MySQL数据库

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Visual C++

sql_select.cpp：源码内容

{
return new store_key_const_item(thd,
key_part->field,
key_buff + maybe_null,
maybe_null ? key_buff : 0,
key_part->length,
keyuse->val);
}
else if (keyuse->val->type() == Item::FIELD_ITEM)
return new store_key_field(thd,
key_part->field,
key_buff + maybe_null,
maybe_null ? key_buff : 0,
key_part->length,
((Item_field*) keyuse->val)->field,
keyuse->val->full_name());
return new store_key_item(thd,
key_part->field,
key_buff + maybe_null,
maybe_null ? key_buff : 0,
key_part->length,
keyuse->val);
}
/*
This function is only called for const items on fields which are keys
returns 1 if there was some conversion made when the field was stored.
*/
bool
store_val_in_field(Field *field,Item *item)
{
bool error;
THD *thd=current_thd;
ha_rows cuted_fields=thd->cuted_fields;
/*
we should restore old value of count_cuted_fields because
store_val_in_field can be called from mysql_insert
with select_insert, which make count_cuted_fields= 1
*/
enum_check_fields old_count_cuted_fields= thd->count_cuted_fields;
thd->count_cuted_fields= CHECK_FIELD_WARN;
error= item->save_in_field(field, 1);
thd->count_cuted_fields= old_count_cuted_fields;
return error || cuted_fields != thd->cuted_fields;
}
static bool
make_simple_join(JOIN *join,TABLE *tmp_table)
{
TABLE **tableptr;
JOIN_TAB *join_tab;
if (!(tableptr=(TABLE**) join->thd->alloc(sizeof(TABLE*))) ||
!(join_tab=(JOIN_TAB*) join->thd->alloc(sizeof(JOIN_TAB))))
return TRUE;
join->join_tab=join_tab;
join->table=tableptr; tableptr[0]=tmp_table;
join->tables=1;
join->const_tables=0;
join->const_table_map=0;
join->tmp_table_param.field_count= join->tmp_table_param.sum_func_count=
join->tmp_table_param.func_count=0;
join->tmp_table_param.copy_field=join->tmp_table_param.copy_field_end=0;
join->first_record=join->sort_and_group=0;
join->send_records=(ha_rows) 0;
join->group=0;
join->row_limit=join->unit->select_limit_cnt;
join->do_send_rows = (join->row_limit) ? 1 : 0;
join_tab->cache.buff=0; /* No caching */
join_tab->table=tmp_table;
join_tab->select=0;
join_tab->select_cond=0;
join_tab->quick=0;
join_tab->type= JT_ALL; /* Map through all records */
join_tab->keys.init();
join_tab->keys.set_all(); /* test everything in quick */
join_tab->info=0;
join_tab->on_expr=0;
join_tab->ref.key = -1;
join_tab->not_used_in_distinct=0;
join_tab->read_first_record= join_init_read_record;
join_tab->join=join;
bzero((char*) &join_tab->read_record,sizeof(join_tab->read_record));
tmp_table->status=0;
tmp_table->null_row=0;
return FALSE;
}
inline void add_cond_and_fix(Item **e1, Item *e2)
{
if (*e1)
{
Item *res;
if ((res= new Item_cond_and(*e1, e2)))
{
*e1= res;
res->quick_fix_field();
}
}
else
*e1= e2;
}
/*
Add to join_tab->select_cond[i] "table.field IS NOT NULL" conditions we've
inferred from ref/eq_ref access performed.
SYNOPSIS
add_not_null_conds()
join Join to process
NOTES
This function is a part of "Early NULL-values filtering for ref access"
optimization.
Example of this optimization:
For query SELECT * FROM t1,t2 WHERE t2.key=t1.field
and plan " any-access(t1), ref(t2.key=t1.field) "
add "t1.field IS NOT NULL" to t1's table condition.
Description of the optimization:
We look through equalities choosen to perform ref/eq_ref access,
pick equalities that have form "tbl.part_of_key = othertbl.field"
(where othertbl is a non-const table and othertbl.field may be NULL)
and add them to conditions on correspoding tables (othertbl in this
example).
Exception from that is the case when referred_tab->join != join.
I.e. don't add NOT NULL constraints from any embedded subquery.
Consider this query:
SELECT A.f2 FROM t1 LEFT JOIN t2 A ON A.f2 = f1
WHERE A.f3=(SELECT MIN(f3) FROM t2 C WHERE A.f4 = C.f4) OR A.f3 IS NULL;
Here condition A.f3 IS NOT NULL is going to be added to the WHERE
condition of the embedding query.
Another example:
SELECT * FROM t10, t11 WHERE (t10.a < 10 OR t10.a IS NULL)
AND t11.b <=> t10.b AND (t11.a = (SELECT MAX(a) FROM t12
WHERE t12.b = t10.a ));
Here condition t10.a IS NOT NULL is going to be added.
In both cases addition of NOT NULL condition will erroneously reject
some rows of the result set.
referred_tab->join != join constraint would disallow such additions.
This optimization doesn't affect the choices that ref, range, or join
optimizer make. This was intentional because this was added after 4.1
was GA.
Implementation overview
1. update_ref_and_keys() accumulates info about null-rejecting
predicates in in KEY_FIELD::null_rejecting
1.1 add_key_part saves these to KEYUSE.
2. create_ref_for_key copies them to TABLE_REF.
3. add_not_null_conds adds "x IS NOT NULL" to join_tab->select_cond of
appropiate JOIN_TAB members.
*/
static void add_not_null_conds(JOIN *join)
{
DBUG_ENTER("add_not_null_conds");
for (uint i=join->const_tables ; i < join->tables ; i++)
{
JOIN_TAB *tab=join->join_tab+i;
if ((tab->type == JT_REF || tab->type == JT_REF_OR_NULL) &&
!tab->table->maybe_null)
{
for (uint keypart= 0; keypart < tab->ref.key_parts; keypart++)
{
if (tab->ref.null_rejecting & (1 << keypart))
{
Item *item= tab->ref.items[keypart];
Item *notnull;
DBUG_ASSERT(item->type() == Item::FIELD_ITEM);
Item_field *not_null_item= (Item_field*)item;
JOIN_TAB *referred_tab= not_null_item->field->table->reginfo.join_tab;
/*
For UPDATE queries such as:
UPDATE t1 SET t1.f2=(SELECT MAX(t2.f4) FROM t2 WHERE t2.f3=t1.f1);
not_null_item is the t1.f1, but it's referred_tab is 0.
*/
if (!referred_tab || referred_tab->join != join)
continue;
if (!(notnull= new Item_func_isnotnull(not_null_item)))
DBUG_VOID_RETURN;
/*
We need to do full fix_fields() call here in order to have correct
notnull->const_item(). This is needed e.g. by test_quick_select
when it is called from make_join_select after this function is
called.
*/
if (notnull->fix_fields(join->thd, join->tables_list, &notnull))
DBUG_VOID_RETURN;
DBUG_EXECUTE("where",print_where(notnull,
referred_tab->table->table_name););
add_cond_and_fix(&referred_tab->select_cond, notnull);
}
}
}
}
DBUG_VOID_RETURN;
}
static bool
make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
{
DBUG_ENTER("make_join_select");
if (select)
{
add_not_null_conds(join);
table_map used_tables;
if (join->tables > 1)
cond->update_used_tables(); // Tablenr may have changed
if (join->const_tables == join->tables &&
join->thd->lex->current_select->master_unit() ==
&join->thd->lex->unit) // not upper level SELECT
join->const_table_map|=RAND_TABLE_BIT;
{ // Check const tables
COND *const_cond=
make_cond_for_table(cond,join->const_table_map,(table_map) 0);
DBUG_EXECUTE("where",print_where(const_cond,"constants"););
if (const_cond && !const_cond->val_int())
{
DBUG_PRINT("info",("Found impossible WHERE condition"));
DBUG_RETURN(1); // Impossible const condition
}
}
used_tables=((select->const_tables=join->const_table_map) |
OUTER_REF_TABLE_BIT | RAND_TABLE_BIT);
for (uint i=join->const_tables ; i < join->tables ; i++)
{
JOIN_TAB *tab=join->join_tab+i;
table_map current_map= tab->table->map;
/*
Following force including random expression in last table condition.
It solve problem with select like SELECT * FROM t1 WHERE rand() > 0.5
*/
if (i == join->tables-1)
current_map|= OUTER_REF_TABLE_BIT | RAND_TABLE_BIT;
bool use_quick_range=0;
used_tables|=current_map;
if (tab->type == JT_REF && tab->quick &&
(uint) tab->ref.key == tab->quick->index &&
tab->ref.key_length < tab->quick->max_used_key_length)
{
/* Range uses longer key; Use this instead of ref on key */
tab->type=JT_ALL;
use_quick_range=1;
tab->use_quick=1;
tab->ref.key= -1;
tab->ref.key_parts=0; // Don't use ref key.
join->best_positions[i].records_read= rows2double(tab->quick->records);
}
COND *tmp=make_cond_for_table(cond,used_tables,current_map);
if (!tmp && tab->quick)
{ // Outer join
/*
Hack to handle the case where we only refer to a table
in the ON part of an OUTER JOIN.
