements(1),use_count(1),
field(field_), min_value(min_value_), max_value(max_value_),
next(0),prev(0),next_key_part(0),color(BLACK),type(KEY_RANGE), weight(1)
{
@@ -1938,8 +1941,8 @@ SEL_ARG::SEL_ARG(Field *field_,uint8 part_,
class SEL_ARG_LE: public SEL_ARG
{
public:
SEL_ARG_LE(const uchar *key, Field *field)
:SEL_ARG(field, key, key)
SEL_ARG_LE(const uchar *key, Field *field, bool is_asc)
:SEL_ARG(field, is_asc, key, key)
{
if (!field->real_maybe_null())
min_flag= NO_MIN_RANGE; // From start
@@ -1959,16 +1962,17 @@ public:
Use this constructor if value->save_in_field() went precisely,
without any data rounding or truncation.
*/
SEL_ARG_LT(const uchar *key, Field *field)
:SEL_ARG_LE(key, field)
SEL_ARG_LT(const uchar *key, Field *field, bool is_asc)
:SEL_ARG_LE(key, field, is_asc)
{ max_flag= NEAR_MAX; }
/*
Use this constructor if value->save_in_field() returned success,
but we don't know if rounding or truncation happened
(as some Field::store() do not report minor data changes).
*/
SEL_ARG_LT(THD *thd, const uchar *key, Field *field, Item *value)
:SEL_ARG_LE(key, field)
SEL_ARG_LT(THD *thd, const uchar *key, Field *field, bool is_asc,
Item *value)
:SEL_ARG_LE(key, field, is_asc)
{
if (stored_field_cmp_to_item(thd, field, value) == 0)
max_flag= NEAR_MAX;
@@ -1984,7 +1988,7 @@ public:
without any data rounding or truncation.
*/
SEL_ARG_GT(const uchar *key, const KEY_PART *key_part, Field *field)
:SEL_ARG(field, key, key)
:SEL_ARG(field, !(key_part->flag & HA_REVERSE_SORT), key, key)
{
// Don't use open ranges for partial key_segments
if (!(key_part->flag & HA_PART_KEY_SEG))
@@ -1998,7 +2002,7 @@ public:
*/
SEL_ARG_GT(THD *thd, const uchar *key,
const KEY_PART *key_part, Field *field, Item *value)
:SEL_ARG(field, key, key)
:SEL_ARG(field, !(key_part->flag & HA_REVERSE_SORT), key, key)
{
// Don't use open ranges for partial key_segments
if ((!(key_part->flag & HA_PART_KEY_SEG)) &&
@@ -2016,8 +2020,8 @@ public:
Use this constructor if value->save_in_field() went precisely,
without any data rounding or truncation.
*/
SEL_ARG_GE(const uchar *key, Field *field)
:SEL_ARG(field, key, key)
SEL_ARG_GE(const uchar *key, Field *field, bool is_asc)
:SEL_ARG(field, is_asc, key, key)
{
max_flag= NO_MAX_RANGE;
}
@@ -2028,7 +2032,7 @@ public:
*/
SEL_ARG_GE(THD *thd, const uchar *key,
const KEY_PART *key_part, Field *field, Item *value)
:SEL_ARG(field, key, key)
:SEL_ARG(field, !(key_part->flag & HA_REVERSE_SORT), key, key)
{
// Don't use open ranges for partial key_segments
if ((!(key_part->flag & HA_PART_KEY_SEG)) &&
@@ -2059,7 +2063,8 @@ SEL_ARG *SEL_ARG::clone(RANGE_OPT_PARAM *param, SEL_ARG *new_parent,
}
else
{
if (!(tmp= new (param->mem_root) SEL_ARG(field,part, min_value,max_value,
if (!(tmp= new (param->mem_root) SEL_ARG(field, part, is_ascending,
min_value, max_value,
min_flag, max_flag, maybe_flag)))
return 0; // OOM
tmp->parent=new_parent;
@@ -2830,6 +2835,7 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
}
trace_keypart.end();
trace_idx_details.add("usable", !unusable_has_desc_keyparts);
unusable_has_desc_keyparts= false;
if (unusable_has_desc_keyparts) // TODO MDEV-13756
{
key_parts= param.key[param.keys];
@@ -4423,12 +4429,14 @@ int find_used_partitions(PART_PRUNE_PARAM *ppar, SEL_ARG *key_tree)
key_tree->next_key_part->store_min_key(ppar->key,
&tmp_min_key,
&tmp_min_flag,
ppar->last_part_partno);
ppar->last_part_partno,
true);
if (!tmp_max_flag)
