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optimisation of independent ALL/ANY with aggregate function (WL#1115) (SCRUM)

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This commit is contained in:
bell@sanja.is.com.ua
2003-08-12 12:38:03 +03:00
parent c06786fa00
commit 6ac8e9b93c
6 changed files with 184 additions and 30 deletions
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89
sql/sql_class.cc
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@@ -986,6 +986,95 @@ bool select_singlerow_subselect::send_data(List<Item> &items)
DBUG_RETURN(0);
}
bool select_max_min_finder_subselect::send_data(List<Item> &items)
{
DBUG_ENTER("select_max_min_finder_subselect::send_data");
Item_singlerow_subselect *it= (Item_singlerow_subselect *)item;
List_iterator_fast<Item> li(items);
Item *val_item= li++;
if (it->assigned())
{
cache->store(val_item);
if ((this->*op)())
it->store(0, cache);
}
else
{
if (!cache)
{
cache= Item_cache::get_cache(val_item->result_type());
switch (val_item->result_type())
{
case REAL_RESULT:
op= &select_max_min_finder_subselect::cmp_real;
break;
case INT_RESULT:
op= &select_max_min_finder_subselect::cmp_int;
break;
case STRING_RESULT:
op= &select_max_min_finder_subselect::cmp_str;
break;
case ROW_RESULT:
// This case should never be choosen
DBUG_ASSERT(0);
op= 0;
}
}
cache->store(val_item);
it->store(0, cache);
}
it->assigned(1);
DBUG_RETURN(0);
}
bool select_max_min_finder_subselect::cmp_real()
{
Item *maxmin= ((Item_singlerow_subselect *)item)->el(0);
double val1= cache->val(), val2= maxmin->val();
if (fmax)
return (cache->null_value && !maxmin->null_value) ||
(!cache->null_value && !maxmin->null_value &&
val1 > val2);
else
return (maxmin->null_value && !cache->null_value) ||
(!cache->null_value && !maxmin->null_value &&
val1 < val2);
}
bool select_max_min_finder_subselect::cmp_int()
{
Item *maxmin= ((Item_singlerow_subselect *)item)->el(0);
longlong val1= cache->val_int(), val2= maxmin->val_int();
if (fmax)
return (cache->null_value && !maxmin->null_value) ||
(!cache->null_value && !maxmin->null_value &&
val1 > val2);
else
return (maxmin->null_value && !cache->null_value) ||
(!cache->null_value && !maxmin->null_value &&
val1 < val2);
}
bool select_max_min_finder_subselect::cmp_str()
{
String *val1, *val2, buf1, buf2;
Item *maxmin= ((Item_singlerow_subselect *)item)->el(0);
/*
as far as both operand is Item_cache buf1 & buf2 will not be used,
but added for safety
*/
val1= cache->val_str(&buf1);
val2= maxmin->val_str(&buf1);
if (fmax)
return (cache->null_value && !maxmin->null_value) ||
(!cache->null_value && !maxmin->null_value &&
sortcmp(val1, val2, cache->collation.collation) > 0) ;
else
return (maxmin->null_value && !cache->null_value) ||
(!cache->null_value && !maxmin->null_value &&
sortcmp(val1, val2, cache->collation.collation) < 0);
}
bool select_exists_subselect::send_data(List<Item> &items)
{
DBUG_ENTER("select_exists_subselect::send_data");