*/
tmp=new Item_int((longlong) 1,1); // Always true
}
if (tmp)
{
SQL_SELECT *sel=tab->select=(SQL_SELECT*)
join->thd->memdup((gptr) select, sizeof(SQL_SELECT));
if (!sel)
DBUG_RETURN(1); // End of memory
add_cond_and_fix(&tab->select_cond, tmp);
sel->cond= tab->select_cond;
sel->head=tab->table;
DBUG_EXECUTE("where",print_where(tmp,tab->table->table_name););
if (tab->quick)
{
/* Use quick key read if it's a constant and it's not used
with key reading */
if (tab->needed_reg.is_clear_all() && tab->type != JT_EQ_REF
&& tab->type != JT_FT && (tab->type != JT_REF ||
(uint) tab->ref.key == tab->quick->index))
{
sel->quick=tab->quick; // Use value from get_quick_...
sel->quick_keys.clear_all();
sel->needed_reg.clear_all();
}
else
{
delete tab->quick;
}
tab->quick=0;
}
uint ref_key=(uint) sel->head->reginfo.join_tab->ref.key+1;
if (i == join->const_tables && ref_key)
{
if (!tab->const_keys.is_clear_all() &&
tab->table->reginfo.impossible_range)
DBUG_RETURN(1);
}
else if (tab->type == JT_ALL && ! use_quick_range)
{
if (!tab->const_keys.is_clear_all() &&
tab->table->reginfo.impossible_range)
DBUG_RETURN(1); // Impossible range
/*
We plan to scan all rows.
Check again if we should use an index.
We could have used an column from a previous table in
the index if we are using limit and this is the first table
*/
if ((!tab->keys.is_subset(tab->const_keys) && i > 0) ||
(!tab->const_keys.is_clear_all() && i == join->const_tables &&
join->unit->select_limit_cnt <
join->best_positions[i].records_read &&
!(join->select_options & OPTION_FOUND_ROWS)))
{
/* Join with outer join condition */
COND *orig_cond=sel->cond;
sel->cond= and_conds(sel->cond, tab->on_expr);
/*
We can't call sel->cond->fix_fields,
as it will break tab->on_expr if it's AND condition
(fix_fields currently removes extra AND/OR levels).
Yet attributes of the just built condition are not needed.
Thus we call sel->cond->quick_fix_field for safety.
*/
if (sel->cond && !sel->cond->fixed)
sel->cond->quick_fix_field();
if (sel->test_quick_select(join->thd, tab->keys,
used_tables & ~ current_map,
(join->select_options &
OPTION_FOUND_ROWS ?
HA_POS_ERROR :
join->unit->select_limit_cnt), 0) < 0)
{
/*
Before reporting "Impossible WHERE" for the whole query
we have to check isn't it only "impossible ON" instead
*/
sel->cond=orig_cond;
if (!tab->on_expr ||
sel->test_quick_select(join->thd, tab->keys,
used_tables & ~ current_map,
(join->select_options &
OPTION_FOUND_ROWS ?
HA_POS_ERROR :
join->unit->select_limit_cnt),0) < 0)
DBUG_RETURN(1); // Impossible WHERE
}
else
sel->cond=orig_cond;
/* Fix for EXPLAIN */
if (sel->quick)
join->best_positions[i].records_read= sel->quick->records;
}
else
{
sel->needed_reg=tab->needed_reg;
sel->quick_keys.clear_all();
}
if (!sel->quick_keys.is_subset(tab->checked_keys) ||
!sel->needed_reg.is_subset(tab->checked_keys))
{
tab->keys=sel->quick_keys;
tab->keys.merge(sel->needed_reg);
tab->use_quick= (!sel->needed_reg.is_clear_all() &&
(select->quick_keys.is_clear_all() ||
(select->quick &&
(select->quick->records >= 100L)))) ?
2 : 1;
sel->read_tables= used_tables & ~current_map;
}
if (i != join->const_tables && tab->use_quick != 2)
{ /* Read with cache */
if ((tmp=make_cond_for_table(cond,
join->const_table_map |
current_map,
current_map)))
{
DBUG_EXECUTE("where",print_where(tmp,"cache"););
tab->cache.select=(SQL_SELECT*)
join->thd->memdup((gptr) sel, sizeof(SQL_SELECT));
tab->cache.select->cond=tmp;
tab->cache.select->read_tables=join->const_table_map;
}
}
}
}
}
}
DBUG_RETURN(0);
}
static void
make_join_readinfo(JOIN *join, uint options)
{
uint i;
bool statistics= test(!(join->select_options & SELECT_DESCRIBE));
DBUG_ENTER("make_join_readinfo");
for (i=join->const_tables ; i < join->tables ; i++)
{
JOIN_TAB *tab=join->join_tab+i;
TABLE *table=tab->table;
tab->read_record.table= table;
tab->read_record.file=table->file;
tab->next_select=sub_select; /* normal select */
switch (tab->type) {
case JT_SYSTEM: // Only happens with left join
table->status=STATUS_NO_RECORD;
tab->read_first_record= join_read_system;
tab->read_record.read_record= join_no_more_records;
break;
case JT_CONST: // Only happens with left join
table->status=STATUS_NO_RECORD;
tab->read_first_record= join_read_const;
tab->read_record.read_record= join_no_more_records;
if (table->used_keys.is_set(tab->ref.key) &&
!table->no_keyread)
{
table->key_read=1;
table->file->extra(HA_EXTRA_KEYREAD);
}
break;
case JT_EQ_REF:
table->status=STATUS_NO_RECORD;
if (tab->select)
{
delete tab->select->quick;
tab->select->quick=0;
}
delete tab->quick;
tab->quick=0;
tab->read_first_record= join_read_key;
tab->read_record.read_record= join_no_more_records;
if (table->used_keys.is_set(tab->ref.key) &&
!table->no_keyread)
{
table->key_read=1;
table->file->extra(HA_EXTRA_KEYREAD);
}
break;
case JT_REF_OR_NULL:
case JT_REF:
table->status=STATUS_NO_RECORD;
if (tab->select)
{
delete tab->select->quick;
tab->select->quick=0;
}
delete tab->quick;
tab->quick=0;
if (table->used_keys.is_set(tab->ref.key) &&
!table->no_keyread)
{
table->key_read=1;
table->file->extra(HA_EXTRA_KEYREAD);
}
if (tab->type == JT_REF)
{
tab->read_first_record= join_read_always_key;
tab->read_record.read_record= join_read_next_same;
}
else
{
tab->read_first_record= join_read_always_key_or_null;
tab->read_record.read_record= join_read_next_same_or_null;
}
break;
case JT_FT:
table->status=STATUS_NO_RECORD;
tab->read_first_record= join_ft_read_first;
tab->read_record.read_record= join_ft_read_next;
break;
case JT_ALL:
/*
If previous table use cache
*/
table->status=STATUS_NO_RECORD;
if (i != join->const_tables && !(options & SELECT_NO_JOIN_CACHE) &&
tab->use_quick != 2 && !tab->on_expr)
{
if ((options & SELECT_DESCRIBE) ||
!join_init_cache(join->thd,join->join_tab+join->const_tables,
i-join->const_tables))
{
tab[-1].next_select=sub_select_cache; /* Patch previous */
}
}
/* These init changes read_record */
if (tab->use_quick == 2)
{
join->thd->server_status|=SERVER_QUERY_NO_GOOD_INDEX_USED;
tab->read_first_record= join_init_quick_read_record;
if (statistics)
statistic_increment(select_range_check_count, &LOCK_status);
}
else
{
tab->read_first_record= join_init_read_record;
if (i == join->const_tables)
{
if (tab->select && tab->select->quick)
{
if (statistics)
statistic_increment(select_range_count, &LOCK_status);
}
else
{
join->thd->server_status|=SERVER_QUERY_NO_INDEX_USED;
if (statistics)
statistic_increment(select_scan_count, &LOCK_status);
}
}
else
{
if (tab->select && tab->select->quick)
{
if (statistics)
statistic_increment(select_full_range_join_count, &LOCK_status);
}
else
{
join->thd->server_status|=SERVER_QUERY_NO_INDEX_USED;
if (statistics)
statistic_increment(select_full_join_count, &LOCK_status);
}
}
if (!table->no_keyread)
{
if (tab->select && tab->select->quick &&
table->used_keys.is_set(tab->select->quick->index))
{
table->key_read=1;
table->file->extra(HA_EXTRA_KEYREAD);
}
else if (!table->used_keys.is_clear_all() &&
!(tab->select && tab->select->quick))
{ // Only read index tree
tab->index=find_shortest_key(table, & table->used_keys);
tab->read_first_record= join_read_first;
tab->type=JT_NEXT; // Read with index_first / index_next
}
}
}
break;
default:
DBUG_PRINT("error",("Table type %d found",tab->type)); /* purecov: deadcode */
break; /* purecov: deadcode */
case JT_UNKNOWN:
case JT_MAYBE_REF:
abort(); /* purecov: deadcode */
}
}
join->join_tab[join->tables-1].next_select=0; /* Set by do_select */
DBUG_VOID_RETURN;
}
/*
Give error if we some tables are done with a full join
SYNOPSIS
error_if_full_join()
join Join condition
USAGE
This is used by multi_table_update and multi_table_delete when running
in safe mode
RETURN VALUES
0 ok
1 Error (full join used)
*/
bool error_if_full_join(JOIN *join)
{
for (JOIN_TAB *tab=join->join_tab, *end=join->join_tab+join->tables;
tab < end;
tab++)
{
if (tab->type == JT_ALL && (!tab->select || !tab->select->quick))
{
my_error(ER_UPDATE_WITHOUT_KEY_IN_SAFE_MODE,MYF(0));
return(1);
}
}
return(0);
}
/*
cleanup JOIN_TAB
SYNOPSIS
JOIN_TAB::cleanup()
*/
void JOIN_TAB::cleanup()
{
delete select;
select= 0;
delete quick;
quick= 0;
x_free(cache.buff);
cache.buff= 0;
if (table)
{
if (table->key_read)
{
table->key_read= 0;
table->file->extra(HA_EXTRA_NO_KEYREAD);
}
table->file->ha_index_or_rnd_end();
/*
We need to reset this for next select
(Tested in part_of_refkey)
*/
table->reginfo.join_tab= 0;
}
end_read_record(&read_record);
}
/*
Free resources of given join
SYNOPSIS
JOIN::join_free()
fill - true if we should free all resources, call with full==1 should be
last, before it this function can be called with full==0
NOTE: with subquery this function definitely will be called several times,
but even for simple query it can be called several times.