key_tree->next_key_part->store_max_key(ppar->key,
&tmp_max_key,
&tmp_max_flag,
ppar->last_part_partno);
ppar->last_part_partno,
false);
flag= tmp_min_flag | tmp_max_flag;
}
else
@@ -8674,7 +8682,8 @@ Item_func_null_predicate::get_mm_leaf(RANGE_OPT_PARAM *param,
if (!field->real_maybe_null())
DBUG_RETURN(type == ISNULL_FUNC ? &null_element : NULL);
SEL_ARG *tree;
if (!(tree= new (alloc) SEL_ARG(field, is_null_string, is_null_string)))
bool is_asc= !(key_part->flag & HA_REVERSE_SORT);
if (!(tree= new (alloc) SEL_ARG(field, is_asc, is_null_string, is_null_string)))
DBUG_RETURN(0);
if (type == Item_func::ISNOTNULL_FUNC)
{
@@ -8774,7 +8783,8 @@ Item_func_like::get_mm_leaf(RANGE_OPT_PARAM *param,
int2store(min_str + maybe_null, min_length);
int2store(max_str + maybe_null, max_length);
}
SEL_ARG *tree= new (param->mem_root) SEL_ARG(field, min_str, max_str);
bool is_asc= !(key_part->flag & HA_REVERSE_SORT);
SEL_ARG *tree= new (param->mem_root) SEL_ARG(field, is_asc, min_str, max_str);
DBUG_RETURN(tree);
}
@@ -9022,18 +9032,19 @@ SEL_ARG *Field::stored_field_make_mm_leaf(RANGE_OPT_PARAM *param,
if (!(str= make_key_image(param->mem_root, key_part)))
DBUG_RETURN(0);
bool is_asc= !(key_part->flag & HA_REVERSE_SORT);
switch (op) {
case SCALAR_CMP_LE:
DBUG_RETURN(new (mem_root) SEL_ARG_LE(str, this));
DBUG_RETURN(new (mem_root) SEL_ARG_LE(str, this, is_asc));
case SCALAR_CMP_LT:
DBUG_RETURN(new (mem_root) SEL_ARG_LT(thd, str, this, value));
DBUG_RETURN(new (mem_root) SEL_ARG_LT(thd, str, this, is_asc, value));
case SCALAR_CMP_GT:
DBUG_RETURN(new (mem_root) SEL_ARG_GT(thd, str, key_part, this, value));
case SCALAR_CMP_GE:
DBUG_RETURN(new (mem_root) SEL_ARG_GE(thd, str, key_part, this, value));
case SCALAR_CMP_EQ:
case SCALAR_CMP_EQUAL:
DBUG_RETURN(new (mem_root) SEL_ARG(this, str, str));
DBUG_RETURN(new (mem_root) SEL_ARG(this, is_asc, str, str));
break;
}
DBUG_ASSERT(0);
@@ -9051,18 +9062,19 @@ SEL_ARG *Field::stored_field_make_mm_leaf_exact(RANGE_OPT_PARAM *param,
if (!(str= make_key_image(param->mem_root, key_part)))
DBUG_RETURN(0);
bool is_asc= !(key_part->flag & HA_REVERSE_SORT);
switch (op) {
case SCALAR_CMP_LE:
DBUG_RETURN(new (param->mem_root) SEL_ARG_LE(str, this));
DBUG_RETURN(new (param->mem_root) SEL_ARG_LE(str, this, is_asc));
case SCALAR_CMP_LT:
DBUG_RETURN(new (param->mem_root) SEL_ARG_LT(str, this));
DBUG_RETURN(new (param->mem_root) SEL_ARG_LT(str, this, is_asc));
case SCALAR_CMP_GT:
DBUG_RETURN(new (param->mem_root) SEL_ARG_GT(str, key_part, this));
case SCALAR_CMP_GE:
DBUG_RETURN(new (param->mem_root) SEL_ARG_GE(str, this));
DBUG_RETURN(new (param->mem_root) SEL_ARG_GE(str, this, is_asc));
case SCALAR_CMP_EQ:
case SCALAR_CMP_EQUAL:
DBUG_RETURN(new (param->mem_root) SEL_ARG(this, str, str));
DBUG_RETURN(new (param->mem_root) SEL_ARG(this, is_asc, str, str));
break;
}
DBUG_ASSERT(0);
@@ -11780,6 +11792,46 @@ get_quick_select(PARAM *param,uint idx,SEL_ARG *key_tree, uint mrr_flags,
}
void SEL_ARG::store_next_min_max_keys(KEY_PART *key,
uchar **cur_min_key, uint *cur_min_flag,
uchar **cur_max_key, uint *cur_max_flag,
int *min_part, int *max_part)
{
DBUG_ASSERT(next_key_part);
bool asc = next_key_part->is_ascending;
if (!get_min_flag())
{
if (asc)
{
*min_part += next_key_part->store_min_key(key, cur_min_key,
cur_min_flag, MAX_KEY, true);
}
else
{
uint tmp_flag = invert_min_flag(*cur_min_flag);
*min_part += next_key_part->store_max_key(key, cur_min_key, &tmp_flag,
