database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-12-24 11:21:21 +03:00
Code Activity

Added support of null keys in HEAP tables

Browse Source 
Added ORDER BY optimization
This commit is contained in:
monty@tik.mysql.fi
2002-01-12 15:42:54 +02:00
parent 47408baac6
commit 7dd4eb71fe
31 changed files with 547 additions and 148 deletions
Download Patch File Download Diff File Expand all files Collapse all files

139
sql/sql_select.cc
View File

@@ -89,15 +89,18 @@ static int join_read_system(JOIN_TAB *tab);
static int join_read_const(JOIN_TAB *tab);
static int join_read_key(JOIN_TAB *tab);
static int join_read_always_key(JOIN_TAB *tab);
static int join_read_last_key(JOIN_TAB *tab);
static int join_no_more_records(READ_RECORD *info);
static int join_read_next(READ_RECORD *info);
static int join_init_quick_read_record(JOIN_TAB *tab);
static int test_if_quick_select(JOIN_TAB *tab);
static int join_init_read_record(JOIN_TAB *tab);
static int join_init_read_first_with_key(JOIN_TAB *tab);
static int join_init_read_next_with_key(READ_RECORD *info);
static int join_init_read_last_with_key(JOIN_TAB *tab);
static int join_init_read_prev_with_key(READ_RECORD *info);
static int join_read_first(JOIN_TAB *tab);
static int join_read_next(READ_RECORD *info);
static int join_read_next_same(READ_RECORD *info);
static int join_read_last(JOIN_TAB *tab);
static int join_read_prev_same(READ_RECORD *info);
static int join_read_prev(READ_RECORD *info);
static int join_ft_read_first(JOIN_TAB *tab);
static int join_ft_read_next(READ_RECORD *info);
static COND *make_cond_for_table(COND *cond,table_map table,
@@ -2510,7 +2513,7 @@ make_join_readinfo(JOIN *join,uint options)
tab->quick=0;
table->file->index_init(tab->ref.key);
tab->read_first_record= join_read_always_key;
tab->read_record.read_record= join_read_next;
tab->read_record.read_record= join_read_next_same;
if (table->used_keys & ((key_map) 1 << tab->ref.key) &&
!table->no_keyread)
{
@@ -2585,7 +2588,7 @@ make_join_readinfo(JOIN *join,uint options)
{ // Only read index tree
tab->index=find_shortest_key(table, table->used_keys);
tab->table->file->index_init(tab->index);
tab->read_first_record= join_init_read_first_with_key;
tab->read_first_record= join_read_first;
tab->type=JT_NEXT; // Read with index_first / index_next
}
}
@@ -3641,6 +3644,10 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
{
if (field->flags & GROUP_FLAG && !using_unique_constraint)
{
/*
We have to reserve one byte here for NULL bits,
as this is updated by 'end_update()'
*/
*pos++=0; // Null is stored here
recinfo->length=1;
recinfo->type=FIELD_NORMAL;
@@ -3730,11 +3737,11 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
{
/*
To be able to group on NULL, we move the null bit to be
just before the column and extend the key to cover the null bit
just before the column.
The null byte is updated by 'end_update()'
*/
*group_buff= 0; // Init null byte
key_part_info->offset--;
key_part_info->length++;
key_part_info->null_bit=1;
key_part_info->null_offset= key_part_info->offset-1;
group->field->move_field((char*) group_buff+1, (uchar*) group_buff,
1);
}
@@ -4497,6 +4504,35 @@ join_read_always_key(JOIN_TAB *tab)
return 0;
}
/*
This function is used when optimizing away ORDER BY in
SELECT * FROM t1 WHERE a=1 ORDER BY a DESC,b DESC
*/
static int
join_read_last_key(JOIN_TAB *tab)
{
int error;
TABLE *table= tab->table;
if (cp_buffer_from_ref(&tab->ref))
return -1;
if ((error=table->file->index_read_last(table->record[0],
tab->ref.key_buff,
tab->ref.key_length)))
{
if (error != HA_ERR_KEY_NOT_FOUND)
{
sql_print_error("read_const: Got error %d when reading table %s",error,
table->path);
table->file->print_error(error,MYF(0));
return 1;
}
return -1; /* purecov: inspected */
}
return 0;
}
/* ARGSUSED */
static int
@@ -4507,7 +4543,7 @@ join_no_more_records(READ_RECORD *info __attribute__((unused)))
static int
join_read_next(READ_RECORD *info)
join_read_next_same(READ_RECORD *info)
{
int error;
TABLE *table= info->table;
@@ -4530,6 +4566,37 @@ join_read_next(READ_RECORD *info)
return 0;
}
static int
join_read_prev_same(READ_RECORD *info)
{
int error;
TABLE *table= info->table;
JOIN_TAB *tab=table->reginfo.join_tab;
if ((error=table->file->index_prev(table->record[0])))
{
if (error != HA_ERR_END_OF_FILE)
{
sql_print_error("read_next: Got error %d when reading table %s",error,
table->path);
table->file->print_error(error,MYF(0));
error= 1;
}
else
{
table->status= STATUS_GARBAGE;
error= -1;
}
}
else if (key_cmp(table, tab->ref.key_buff, tab->ref.key,
tab->ref.key_length))
{