*/
void
JOIN::join_free(bool full)
{
JOIN_TAB *tab,*end;
DBUG_ENTER("JOIN::join_free");
full= full || (!select_lex->uncacheable &&
!thd->lex->subqueries &&
!thd->lex->describe); // do not cleanup too early on EXPLAIN
if (table)
{
/*
Only a sorted table may be cached. This sorted table is always the
first non const table in join->table
*/
if (tables > const_tables) // Test for not-const tables
{
free_io_cache(table[const_tables]);
filesort_free_buffers(table[const_tables]);
}
for (SELECT_LEX_UNIT *unit= select_lex->first_inner_unit(); unit;
unit= unit->next_unit())
{
JOIN *join;
for (SELECT_LEX *sl= unit->first_select_in_union(); sl;
sl= sl->next_select())
if ((join= sl->join))
join->join_free(full);
}
if (full)
{
for (tab= join_tab, end= tab+tables; tab != end; tab++)
tab->cleanup();
table= 0;
tables= 0;
}
else
{
for (tab= join_tab, end= tab+tables; tab != end; tab++)
{
if (tab->table)
tab->table->file->ha_index_or_rnd_end();
}
}
}
/*
We are not using tables anymore
Unlock all tables. We may be in an INSERT .... SELECT statement.
*/
if (full && lock && thd->lock && !(select_options & SELECT_NO_UNLOCK) &&
!select_lex->subquery_in_having)
{
// TODO: unlock tables even if the join isn't top level select in the tree
if (select_lex == (thd->lex->unit.fake_select_lex ?
thd->lex->unit.fake_select_lex : &thd->lex->select_lex))
{
mysql_unlock_read_tables(thd, lock); // Don't free join->lock
lock=0;
}
}
if (full)
{
group_fields.delete_elements();
/*
We can't call delete_elements() on copy_funcs as this will cause
problems in free_elements() as some of the elements are then deleted.
*/
tmp_table_param.copy_funcs.empty();
tmp_table_param.cleanup();
}
DBUG_VOID_RETURN;
}
/*****************************************************************************
Remove the following expressions from ORDER BY and GROUP BY:
Constant expressions
Expression that only uses tables that are of type EQ_REF and the reference
is in the ORDER list or if all refereed tables are of the above type.
In the following, the X field can be removed:
SELECT * FROM t1,t2 WHERE t1.a=t2.a ORDER BY t1.a,t2.X
SELECT * FROM t1,t2,t3 WHERE t1.a=t2.a AND t2.b=t3.b ORDER BY t1.a,t3.X
These can't be optimized:
SELECT * FROM t1,t2 WHERE t1.a=t2.a ORDER BY t2.X,t1.a
SELECT * FROM t1,t2 WHERE t1.a=t2.a AND t1.b=t2.b ORDER BY t1.a,t2.c
SELECT * FROM t1,t2 WHERE t1.a=t2.a ORDER BY t2.b,t1.a
*****************************************************************************/
static bool
eq_ref_table(JOIN *join, ORDER *start_order, JOIN_TAB *tab)
{
if (tab->cached_eq_ref_table) // If cached
return tab->eq_ref_table;
tab->cached_eq_ref_table=1;
if (tab->type == JT_CONST) // We can skip const tables
return (tab->eq_ref_table=1); /* purecov: inspected */
if (tab->type != JT_EQ_REF || tab->table->maybe_null)
return (tab->eq_ref_table=0); // We must use this
Item **ref_item=tab->ref.items;
Item **end=ref_item+tab->ref.key_parts;
uint found=0;
table_map map=tab->table->map;
for (; ref_item != end ; ref_item++)
{
if (! (*ref_item)->const_item())
{ // Not a const ref
ORDER *order;
for (order=start_order ; order ; order=order->next)
{
if ((*ref_item)->eq(order->item[0],0))
break;
}
if (order)
{
found++;
DBUG_ASSERT(!(order->used & map));
order->used|=map;
continue; // Used in ORDER BY
}
if (!only_eq_ref_tables(join,start_order, (*ref_item)->used_tables()))
return (tab->eq_ref_table=0);
}
}
/* Check that there was no reference to table before sort order */
for (; found && start_order ; start_order=start_order->next)
{
if (start_order->used & map)
{
found--;
continue;
}
if (start_order->depend_map & map)
return (tab->eq_ref_table=0);
}
return tab->eq_ref_table=1;
}
static bool
only_eq_ref_tables(JOIN *join,ORDER *order,table_map tables)
{
if (specialflag & SPECIAL_SAFE_MODE)
return 0; // skip this optimize /* purecov: inspected */
for (JOIN_TAB **tab=join->map2table ; tables ; tab++, tables>>=1)
{
if (tables & 1 && !eq_ref_table(join, order, *tab))
return 0;
}
return 1;
}
/* Update the dependency map for the tables */
static void update_depend_map(JOIN *join)
{
JOIN_TAB *join_tab=join->join_tab, *end=join_tab+join->tables;
for (; join_tab != end ; join_tab++)
{
TABLE_REF *ref= &join_tab->ref;
table_map depend_map=0;
Item **item=ref->items;
uint i;
for (i=0 ; i < ref->key_parts ; i++,item++)
depend_map|=(*item)->used_tables();
ref->depend_map=depend_map & ~OUTER_REF_TABLE_BIT;
depend_map&= ~OUTER_REF_TABLE_BIT;
for (JOIN_TAB **tab=join->map2table;
depend_map ;
tab++,depend_map>>=1 )
{
if (depend_map & 1)
ref->depend_map|=(*tab)->ref.depend_map;
}
}
}
/* Update the dependency map for the sort order */
static void update_depend_map(JOIN *join, ORDER *order)
{
for (; order ; order=order->next)
{
table_map depend_map;
order->item[0]->update_used_tables();
order->depend_map=depend_map=order->item[0]->used_tables();
// Not item_sum(), RAND() and no reference to table outside of sub select
if (!(order->depend_map & (OUTER_REF_TABLE_BIT | RAND_TABLE_BIT)))
{
for (JOIN_TAB **tab=join->map2table;
depend_map ;
tab++, depend_map>>=1)
{
if (depend_map & 1)
order->depend_map|=(*tab)->ref.depend_map;
}
}
}
}
/*
Remove all constants and check if ORDER only contains simple expressions
SYNOPSIS
remove_const()
join Join handler
first_order List of SORT or GROUP order
cond WHERE statement
change_list Set to 1 if we should remove things from list
If this is not set, then only simple_order is
calculated
simple_order Set to 1 if we are only using simple expressions
RETURN
Returns new sort order
simple_order is set to 1 if sort_order only uses fields from head table
and the head table is not a LEFT JOIN table
*/
static ORDER *
remove_const(JOIN *join,ORDER *first_order, COND *cond,
bool change_list, bool *simple_order)
{
if (join->tables == join->const_tables)
return change_list ? 0 : first_order; // No need to sort
ORDER *order,**prev_ptr;
table_map first_table= join->join_tab[join->const_tables].table->map;
table_map not_const_tables= ~join->const_table_map;
table_map ref;
DBUG_ENTER("remove_const");
prev_ptr= &first_order;
*simple_order= join->join_tab[join->const_tables].on_expr ? 0 : 1;
/* NOTE: A variable of not_const_tables ^ first_table; breaks gcc 2.7 */
update_depend_map(join, first_order);
for (order=first_order; order ; order=order->next)
{
table_map order_tables=order->item[0]->used_tables();
if (order->item[0]->with_sum_func)
*simple_order=0; // Must do a temp table to sort
else if (!(order_tables & not_const_tables))
{
DBUG_PRINT("info",("removing: %s", order->item[0]->full_name()));
continue; // skip const item
}
else
{
if (order_tables & (RAND_TABLE_BIT | OUTER_REF_TABLE_BIT))
*simple_order=0;
else
{
Item *comp_item=0;
if (cond && const_expression_in_where(cond,order->item[0], &comp_item))
{
DBUG_PRINT("info",("removing: %s", order->item[0]->full_name()));
continue;
}
if ((ref=order_tables & (not_const_tables ^ first_table)))
{
if (!(order_tables & first_table) &&
only_eq_ref_tables(join,first_order, ref))
{
DBUG_PRINT("info",("removing: %s", order->item[0]->full_name()));
continue;
}
*simple_order=0; // Must do a temp table to sort
}
}
}
if (change_list)
*prev_ptr= order; // use this entry
prev_ptr= &order->next;
}
if (change_list)
*prev_ptr=0;
if (prev_ptr == &first_order) // Nothing to sort/group
*simple_order=1;
DBUG_PRINT("exit",("simple_order: %d",(int) *simple_order));
DBUG_RETURN(first_order);
}
static int
return_zero_rows(JOIN *join, select_result *result,TABLE_LIST *tables,
List<Item> &fields, bool send_row, uint select_options,
const char *info, Item *having, Procedure *procedure,
SELECT_LEX_UNIT *unit)
{
DBUG_ENTER("return_zero_rows");
if (select_options & SELECT_DESCRIBE)
{
select_describe(join, FALSE, FALSE, FALSE, info);
DBUG_RETURN(0);
}
join->join_free(0);
if (send_row)
{
for (TABLE_LIST *table=tables; table ; table=table->next)
mark_as_null_row(table->table); // All fields are NULL
if (having && having->val_int() == 0)
send_row=0;
}
if (!(result->send_fields(fields,1)))
{
if (send_row)
{
List_iterator_fast<Item> it(fields);
Item *item;
while ((item= it++))
item->no_rows_in_result();
result->send_data(fields);
}
result->send_eof(); // Should be safe
}
/* Update results for FOUND_ROWS */
join->thd->limit_found_rows= join->thd->examined_row_count= 0;
DBUG_RETURN(0);
}
static void clear_tables(JOIN *join)
{
for (uint i=0 ; i < join->tables ; i++)
mark_as_null_row(join->table[i]); // All fields are NULL
}
/*****************************************************************************
Make som simple condition optimization:
If there is a test 'field = const' change all refs to 'field' to 'const'
Remove all dummy tests 'item = item', 'const op const'.