MAX_KEY, true);
*cur_min_flag = invert_max_flag(tmp_flag);
}
}
if (!get_max_flag())
{
if (asc)
{
*max_part += next_key_part->store_max_key(key, cur_max_key,
cur_max_flag, MAX_KEY, false);
}
else
{
uint tmp_flag = invert_max_flag(*cur_max_flag);
*max_part += next_key_part->store_min_key(key, cur_max_key, &tmp_flag,
MAX_KEY, false);
*cur_max_flag = invert_min_flag(tmp_flag);
}
}
}
/*
** Fix this to get all possible sub_ranges
*/
@@ -11793,17 +11845,19 @@ get_quick_keys(PARAM *param,QUICK_RANGE_SELECT *quick,KEY_PART *key,
int min_part= key_tree->part-1, // # of keypart values in min_key buffer
max_part= key_tree->part-1; // # of keypart values in max_key buffer
if (key_tree->left != &null_element)
SEL_ARG *next_tree = key_tree->is_ascending ? key_tree->left : key_tree->right;
if (next_tree != &null_element)
{
if (get_quick_keys(param,quick,key,key_tree->left,
if (get_quick_keys(param,quick,key,next_tree,
min_key,min_key_flag, max_key, max_key_flag))
return 1;
}
uchar *tmp_min_key=min_key,*tmp_max_key=max_key;
min_part+= key_tree->store_min(key[key_tree->part].store_length,
&tmp_min_key,min_key_flag);
max_part+= key_tree->store_max(key[key_tree->part].store_length,
&tmp_max_key,max_key_flag);
key_tree->store_min_max(key[key_tree->part].store_length,
&tmp_min_key, min_key_flag,
&tmp_max_key, max_key_flag,
&min_part, &max_part);
if (key_tree->next_key_part &&
key_tree->next_key_part->type == SEL_ARG::KEY_RANGE &&
@@ -11813,31 +11867,40 @@ get_quick_keys(PARAM *param,QUICK_RANGE_SELECT *quick,KEY_PART *key,
memcmp(min_key, max_key, (uint)(tmp_max_key - max_key))==0 &&
key_tree->min_flag==0 && key_tree->max_flag==0)
{
// psergey-note: simplified the parameters below as follows:
// min_key_flag | key_tree->min_flag -> min_key_flag
// max_key_flag | key_tree->max_flag -> max_key_flag
if (get_quick_keys(param,quick,key,key_tree->next_key_part,
tmp_min_key, min_key_flag | key_tree->min_flag,
tmp_max_key, max_key_flag | key_tree->max_flag))
tmp_min_key, min_key_flag,
tmp_max_key, max_key_flag))
return 1;
goto end; // Ugly, but efficient
}
{
uint tmp_min_flag=key_tree->min_flag,tmp_max_flag=key_tree->max_flag;
if (!tmp_min_flag)
min_part+= key_tree->next_key_part->store_min_key(key,
&tmp_min_key,
&tmp_min_flag,
MAX_KEY);
if (!tmp_max_flag)
max_part+= key_tree->next_key_part->store_max_key(key,
&tmp_max_key,
&tmp_max_flag,
MAX_KEY);
uint tmp_min_flag= key_tree->get_min_flag();
uint tmp_max_flag= key_tree->get_max_flag();
key_tree->store_next_min_max_keys(key,
&tmp_min_key, &tmp_min_flag,
&tmp_max_key, &tmp_max_flag,
&min_part, &max_part);
flag=tmp_min_flag | tmp_max_flag;
}
}
else
{
flag = (key_tree->min_flag & GEOM_FLAG) ?
key_tree->min_flag : key_tree->min_flag | key_tree->max_flag;
if (key_tree->is_ascending)
{
flag= (key_tree->min_flag & GEOM_FLAG) ? key_tree->min_flag:
(key_tree->min_flag |
key_tree->max_flag);
}
else
{
// Invert flags for DESC keypart
flag= invert_min_flag(key_tree->min_flag) |
invert_max_flag(key_tree->max_flag);
}
}
/*
@@ -11898,8 +11961,9 @@ get_quick_keys(PARAM *param,QUICK_RANGE_SELECT *quick,KEY_PART *key,
return 1;
end:
if (key_tree->right != &null_element)
return get_quick_keys(param,quick,key,key_tree->right,
next_tree = key_tree->is_ascending ? key_tree->right : key_tree->left;
if (next_tree != &null_element)
return get_quick_keys(param,quick,key,next_tree,
min_key,min_key_flag,
max_key,max_key_flag);
return 0;