table->status=STATUS_NOT_FOUND;
error= 1;
}
return error;
}
static int
join_init_quick_read_record(JOIN_TAB *tab)
@@ -4560,7 +4627,7 @@ join_init_read_record(JOIN_TAB *tab)
}
static int
join_init_read_first_with_key(JOIN_TAB *tab)
join_read_first(JOIN_TAB *tab)
{
int error;
TABLE *table=tab->table;
@@ -4571,7 +4638,7 @@ join_init_read_first_with_key(JOIN_TAB *tab)
table->file->extra(HA_EXTRA_KEYREAD);
}
tab->table->status=0;
tab->read_record.read_record=join_init_read_next_with_key;
tab->read_record.read_record=join_read_next;
tab->read_record.table=table;
tab->read_record.file=table->file;
tab->read_record.index=tab->index;
@@ -4591,8 +4658,9 @@ join_init_read_first_with_key(JOIN_TAB *tab)
return 0;
}
static int
join_init_read_next_with_key(READ_RECORD *info)
join_read_next(READ_RECORD *info)
{
int error=info->file->index_next(info->record);
if (error)
@@ -4609,9 +4677,8 @@ join_init_read_next_with_key(READ_RECORD *info)
return 0;
}
static int
join_init_read_last_with_key(JOIN_TAB *tab)
join_read_last(JOIN_TAB *tab)
{
TABLE *table=tab->table;
int error;
@@ -4621,7 +4688,7 @@ join_init_read_last_with_key(JOIN_TAB *tab)
table->file->extra(HA_EXTRA_KEYREAD);
}
tab->table->status=0;
tab->read_record.read_record=join_init_read_prev_with_key;
tab->read_record.read_record=join_read_prev;
tab->read_record.table=table;
tab->read_record.file=table->file;
tab->read_record.index=tab->index;
@@ -4641,8 +4708,9 @@ join_init_read_last_with_key(JOIN_TAB *tab)
return 0;
}
static int
join_init_read_prev_with_key(READ_RECORD *info)
join_read_prev(READ_RECORD *info)
{
int error=info->file->index_prev(info->record);
if (error)
@@ -4659,6 +4727,7 @@ join_init_read_prev_with_key(READ_RECORD *info)
return 0;
}
static int
join_ft_read_first(JOIN_TAB *tab)
{
@@ -4734,7 +4803,8 @@ end_send(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
if (join->select_options & OPTION_FOUND_ROWS)
{
JOIN_TAB *jt=join->join_tab;
if ((join->tables == 1) && !join->tmp_table && !join->sort_and_group && !join->send_group_parts && !join->having && !jt->select_cond )
if ((join->tables == 1) && !join->tmp_table && !join->sort_and_group
&& !join->send_group_parts && !join->having && !jt->select_cond)
{
join->select_options ^= OPTION_FOUND_ROWS;
join->send_records = jt->records;
@@ -5315,6 +5385,9 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
if (ref_key >= 0)
{
/*
We come here when there is a REF key.
*/
int order_direction;
uint used_key_parts;
/* Check if we get the rows in requested sorted order by using the key */
@@ -5322,11 +5395,11 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
(order_direction = test_if_order_by_key(order,table,ref_key,
&used_key_parts)))
{
if (order_direction == -1)
if (order_direction == -1) // If ORDER BY ... DESC
{
if (select && select->quick)
{
// ORDER BY ref_key DESC
// ORDER BY range_key DESC
QUICK_SELECT_DESC *tmp=new QUICK_SELECT_DESC(select->quick,
used_key_parts);
if (!tmp || tmp->error)
@@ -5341,11 +5414,15 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
{
/*
SELECT * FROM t1 WHERE a=1 ORDER BY a DESC,b DESC
TODO:
Add a new traversal function to read last matching row and
traverse backwards.
Use a traversal function that starts by reading the last row
with key part (A) and then traverse the index backwards.
*/
DBUG_RETURN(0);
if (table->file->option_flag() & HA_NOT_READ_PREFIX_LAST)
DBUG_RETURN(1);
tab->read_first_record= join_read_last_key;
tab->read_record.read_record= join_read_prev_same;
/* fall through */
}
}
DBUG_RETURN(1); /* No need to sort */
@@ -5377,8 +5454,8 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
if (!no_changes)
{
tab->index=nr;
tab->read_first_record= (flag > 0 ? join_init_read_first_with_key:
join_init_read_last_with_key);
tab->read_first_record= (flag > 0 ? join_read_first:
join_read_last);
table->file->index_init(nr);
tab->type=JT_NEXT; // Read with index_first(), index_next()
if (table->used_keys & ((key_map) 1 << nr))
@@ -6369,7 +6446,8 @@ get_sort_by_table(ORDER *a,ORDER *b,TABLE_LIST *tables)
static void
calc_group_buffer(JOIN *join,ORDER *group)
{
uint key_length=0,parts=0;
uint key_length=0, parts=0, null_parts=0;
if (group)
join->group= 1;
for (; group ; group=group->next)
@@ -6390,10 +6468,11 @@ calc_group_buffer(JOIN *join,ORDER *group)
key_length+=(*group->item)->max_length;
parts++;
if ((*group->item)->maybe_null)
key_length++;
null_parts++;
}
join->tmp_table_param.group_length=key_length;
join->tmp_table_param.group_length=key_length+null_parts;
join->tmp_table_param.group_parts=parts;
join->tmp_table_param.group_null_parts=null_parts;
}