Remove all 'item is NULL', when item can never be null!
item->marker should be 0 for all items on entry
Return in cond_value FALSE if condition is impossible (1 = 2)
*****************************************************************************/
class COND_CMP :public ilink {
public:
static void *operator new(size_t size) {return (void*) sql_alloc((uint) size); }
static void operator delete(void *ptr __attribute__((unused)),
size_t size __attribute__((unused))) {} /*lint -e715 */
Item *and_level;
Item_func *cmp_func;
COND_CMP(Item *a,Item_func *b) :and_level(a),cmp_func(b) {}
};
#ifdef __GNUC__
template class I_List<COND_CMP>;
template class I_List_iterator<COND_CMP>;
template class List<Item_func_match>;
template class List_iterator<Item_func_match>;
#endif
/*
change field = field to field = const for each found field = const in the
and_level
*/
static void
change_cond_ref_to_const(THD *thd, I_List<COND_CMP> *save_list,
Item *and_father, Item *cond,
Item *field, Item *value)
{
if (cond->type() == Item::COND_ITEM)
{
bool and_level= ((Item_cond*) cond)->functype() ==
Item_func::COND_AND_FUNC;
List_iterator<Item> li(*((Item_cond*) cond)->argument_list());
Item *item;
while ((item=li++))
change_cond_ref_to_const(thd, save_list,and_level ? cond : item, item,
field, value);
return;
}
if (cond->eq_cmp_result() == Item::COND_OK)
return; // Not a boolean function
Item_bool_func2 *func= (Item_bool_func2*) cond;
Item **args= func->arguments();
Item *left_item= args[0];
Item *right_item= args[1];
Item_func::Functype functype= func->functype();
if (right_item->eq(field,0) && left_item != value &&
(left_item->result_type() != STRING_RESULT ||
value->result_type() != STRING_RESULT ||
left_item->collation.collation == value->collation.collation))
{
Item *tmp=value->new_item();
if (tmp)
{
thd->change_item_tree(args + 1, tmp);
func->update_used_tables();
if ((functype == Item_func::EQ_FUNC || functype == Item_func::EQUAL_FUNC)
&& and_father != cond && !left_item->const_item())
{
cond->marker=1;
COND_CMP *tmp2;
if ((tmp2=new COND_CMP(and_father,func)))
save_list->push_back(tmp2);
}
func->set_cmp_func();
}
}
else if (left_item->eq(field,0) && right_item != value &&
(right_item->result_type() != STRING_RESULT ||
value->result_type() != STRING_RESULT ||
right_item->collation.collation == value->collation.collation))
{
Item *tmp=value->new_item();
if (tmp)
{
thd->change_item_tree(args, tmp);
value= tmp;
func->update_used_tables();
if ((functype == Item_func::EQ_FUNC || functype == Item_func::EQUAL_FUNC)
&& and_father != cond && !right_item->const_item())
{
args[0]= args[1]; // For easy check
thd->change_item_tree(args + 1, value);
cond->marker=1;
COND_CMP *tmp2;
if ((tmp2=new COND_CMP(and_father,func)))
save_list->push_back(tmp2);
}
func->set_cmp_func();
}
}
}
/*
Remove additional condition inserted by IN/ALL/ANY transformation
SYNOPSIS
remove_additional_cond()
conds - condition for processing
RETURN VALUES
new conditions
*/
static Item *remove_additional_cond(Item* conds)
{
if (conds->name == in_additional_cond)
return 0;
if (conds->type() == Item::COND_ITEM)
{
Item_cond *cnd= (Item_cond*) conds;
List_iterator<Item> li(*(cnd->argument_list()));
Item *item;
while ((item= li++))
{
if (item->name == in_additional_cond)
{
li.remove();
if (cnd->argument_list()->elements == 1)
return cnd->argument_list()->head();
return conds;
}
}
}
return conds;
}
static void
propagate_cond_constants(THD *thd, I_List<COND_CMP> *save_list,
COND *and_father, COND *cond)
{
if (cond->type() == Item::COND_ITEM)
{
bool and_level= ((Item_cond*) cond)->functype() ==
Item_func::COND_AND_FUNC;
List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
Item *item;
I_List<COND_CMP> save;
while ((item=li++))
{
propagate_cond_constants(thd, &save,and_level ? cond : item, item);
}
if (and_level)
{ // Handle other found items
I_List_iterator<COND_CMP> cond_itr(save);
COND_CMP *cond_cmp;
while ((cond_cmp=cond_itr++))
{
Item **args= cond_cmp->cmp_func->arguments();
if (!args[0]->const_item())
change_cond_ref_to_const(thd, &save,cond_cmp->and_level,
cond_cmp->and_level, args[0], args[1]);
}
}
}
else if (and_father != cond && !cond->marker) // In a AND group
{
if (cond->type() == Item::FUNC_ITEM &&
(((Item_func*) cond)->functype() == Item_func::EQ_FUNC ||
((Item_func*) cond)->functype() == Item_func::EQUAL_FUNC))
{
Item_func_eq *func=(Item_func_eq*) cond;
Item **args= func->arguments();
bool left_const= args[0]->const_item();
bool right_const= args[1]->const_item();
if (!(left_const && right_const) &&
args[0]->result_type() == args[1]->result_type())
{
if (right_const)
{
resolve_const_item(thd, &args[1], args[0]);
func->update_used_tables();
change_cond_ref_to_const(thd, save_list, and_father, and_father,
args[0], args[1]);
}
else if (left_const)
{
resolve_const_item(thd, &args[0], args[1]);
func->update_used_tables();
change_cond_ref_to_const(thd, save_list, and_father, and_father,
args[1], args[0]);
}
}
}
}
}
static COND *
optimize_cond(THD *thd, COND *conds, Item::cond_result *cond_value)
{
SELECT_LEX *select= thd->lex->current_select;
DBUG_ENTER("optimize_cond");
if (conds)
{
DBUG_EXECUTE("where", print_where(conds, "original"););
/* change field = field to field = const for each found field = const */
propagate_cond_constants(thd, (I_List<COND_CMP> *) 0, conds, conds);
/*
Remove all instances of item == item
Remove all and-levels where CONST item != CONST item
*/
DBUG_EXECUTE("where", print_where(conds, "after const change"););
conds= remove_eq_conds(thd, conds, cond_value);
DBUG_EXECUTE("info", print_where(conds, "after remove"););
}
else
{
*cond_value= Item::COND_TRUE;
select->prep_where= 0;
}
DBUG_RETURN(conds);
}
/*
Remove const and eq items. Return new item, or NULL if no condition
cond_value is set to according:
COND_OK query is possible (field = constant)
COND_TRUE always true ( 1 = 1 )
COND_FALSE always false ( 1 = 2 )
*/
COND *
remove_eq_conds(THD *thd, COND *cond, Item::cond_result *cond_value)
{
if (cond->type() == Item::COND_ITEM)
{
bool and_level= ((Item_cond*) cond)->functype()
== Item_func::COND_AND_FUNC;
List_iterator<Item> li(*((Item_cond*) cond)->argument_list());
Item::cond_result tmp_cond_value;
bool should_fix_fields=0;
*cond_value=Item::COND_UNDEF;
Item *item;
while ((item=li++))
{
Item *new_item=remove_eq_conds(thd, item, &tmp_cond_value);
if (!new_item)
li.remove();
else if (item != new_item)
{
VOID(li.replace(new_item));
should_fix_fields=1;
}
if (*cond_value == Item::COND_UNDEF)
*cond_value=tmp_cond_value;
switch (tmp_cond_value) {
case Item::COND_OK: // Not TRUE or FALSE
if (and_level || *cond_value == Item::COND_FALSE)
*cond_value=tmp_cond_value;
break;
case Item::COND_FALSE:
if (and_level)
{
*cond_value=tmp_cond_value;
return (COND*) 0; // Always false
}
break;
case Item::COND_TRUE:
if (!and_level)
{
*cond_value= tmp_cond_value;
return (COND*) 0; // Always true
}
break;
case Item::COND_UNDEF: // Impossible
break; /* purecov: deadcode */
}
}
if (should_fix_fields)
cond->update_used_tables();
if (!((Item_cond*) cond)->argument_list()->elements ||
*cond_value != Item::COND_OK)
return (COND*) 0;
if (((Item_cond*) cond)->argument_list()->elements == 1)
{ // Remove list
item= ((Item_cond*) cond)->argument_list()->head();
((Item_cond*) cond)->argument_list()->empty();
return item;
}
}
else if (cond->type() == Item::FUNC_ITEM &&
((Item_func*) cond)->functype() == Item_func::ISNULL_FUNC)
{
/*
Handles this special case for some ODBC applications:
The are requesting the row that was just updated with a auto_increment
value with this construct:
SELECT * from table_name where auto_increment_column IS NULL
This will be changed to:
SELECT * from table_name where auto_increment_column = LAST_INSERT_ID
*/
Item_func_isnull *func=(Item_func_isnull*) cond;
Item **args= func->arguments();
if (args[0]->type() == Item::FIELD_ITEM)
{
Field *field=((Item_field*) args[0])->field;
if (field->flags & AUTO_INCREMENT_FLAG && !field->table->maybe_null &&
(thd->options & OPTION_AUTO_IS_NULL) &&
thd->insert_id())
{
#ifdef HAVE_QUERY_CACHE
query_cache_abort(&thd->net);
#endif
COND *new_cond;
if ((new_cond= new Item_func_eq(args[0],
new Item_int("last_insert_id()",
thd->insert_id(),
21))))
{
cond=new_cond;
cond->fix_fields(thd, 0, &cond);
}
thd->insert_id(0); // Clear for next request
}
/* fix to replace 'NULL' dates with '0' (shreeve@uci.edu) */
else if (((field->type() == FIELD_TYPE_DATE) ||
(field->type() == FIELD_TYPE_DATETIME)) &&
(field->flags & NOT_NULL_FLAG) &&
!field->table->maybe_null)
{
COND *new_cond;
if ((new_cond= new Item_func_eq(args[0],new Item_int("0", 0, 2))))
{
cond=new_cond;
cond->fix_fields(thd, 0, &cond);
}
}
}
}
else if (cond->const_item())
{
*cond_value= eval_const_cond(cond) ? Item::COND_TRUE : Item::COND_FALSE;
return (COND*) 0;
}
else if ((*cond_value= cond->eq_cmp_result()) != Item::COND_OK)
{ // boolan compare function
Item *left_item= ((Item_func*) cond)->arguments()[0];
Item *right_item= ((Item_func*) cond)->arguments()[1];
if (left_item->eq(right_item,1))
{
if (!left_item->maybe_null ||
((Item_func*) cond)->functype() == Item_func::EQUAL_FUNC)
return (COND*) 0; // Compare of identical items
}
}
*cond_value=Item::COND_OK;
return cond; // Point at next and level
}
/*
Return 1 if the item is a const value in all the WHERE clause
*/
static bool
const_expression_in_where(COND *cond, Item *comp_item, Item **const_item)
{
if (cond->type() == Item::COND_ITEM)
{
bool and_level= (((Item_cond*) cond)->functype()
== Item_func::COND_AND_FUNC);
List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list());
Item *item;
while ((item=li++))
{
bool res=const_expression_in_where(item, comp_item, const_item);
if (res) // Is a const value
{
if (and_level)
return 1;
}
else if (!and_level)
return 0;
}
return and_level ? 0 : 1;
}
else if (cond->eq_cmp_result() != Item::COND_OK)
{ // boolan compare function
Item_func* func= (Item_func*) cond;
if (func->functype() != Item_func::EQUAL_FUNC &&
func->functype() != Item_func::EQ_FUNC)
return 0;
Item *left_item= ((Item_func*) cond)->arguments()[0];
Item *right_item= ((Item_func*) cond)->arguments()[1];
if (left_item->eq(comp_item,1))
{
if (right_item->const_item())
{
if (*const_item)
return right_item->eq(*const_item, 1);
*const_item=right_item;
return 1;
}
}
else if (right_item->eq(comp_item,1))
{
if (left_item->const_item())
{
if (*const_item)
return left_item->eq(*const_item, 1);
*const_item=left_item;
return 1;
}
}
}
return 0;
}
/****************************************************************************
Create internal temporary table
****************************************************************************/
/*
Create field for temporary table from given field
SYNOPSIS
create_tmp_field_from_field()
thd Thread handler
org_field field from which new field will be created
name New field name
item Item to create a field for
table Temporary table
item !=NULL if item->result_field should point to new field.
