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This is first cset for WL#1394 "Optimize index merge when all involved index ranges include only values with equal keys"

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The main idea is to exploit the fact that key scans for "key=const" return ordered sequences of rowids.
This commit is contained in:
sergefp@mysql.com
2004-05-13 01:38:40 +04:00
parent b2efad935b
commit a46d7542c9
28 changed files with 3720 additions and 500 deletions
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76
sql/sql_select.cc
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@ -6976,8 +6976,16 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
}
else if (select && select->quick) // Range found by opt_range
{
/* assume results are not ordered when index merge is used */
if (select->quick->get_type() == QUICK_SELECT_I::QS_TYPE_INDEX_MERGE)
int quick_type= select->quick->get_type();
/*
assume results are not ordered when index merge is used
TODO: sergeyp: Results of all index merge selects actually are ordered
by clustered PK values.
*/
if (quick_type == QUICK_SELECT_I::QS_TYPE_INDEX_MERGE ||
quick_type == QUICK_SELECT_I::QS_TYPE_ROR_UNION ||
quick_type == QUICK_SELECT_I::QS_TYPE_ROR_INTERSECT)
DBUG_RETURN(0);
ref_key= select->quick->index;
ref_key_parts= select->quick->used_key_parts;
@ -7038,9 +7046,11 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
*/
if (!select->quick->reverse_sorted())
{
int quick_type= select->quick->get_type();
if (table->file->index_flags(ref_key) & HA_NOT_READ_PREFIX_LAST ||
(select->quick->get_type() ==
QUICK_SELECT_I::QS_TYPE_INDEX_MERGE))
quick_type == QUICK_SELECT_I::QS_TYPE_INDEX_MERGE ||
quick_type == QUICK_SELECT_I::QS_TYPE_ROR_INTERSECT ||
quick_type == QUICK_SELECT_I::QS_TYPE_ROR_UNION)
DBUG_RETURN(0); // Use filesort
// ORDER BY range_key DESC
@ -8961,6 +8971,7 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
select_result *result=join->result;
Item *item_null= new Item_null();
CHARSET_INFO *cs= &my_charset_latin1;
int quick_type= -1;
DBUG_ENTER("select_describe");
DBUG_PRINT("info", ("Select 0x%lx, type %s, message %s",
(ulong)join->select_lex, join->select_lex->type,
@ -9006,8 +9017,10 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
cs));
if (tab->type == JT_ALL && tab->select && tab->select->quick)
{
if (tab->select->quick->get_type() ==
QUICK_SELECT_I::QS_TYPE_INDEX_MERGE)
quick_type= tab->select->quick->get_type();
if ((quick_type == QUICK_SELECT_I::QS_TYPE_INDEX_MERGE) ||
(quick_type == QUICK_SELECT_I::QS_TYPE_ROR_INTERSECT) ||
(quick_type == QUICK_SELECT_I::QS_TYPE_ROR_UNION))
tab->type = JT_INDEX_MERGE;
else
tab->type = JT_RANGE;
@ -9028,6 +9041,7 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
strlen(join_type_str[tab->type]),
cs));
uint j;
/* Build "possible_keys" value and add it to item_list */
if (!tab->keys.is_clear_all())
{
for (j=0 ; j < table->keys ; j++)
@ -9044,6 +9058,8 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
item_list.push_back(new Item_string(tmp1.ptr(),tmp1.length(),cs));
else
item_list.push_back(item_null);
/* Build key,key_len, and ref values and add them to item_list */
if (tab->ref.key_parts)
{
KEY *key_info=table->key_info+ tab->ref.key;
@ -9078,48 +9094,9 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
}
else if (tab->select && tab->select->quick)
{
if (tab->select->quick->get_type() ==
QUICK_SELECT_I::QS_TYPE_INDEX_MERGE)
{
QUICK_INDEX_MERGE_SELECT *quick_imerge=
(QUICK_INDEX_MERGE_SELECT*)tab->select->quick;
QUICK_RANGE_SELECT *quick;
List_iterator_fast<QUICK_RANGE_SELECT> it(quick_imerge->
quick_selects);
while ((quick= it++))
{
KEY *key_info= table->key_info + quick->index;
register uint length;
if (tmp3.length())
tmp3.append(',');
tmp3.append(key_info->name);
if (tmp2.length())
tmp2.append(',');
length= longlong2str(quick->max_used_key_length, keylen_str_buf,
10) -
keylen_str_buf;
tmp2.append(keylen_str_buf, length);
}
}
else
{
KEY *key_info= table->key_info + tab->select->quick->index;
register uint length;
tmp3.append(key_info->name);
length= longlong2str(tab->select->quick->max_used_key_length,
keylen_str_buf, 10) -
keylen_str_buf;
tmp2.append(keylen_str_buf, length);
}
item_list.push_back(new Item_string(tmp3.ptr(),tmp3.length(),cs));
tab->select->quick->fill_keys_and_lengths(&tmp2, &tmp3);
item_list.push_back(new Item_string(tmp2.ptr(),tmp2.length(),cs));
item_list.push_back(new Item_string(tmp3.ptr(),tmp3.length(),cs));
item_list.push_back(item_null);
}
else
@ -9134,7 +9111,10 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
my_bool key_read=table->key_read;
if (tab->type == JT_NEXT && table->used_keys.is_set(tab->index))
key_read=1;
if (quick_type == QUICK_SELECT_I::QS_TYPE_ROR_INTERSECT &&
!((QUICK_ROR_INTERSECT_SELECT*)tab->select->quick)->need_to_fetch_row)
key_read=1;
if (tab->info)
item_list.push_back(new Item_string(tab->info,strlen(tab->info),cs));
else