This is relevant for how fill_record() is going to work:
If item != NULL then fill_record() will update
the record in the original table.
If item == NULL then fill_record() will update
the temporary table
convert_blob_length If >0 create a varstring(convert_blob_length) field
instead of blob.
RETURN
0 on error
new_created field
*/
static Field* create_tmp_field_from_field(THD *thd, Field* org_field,
const char *name, TABLE *table,
Item_field *item,
uint convert_blob_length)
{
Field *new_field;
if (convert_blob_length && org_field->flags & BLOB_FLAG)
new_field= new Field_varstring(convert_blob_length, org_field->maybe_null(),
org_field->field_name, table,
org_field->charset());
else
new_field= org_field->new_field(thd->mem_root, table);
if (new_field)
{
if (item)
item->result_field= new_field;
else
new_field->field_name= name;
if (org_field->maybe_null() || (item && item->maybe_null))
new_field->flags&= ~NOT_NULL_FLAG; // Because of outer join
if (org_field->type() == FIELD_TYPE_VAR_STRING)
table->db_create_options|= HA_OPTION_PACK_RECORD;
}
return new_field;
}
/*
Create field for temporary table using type of given item
SYNOPSIS
create_tmp_field_from_item()
thd Thread handler
item Item to create a field for
table Temporary table
copy_func If set and item is a function, store copy of item
in this array
modify_item 1 if item->result_field should point to new item.
This is relevent for how fill_record() is going to
work:
If modify_item is 1 then fill_record() will update
the record in the original table.
If modify_item is 0 then fill_record() will update
the temporary table
convert_blob_length If >0 create a varstring(convert_blob_length) field
instead of blob.
RETURN
0 on error
new_created field
*/
static Field* create_tmp_field_from_item(THD *thd, Item *item, TABLE *table,
Item ***copy_func, bool modify_item,
uint convert_blob_length)
{
bool maybe_null=item->maybe_null;
Field *new_field;
LINT_INIT(new_field);
switch (item->result_type()) {
case REAL_RESULT:
new_field=new Field_double(item->max_length, maybe_null,
item->name, table, item->decimals);
break;
case INT_RESULT:
new_field=new Field_longlong(item->max_length, maybe_null,
item->name, table, item->unsigned_flag);
break;
case STRING_RESULT:
DBUG_ASSERT(item->collation.collation);
enum enum_field_types type;
/*
DATE/TIME fields have STRING_RESULT result type. To preserve
type they needed to be handled separately.
*/
if ((type= item->field_type()) == MYSQL_TYPE_DATETIME ||
type == MYSQL_TYPE_TIME || type == MYSQL_TYPE_DATE)
new_field= item->tmp_table_field_from_field_type(table);
else if (item->max_length/item->collation.collation->mbmaxlen > 255)
{
if (convert_blob_length)
new_field= new Field_varstring(convert_blob_length, maybe_null,
item->name, table,
item->collation.collation);
else
new_field= new Field_blob(item->max_length, maybe_null, item->name,
table, item->collation.collation);
}
else
new_field= new Field_string(item->max_length, maybe_null, item->name,
table, item->collation.collation);
break;
case ROW_RESULT:
default:
// This case should never be choosen
DBUG_ASSERT(0);
new_field= 0; // to satisfy compiler (uninitialized variable)
break;
}
if (copy_func && item->is_result_field())
*((*copy_func)++) = item; // Save for copy_funcs
if (modify_item)
item->set_result_field(new_field);
return new_field;
}
/*
Create field for temporary table
SYNOPSIS
create_tmp_field()
thd Thread handler
table Temporary table
item Item to create a field for
type Type of item (normally item->type)
copy_func If set and item is a function, store copy of item
in this array
from_field if field will be created using other field as example,
pointer example field will be written here
group 1 if we are going to do a relative group by on result
modify_item 1 if item->result_field should point to new item.
This is relevent for how fill_record() is going to
work:
If modify_item is 1 then fill_record() will update
the record in the original table.
If modify_item is 0 then fill_record() will update
the temporary table
convert_blob_length If >0 create a varstring(convert_blob_length) field
instead of blob.
RETURN
0 on error
new_created field
*/
Field *create_tmp_field(THD *thd, TABLE *table,Item *item, Item::Type type,
Item ***copy_func, Field **from_field,
bool group, bool modify_item, uint convert_blob_length)
{
switch (type) {
case Item::SUM_FUNC_ITEM:
{
Item_sum *item_sum=(Item_sum*) item;
bool maybe_null=item_sum->maybe_null;
switch (item_sum->sum_func()) {
case Item_sum::AVG_FUNC: /* Place for sum & count */
if (group)
return new Field_string(sizeof(double)+sizeof(longlong),
0, item->name,table,&my_charset_bin);
else
return new Field_double(item_sum->max_length,maybe_null,
item->name, table, item_sum->decimals);
case Item_sum::VARIANCE_FUNC: /* Place for sum & count */
case Item_sum::STD_FUNC:
if (group)
return new Field_string(sizeof(double)*2+sizeof(longlong),
0, item->name,table,&my_charset_bin);
else
return new Field_double(item_sum->max_length, maybe_null,
item->name,table,item_sum->decimals);
case Item_sum::UNIQUE_USERS_FUNC:
return new Field_long(9,maybe_null,item->name,table,1);
case Item_sum::MIN_FUNC:
case Item_sum::MAX_FUNC:
if (item_sum->args[0]->type() == Item::FIELD_ITEM)
{
*from_field= ((Item_field*) item_sum->args[0])->field;
return create_tmp_field_from_field(thd, *from_field, item->name, table,
NULL, convert_blob_length);
}
/* fall through */
default:
switch (item_sum->result_type()) {
case REAL_RESULT:
return new Field_double(item_sum->max_length,maybe_null,
item->name,table,item_sum->decimals);
case INT_RESULT:
return new Field_longlong(item_sum->max_length,maybe_null,
item->name,table,item->unsigned_flag);
case STRING_RESULT:
if (item_sum->max_length > 255)
{
if (convert_blob_length)
return new Field_varstring(convert_blob_length, maybe_null,
item->name, table,
item->collation.collation);
else
return new Field_blob(item_sum->max_length, maybe_null, item->name,
table, item->collation.collation);
}
return new Field_string(item_sum->max_length,maybe_null,
item->name,table,item->collation.collation);
case ROW_RESULT:
default:
// This case should never be choosen
DBUG_ASSERT(0);
thd->fatal_error();
return 0;
}
}
/* We never come here */
}
case Item::FIELD_ITEM:
case Item::DEFAULT_VALUE_ITEM:
{
Item_field *field= (Item_field*) item;
return create_tmp_field_from_field(thd, (*from_field= field->field),
item->name, table,
modify_item ? (Item_field*) item : NULL,
convert_blob_length);
}
case Item::FUNC_ITEM:
case Item::COND_ITEM:
case Item::FIELD_AVG_ITEM:
case Item::FIELD_STD_ITEM:
case Item::SUBSELECT_ITEM:
/* The following can only happen with 'CREATE TABLE ... SELECT' */
case Item::PROC_ITEM:
case Item::INT_ITEM:
case Item::REAL_ITEM:
case Item::STRING_ITEM:
case Item::REF_ITEM:
case Item::NULL_ITEM:
case Item::VARBIN_ITEM:
return create_tmp_field_from_item(thd, item, table, copy_func, modify_item,
convert_blob_length);
case Item::TYPE_HOLDER:
return ((Item_type_holder *)item)->make_field_by_type(table);
default: // Dosen't have to be stored
return 0;
}
}
/*
Create a temp table according to a field list.
Set distinct if duplicates could be removed
Given fields field pointers are changed to point at tmp_table
for send_fields
*/
TABLE *
create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
ORDER *group, bool distinct, bool save_sum_fields,
ulong select_options, ha_rows rows_limit,
char *table_alias)
{
TABLE *table;
uint i,field_count,reclength,null_count,null_pack_length,
hidden_null_count, hidden_null_pack_length, hidden_field_count,
blob_count,group_null_items;
bool using_unique_constraint=0;
bool not_all_columns= !(select_options & TMP_TABLE_ALL_COLUMNS);
char *tmpname,path[FN_REFLEN];
byte *pos,*group_buff;
uchar *null_flags;
Field **reg_field, **from_field, **blob_field;
Copy_field *copy=0;
KEY *keyinfo;
KEY_PART_INFO *key_part_info;
Item **copy_func;
MI_COLUMNDEF *recinfo;
uint temp_pool_slot=MY_BIT_NONE;
DBUG_ENTER("create_tmp_table");
DBUG_PRINT("enter",("distinct: %d save_sum_fields: %d rows_limit: %lu group: %d",
(int) distinct, (int) save_sum_fields,
(ulong) rows_limit,test(group)));
statistic_increment(created_tmp_tables, &LOCK_status);
if (use_temp_pool)
temp_pool_slot = bitmap_set_next(&temp_pool);
if (temp_pool_slot != MY_BIT_NONE) // we got a slot
sprintf(path, "%s_%lx_%i", tmp_file_prefix,
current_pid, temp_pool_slot);
else // if we run out of slots or we are not using tempool
sprintf(path,"%s%lx_%lx_%x", tmp_file_prefix,current_pid,
thd->thread_id, thd->tmp_table++);
fn_format(path, path, mysql_tmpdir, "", MY_REPLACE_EXT|MY_UNPACK_FILENAME);
if (lower_case_table_names)
my_casedn_str(files_charset_info, path);
if (group)
{
if (!param->quick_group)
group=0; // Can't use group key
else for (ORDER *tmp=group ; tmp ; tmp=tmp->next)
{
(*tmp->item)->marker=4; // Store null in key
if ((*tmp->item)->max_length >= MAX_CHAR_WIDTH)
using_unique_constraint=1;
}
if (param->group_length >= MAX_BLOB_WIDTH)
using_unique_constraint=1;
if (group)
distinct=0; // Can't use distinct
}
field_count=param->field_count+param->func_count+param->sum_func_count;
hidden_field_count=param->hidden_field_count;
if (!my_multi_malloc(MYF(MY_WME),
&table,sizeof(*table),
&reg_field, sizeof(Field*)*(field_count+1),
&blob_field, sizeof(Field*)*(field_count+1),
&from_field, sizeof(Field*)*field_count,
&copy_func,sizeof(*copy_func)*(param->func_count+1),
&param->keyinfo,sizeof(*param->keyinfo),
&key_part_info,
sizeof(*key_part_info)*(param->group_parts+1),
&param->start_recinfo,
sizeof(*param->recinfo)*(field_count*2+4),
&tmpname,(uint) strlen(path)+1,
&group_buff,group && ! using_unique_constraint ?
param->group_length : 0,
NullS))
{
bitmap_clear_bit(&temp_pool, temp_pool_slot);
DBUG_RETURN(NULL); /* purecov: inspected */
}
if (!(param->copy_field=copy=new Copy_field[field_count]))
{
bitmap_clear_bit(&temp_pool, temp_pool_slot);
my_free((gptr) table,MYF(0)); /* purecov: inspected */
DBUG_RETURN(NULL); /* purecov: inspected */
}
param->items_to_copy= copy_func;
strmov(tmpname,path);
/* make table according to fields */
bzero((char*) table,sizeof(*table));
bzero((char*) reg_field,sizeof(Field*)*(field_count+1));
bzero((char*) from_field,sizeof(Field*)*field_count);
table->field=reg_field;
table->blob_field= (Field_blob**) blob_field;
table->real_name=table->path=tmpname;
table->table_name= table_alias;
table->reginfo.lock_type=TL_WRITE; /* Will be updated */
table->db_stat=HA_OPEN_KEYFILE+HA_OPEN_RNDFILE;
table->blob_ptr_size=mi_portable_sizeof_char_ptr;
table->map=1;
table->tmp_table= TMP_TABLE;
table->db_low_byte_first=1; // True for HEAP and MyISAM
table->temp_pool_slot = temp_pool_slot;
table->copy_blobs= 1;
table->in_use= thd;
table->keys_for_keyread.init();
table->keys_in_use.init();
table->read_only_keys.init();
table->quick_keys.init();
table->used_keys.init();
table->keys_in_use_for_query.init();
/* Calculate which type of fields we will store in the temporary table */
reclength=blob_count=null_count=hidden_null_count=group_null_items=0;
param->using_indirect_summary_function=0;
List_iterator_fast<Item> li(fields);
Item *item;
Field **tmp_from_field=from_field;
while ((item=li++))
{
Item::Type type=item->type();
if (not_all_columns)
{
if (item->with_sum_func && type != Item::SUM_FUNC_ITEM)
{
/*
Mark that the we have ignored an item that refers to a summary
function. We need to know this if someone is going to use
DISTINCT on the result.
*/
param->using_indirect_summary_function=1;
continue;
}
if (item->const_item() && (int) hidden_field_count <= 0)
continue; // We don't have to store this
}
if (type == Item::SUM_FUNC_ITEM && !group && !save_sum_fields)
{ /* Can't calc group yet */
((Item_sum*) item)->result_field=0;
for (i=0 ; i < ((Item_sum*) item)->arg_count ; i++)
{
Item **argp= ((Item_sum*) item)->args + i;
Item *arg= *argp;
if (!arg->const_item())
{
Field *new_field=
create_tmp_field(thd, table, arg, arg->type(), &copy_func,
tmp_from_field, group != 0,not_all_columns,
param->convert_blob_length);
if (!new_field)
goto err; // Should be OOM
tmp_from_field++;
*(reg_field++)= new_field;
reclength+=new_field->pack_length();
if (new_field->flags & BLOB_FLAG)
{
*blob_field++= new_field;
blob_count++;
}
thd->change_item_tree(argp, new Item_field(new_field));
if (!(new_field->flags & NOT_NULL_FLAG))
{
null_count++;
/*
new_field->maybe_null() is still false, it will be
changed below. But we have to setup Item_field correctly
*/
(*argp)->maybe_null=1;
}
}
}
}
else
{
/*
The last parameter to create_tmp_field() is a bit tricky:
We need to set it to 0 in union, to get fill_record() to modify the
temporary table.
We need to set it to 1 on multi-table-update and in select to
write rows to the temporary table.
We here distinguish between UNION and multi-table-updates by the fact
that in the later case group is set to the row pointer.
*/
Field *new_field= create_tmp_field(thd, table, item, type, &copy_func,
tmp_from_field, group != 0,
not_all_columns || group !=0,
param->convert_blob_length);
if (!new_field)
{
if (thd->is_fatal_error)
goto err; // Got OOM
continue; // Some kindf of const item
}
if (type == Item::SUM_FUNC_ITEM)
((Item_sum *) item)->result_field= new_field;
tmp_from_field++;
reclength+=new_field->pack_length();
if (!(new_field->flags & NOT_NULL_FLAG))
null_count++;
if (new_field->flags & BLOB_FLAG)
{
*blob_field++= new_field;
blob_count++;
}
if (item->marker == 4 && item->maybe_null)
{
group_null_items++;
new_field->flags|= GROUP_FLAG;
}
*(reg_field++) =new_field;
}
if (!--hidden_field_count)
hidden_null_count=null_count;
}
DBUG_ASSERT(field_count >= (uint) (reg_field - table->field));
field_count= (uint) (reg_field - table->field);
*blob_field= 0; // End marker
/* If result table is small; use a heap */
if (blob_count || using_unique_constraint ||
(select_options & (OPTION_BIG_TABLES | SELECT_SMALL_RESULT)) ==
OPTION_BIG_TABLES ||(select_options & TMP_TABLE_FORCE_MYISAM))
{
table->file=get_new_handler(table,table->db_type=DB_TYPE_MYISAM);
if (group &&
(param->group_parts > table->file->max_key_parts() ||
param->group_length > table->file->max_key_length()))
using_unique_constraint=1;
}
else
{
table->file=get_new_handler(table,table->db_type=DB_TYPE_HEAP);
}
if (!using_unique_constraint)
reclength+= group_null_items; // null flag is stored separately
table->blob_fields=blob_count;
if (blob_count == 0)
{
/* We need to ensure that first byte is not 0 for the delete link */
if (param->hidden_field_count)
hidden_null_count++;
else
null_count++;
}
hidden_null_pack_length=(hidden_null_count+7)/8;
null_pack_length=hidden_null_count+(null_count+7)/8;
reclength+=null_pack_length;
if (!reclength)
reclength=1; // Dummy select
table->fields=field_count;
table->reclength=reclength;
{
uint alloc_length=ALIGN_SIZE(reclength+MI_UNIQUE_HASH_LENGTH+1);
table->rec_buff_length=alloc_length;
if (!(table->record[0]= (byte *) my_malloc(alloc_length*3, MYF(MY_WME))))
goto err;
table->record[1]= table->record[0]+alloc_length;
table->default_values= table->record[1]+alloc_length;
}
copy_func[0]=0; // End marker
recinfo=param->start_recinfo;
null_flags=(uchar*) table->record[0];
pos=table->record[0]+ null_pack_length;
if (null_pack_length)
{
bzero((byte*) recinfo,sizeof(*recinfo));
recinfo->type=FIELD_NORMAL;
recinfo->length=null_pack_length;
recinfo++;
bfill(null_flags,null_pack_length,255); // Set null fields
table->null_flags= (uchar*) table->record[0];
table->null_fields= null_count+ hidden_null_count;
table->null_bytes= null_pack_length;
}
null_count= (blob_count == 0) ? 1 : 0;
hidden_field_count=param->hidden_field_count;
for (i=0,reg_field=table->field; i < field_count; i++,reg_field++,recinfo++)
{
Field *field= *reg_field;
uint length;
bzero((byte*) recinfo,sizeof(*recinfo));
if (!(field->flags & NOT_NULL_FLAG))
{
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;
recinfo++;
bzero((byte*) recinfo,sizeof(*recinfo));
}
else
{
recinfo->null_bit= 1 << (null_count & 7);
recinfo->null_pos= null_count/8;
}
field->move_field((char*) pos,null_flags+null_count/8,
1 << (null_count & 7));
null_count++;
}
else
field->move_field((char*) pos,(uchar*) 0,0);
field->reset();
if (from_field[i])
{ /* Not a table Item */
copy->set(field,from_field[i],save_sum_fields);
copy++;
}
length=field->pack_length();
pos+= length;
/* Make entry for create table */
recinfo->length=length;
if (field->flags & BLOB_FLAG)
recinfo->type= (int) FIELD_BLOB;
else if (!field->zero_pack() &&
(field->type() == FIELD_TYPE_STRING ||
field->type() == FIELD_TYPE_VAR_STRING) &&
length >= 10 && blob_count)
recinfo->type=FIELD_SKIP_ENDSPACE;
else
recinfo->type=FIELD_NORMAL;
if (!--hidden_field_count)
null_count=(null_count+7) & ~7; // move to next byte
// fix table name in field entry
field->table_name= table->table_name;
}
param->copy_field_end=copy;
param->recinfo=recinfo;
store_record(table,default_values); // Make empty default record
if (thd->variables.tmp_table_size == ~(ulong) 0) // No limit
table->max_rows= ~(ha_rows) 0;
else
table->max_rows=(((table->db_type == DB_TYPE_HEAP) ?
min(thd->variables.tmp_table_size,
thd->variables.max_heap_table_size) :
thd->variables.tmp_table_size)/ table->reclength);
set_if_bigger(table->max_rows,1); // For dummy start options
keyinfo=param->keyinfo;
if (group)
{
DBUG_PRINT("info",("Creating group key in temporary table"));
table->group=group; /* Table is grouped by key */
param->group_buff=group_buff;
table->keys=1;
table->uniques= test(using_unique_constraint);
table->key_info=keyinfo;
keyinfo->key_part=key_part_info;
keyinfo->flags=HA_NOSAME;
keyinfo->usable_key_parts=keyinfo->key_parts= param->group_parts;
keyinfo->key_length=0;
keyinfo->rec_per_key=0;
keyinfo->algorithm= HA_KEY_ALG_UNDEF;
for (; group ; group=group->next,key_part_info++)
{
Field *field=(*group->item)->get_tmp_table_field();
bool maybe_null=(*group->item)->maybe_null;
key_part_info->null_bit=0;
key_part_info->field= field;
key_part_info->offset= field->offset();
key_part_info->length= (uint16) field->pack_length();
key_part_info->type= (uint8) field->key_type();
key_part_info->key_type =
((ha_base_keytype) key_part_info->type == HA_KEYTYPE_TEXT ||
(ha_base_keytype) key_part_info->type == HA_KEYTYPE_VARTEXT) ?
0 : FIELDFLAG_BINARY;
if (!using_unique_constraint)
{
group->buff=(char*) group_buff;
if (!(group->field=field->new_field(thd->mem_root,table)))
goto err; /* purecov: inspected */
if (maybe_null)
{
/*
To be able to group on NULL, we reserve place in group_buff
for the NULL flag just before the column.
The field data is after this flag.
The NULL flag is updated by 'end_update()' and 'end_write()'
*/
keyinfo->flags|= HA_NULL_ARE_EQUAL; // def. that NULL == NULL
key_part_info->null_bit=field->null_bit;
key_part_info->null_offset= (uint) (field->null_ptr -
(uchar*) table->record[0]);
group->field->move_field((char*) ++group->buff);
group_buff++;
}
else
group->field->move_field((char*) group_buff);
group_buff+= key_part_info->length;
}
keyinfo->key_length+= key_part_info->length;
}
}
if (distinct)
{
/*
Create an unique key or an unique constraint over all columns
that should be in the result. In the temporary table, there are
'param->hidden_field_count' extra columns, whose null bits are stored
in the first 'hidden_null_pack_length' bytes of the row.
*/
DBUG_PRINT("info",("hidden_field_count: %d", param->hidden_field_count));
null_pack_length-=hidden_null_pack_length;
keyinfo->key_parts= ((field_count-param->hidden_field_count)+
test(null_pack_length));
set_if_smaller(table->max_rows, rows_limit);
param->end_write_records= rows_limit;
table->distinct=1;
table->keys=1;
if (blob_count)
{
using_unique_constraint=1;
table->uniques=1;
}
if (!(key_part_info= (KEY_PART_INFO*)
sql_calloc((keyinfo->key_parts)*sizeof(KEY_PART_INFO))))
goto err;
table->key_info=keyinfo;
keyinfo->key_part=key_part_info;
keyinfo->flags=HA_NOSAME | HA_NULL_ARE_EQUAL;
keyinfo->key_length=(uint16) reclength;
keyinfo->name=(char*) "tmp";
keyinfo->algorithm= HA_KEY_ALG_UNDEF;
keyinfo->rec_per_key=0;
if (null_pack_length)
{
key_part_info->null_bit=0;
key_part_info->offset=hidden_null_pack_length;
key_part_info->length=null_pack_length;
key_part_info->field=new Field_string((char*) table->record[0],
(uint32) key_part_info->length,
(uchar*) 0,
(uint) 0,
Field::NONE,
NullS, table, &my_charset_bin);
key_part_info->key_type=FIELDFLAG_BINARY;
key_part_info->type= HA_KEYTYPE_BINARY;
key_part_info++;
}
/* Create a distinct key over the columns we are going to return */
for (i=param->hidden_field_count, reg_field=table->field + i ;
i < field_count;
i++, reg_field++, key_part_info++)
{
key_part_info->null_bit=0;
key_part_info->field= *reg_field;
key_part_info->offset= (*reg_field)->offset();
key_part_info->length= (uint16) (*reg_field)->pack_length();
key_part_info->type= (uint8) (*reg_field)->key_type();
key_part_info->key_type =
((ha_base_keytype) key_part_info->type == HA_KEYTYPE_TEXT ||
(ha_base_keytype) key_part_info->type == HA_KEYTYPE_VARTEXT) ?
0 : FIELDFLAG_BINARY;
}
}
if (thd->is_fatal_error) // If end of memory
goto err; /* purecov: inspected */
table->db_record_offset=1;
if (table->db_type == DB_TYPE_MYISAM)
{
if (create_myisam_tmp_table(table,param,select_options))
goto err;
}
if (!open_tmp_table(table))
DBUG_RETURN(table);
err:
/*
Hack to ensure that free_blobs() doesn't fail if blob_field is not yet
complete
*/
*table->blob_field= 0;
free_tmp_table(thd,table); /* purecov: inspected */
bitmap_clear_bit(&temp_pool, temp_pool_slot);
DBUG_RETURN(NULL); /* purecov: inspected */
}
static bool open_tmp_table(TABLE *table)
{
int error;
if ((error=table->file->ha_open(table->real_name,O_RDWR,HA_OPEN_TMP_TABLE)))
{
table->file->print_error(error,MYF(0)); /* purecov: inspected */
table->db_stat=0;
return(1);
}
(void) table->file->extra(HA_EXTRA_QUICK); /* Faster */
return(0);
}
static bool create_myisam_tmp_table(TABLE *table,TMP_TABLE_PARAM *param,
ulong options)
{
int error;
MI_KEYDEF keydef;
MI_UNIQUEDEF uniquedef;
KEY *keyinfo=param->keyinfo;
DBUG_ENTER("create_myisam_tmp_table");
if (table->keys)
{ // Get keys for ni_create
bool using_unique_constraint=0;
HA_KEYSEG *seg= (HA_KEYSEG*) sql_calloc(sizeof(*seg) *
keyinfo->key_parts);
if (!seg)
goto err;
if (keyinfo->key_length >= table->file->max_key_length() ||
keyinfo->key_parts > table->file->max_key_parts() ||
table->uniques)
{
/* Can't create a key; Make a unique constraint instead of a key */
table->keys=0;
table->uniques=1;
using_unique_constraint=1;
bzero((char*) &uniquedef,sizeof(uniquedef));
uniquedef.keysegs=keyinfo->key_parts;
uniquedef.seg=seg;
uniquedef.null_are_equal=1;
/* Create extra column for hash value */
bzero((byte*) param->recinfo,sizeof(*param->recinfo));
param->recinfo->type= FIELD_CHECK;
param->recinfo->length=MI_UNIQUE_HASH_LENGTH;
param->recinfo++;
table->reclength+=MI_UNIQUE_HASH_LENGTH;
}
else
{
/* Create an unique key */
bzero((char*) &keydef,sizeof(keydef));
keydef.flag=HA_NOSAME | HA_BINARY_PACK_KEY | HA_PACK_KEY;
keydef.keysegs= keyinfo->key_parts;
keydef.seg= seg;
}
for (uint i=0; i < keyinfo->key_parts ; i++,seg++)
{
Field *field=keyinfo->key_part[i].field;
seg->flag= 0;
seg->language= field->charset()->number;
seg->length= keyinfo->key_part[i].length;
seg->start= keyinfo->key_part[i].offset;
if (field->flags & BLOB_FLAG)
{
seg->type=
((keyinfo->key_part[i].key_type & FIELDFLAG_BINARY) ?
HA_KEYTYPE_VARBINARY : HA_KEYTYPE_VARTEXT);
seg->bit_start=seg->length - table->blob_ptr_size;
seg->flag= HA_BLOB_PART;
seg->length=0; // Whole blob in unique constraint
}
else
{
seg->type=
((keyinfo->key_part[i].key_type & FIELDFLAG_BINARY) ?
HA_KEYTYPE_BINARY : HA_KEYTYPE_TEXT);
if (!(field->flags & ZEROFILL_FLAG) &&
(field->type() == FIELD_TYPE_STRING ||
field->type() == FIELD_TYPE_VAR_STRING) &&
keyinfo->key_part[i].length > 4)
seg->flag|=HA_SPACE_PACK;
}
if (!(field->flags & NOT_NULL_FLAG))
{
seg->null_bit= field->null_bit;
seg->null_pos= (uint) (field->null_ptr - (uchar*) table->record[0]);
/*
We are using a GROUP BY on something that contains NULL
In this case we have to tell MyISAM that two NULL should
on INSERT be compared as equal
*/
if (!using_unique_constraint)
keydef.flag|= HA_NULL_ARE_EQUAL;
}
}
}
MI_CREATE_INFO create_info;
bzero((char*) &create_info,sizeof(create_info));
if ((options & (OPTION_BIG_TABLES | SELECT_SMALL_RESULT)) ==
OPTION_BIG_TABLES)
create_info.data_file_length= ~(ulonglong) 0;
if ((error=mi_create(table->real_name,table->keys,&keydef,
(uint) (param->recinfo-param->start_recinfo),
param->start_recinfo,
table->uniques, &uniquedef,
&create_info,
HA_CREATE_TMP_TABLE)))
{
table->file->print_error(error,MYF(0)); /* purecov: inspected */
table->db_stat=0;
goto err;
}
statistic_increment(created_tmp_disk_tables, &LOCK_status);
table->db_record_offset=1;
DBUG_RETURN(0);
err:
DBUG_RETURN(1);
}
void
free_tmp_table(THD *thd, TABLE *entry)
{
const char *save_proc_info;
DBUG_ENTER("free_tmp_table");
DBUG_PRINT("enter",("table: %s",entry->table_name));
save_proc_info=thd->proc_info;
thd->proc_info="removing tmp table";
free_blobs(entry);
if (entry->file)
{
if (entry->db_stat)
{
(void) entry->file->close();
}
/*
We can't call ha_delete_table here as the table may created in mixed case
here and we have to ensure that delete_table gets the table name in
the original case.
*/
if (!(test_flags & TEST_KEEP_TMP_TABLES) || entry->db_type == DB_TYPE_HEAP)
entry->file->delete_table(entry->real_name);
delete entry->file;
}
/* free blobs */
for (Field **ptr=entry->field ; *ptr ; ptr++)
(*ptr)->free();
my_free((gptr) entry->record[0],MYF(0));
free_io_cache(entry);
bitmap_clear_bit(&temp_pool, entry->temp_pool_slot);
my_free((gptr) entry,MYF(0));
thd->proc_info=save_proc_info;
DBUG_VOID_RETURN;
}
/*
* If a HEAP table gets full, create a MyISAM table and copy all rows to this
*/
bool create_myisam_from_heap(THD *thd, TABLE *table, TMP_TABLE_PARAM *param,
int error, bool ignore_last_dupp_key_error)
{
TABLE new_table;
const char *save_proc_info;
int write_err;
DBUG_ENTER("create_myisam_from_heap");
if (table->db_type != DB_TYPE_HEAP || error != HA_ERR_RECORD_FILE_FULL)
{
table->file->print_error(error,MYF(0));
DBUG_RETURN(1);
}
new_table= *table;
new_table.db_type=DB_TYPE_MYISAM;
if (!(new_table.file=get_new_handler(&new_table,DB_TYPE_MYISAM)))
DBUG_RETURN(1); // End of memory
save_proc_info=thd->proc_info;
thd->proc_info="converting HEAP to MyISAM";
if (create_myisam_tmp_table(&new_table,param,
thd->lex->select_lex.options | thd->options))
goto err2;
if (open_tmp_table(&new_table))
goto err1;
if (table->file->indexes_are_disabled())
new_table.file->disable_indexes(HA_KEY_SWITCH_ALL);
table->file->ha_index_or_rnd_end();
table->file->ha_rnd_init(1);
if (table->no_rows)
{
new_table.file->extra(HA_EXTRA_NO_ROWS);
new_table.no_rows=1;
}
#ifdef TO_BE_DONE_LATER_IN_4_1
/*
To use start_bulk_insert() (which is new in 4.1) we need to find
all places where a corresponding end_bulk_insert() should be put.
*/
table->file->info(HA_STATUS_VARIABLE); /* update table->file->records */
new_table.file->start_bulk_insert(table->file->records);
#else
/* HA_EXTRA_WRITE_CACHE can stay until close, no need to disable it */
new_table.file->extra(HA_EXTRA_WRITE_CACHE);
#endif
/* copy all old rows */
while (!table->file->rnd_next(new_table.record[1]))
{
if ((write_err=new_table.file->write_row(new_table.record[1])))
goto err;
}
/* copy row that filled HEAP table */
if ((write_err=new_table.file->write_row(table->record[0])))
{
if (write_err != HA_ERR_FOUND_DUPP_KEY &&
write_err != HA_ERR_FOUND_DUPP_UNIQUE || !ignore_last_dupp_key_error)
goto err;
}
/* remove heap table and change to use myisam table */
(void) table->file->ha_rnd_end();
(void) table->file->close();
(void) table->file->delete_table(table->real_name);
delete table->file;
table->file=0;
*table =new_table;
table->file->change_table_ptr(table);
thd->proc_info= (!strcmp(save_proc_info,"Copying to tmp table") ?
"Copying to tmp table on disk" : save_proc_info);
DBUG_RETURN(0);
err:
DBUG_PRINT("error",("Got error: %d",write_err));
table->file->print_error(error,MYF(0)); // Give table is full error
(void) table->file->ha_rnd_end();
(void) new_table.file->close();
err1:
new_table.file->delete_table(new_table.real_name);
delete new_table.file;
err2:
thd->proc_info=save_proc_info;
DBUG_RETURN(1);
}
/****************************************************************************
Make a join of all tables and write it on socket or to table
Return: 0 if ok
1 if error is sent
-1 if error should be sent
****************************************************************************/
static int
do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
{
int error= 0;
JOIN_TAB *join_tab;
int (*end_select)(JOIN *, struct st_join_table *,bool);
DBUG_ENTER("do_select");
List<Item> *columns_list= procedure ? &join->procedure_fields_list : fields;
join->procedure=procedure;
/*
Tell the client how many fields there are in a row
*/
if (!table)
join->result->send_fields(*columns_list, 1);
else
{
VOID(table->file->extra(HA_EXTRA_WRITE_CACHE));
empty_record(table);
}
join->tmp_table= table; /* Save for easy recursion */
join->fields= fields;
/* Set up select_end */
if (table)
{
if (table->group && join->tmp_table_param.sum_func_count)
{
if (table->keys)
{
DBUG_PRINT("info",("Using end_update"));
end_select=end_update;
if (!table->file->inited)
table->file->ha_index_init(0);
}
else
{
DBUG_PRINT("info",("Using end_unique_update"));
end_select=end_unique_update;
}
}
else if (join->sort_and_group)
{
DBUG_PRINT("info",("Using end_write_group"));
end_select=end_write_group;
}
else
{
DBUG_PRINT("info",("Using end_write"));
end_select=end_write;
}
}
else
{
if (join->sort_and_group || (join->procedure &&
join->procedure->flags & PROC_GROUP))
end_select=end_send_group;
else
end_select=end_send;
}
join->join_tab[join->tables-1].next_select=end_select;
join_tab=join->join_tab+join->const_tables;
join->send_records=0;
if (join->tables == join->const_tables)
{
/*
HAVING will be chcked after processing aggregate functions,
But WHERE should checkd here (we alredy have read tables)
*/
if (!join->conds || join->conds->val_int())
{
if (!(error=(*end_select)(join,join_tab,0)) || error == -3)
error=(*end_select)(join,join_tab,1);
}
else if (join->send_row_on_empty_set())
error= join->result->send_data(*columns_list);
}
else
{
error= sub_select(join,join_tab,0);
if (error >= 0)
error= sub_select(join,join_tab,1);
if (error == -3)
error= 0; /* select_limit used */
}
if (error >= 0)
{
error=0;
if (!table) // If sending data to client
{
/*
The following will unlock all cursors if the command wasn't an
update command
*/
join->join_free(0); // Unlock all cursors
if (join->result->send_eof())
error= 1; // Don't send error
}
DBUG_PRINT("info",("%ld records output",join->send_records));
}
if (table)
{
int tmp;
if ((tmp=table->file->extra(HA_EXTRA_NO_CACHE)))
{
DBUG_PRINT("error",("extra(HA_EXTRA_NO_CACHE) failed"));
my_errno= tmp;
error= -1;
}
if ((tmp=table->file->ha_index_or_rnd_end()))
{
DBUG_PRINT("error",("ha_index_or_rnd_end() failed"));
my_errno= tmp;
error= -1;
}
if (error == -1)
table->file->print_error(my_errno,MYF(0));
}
#ifndef DBUG_OFF
if (error)
{
DBUG_PRINT("error",("Error: do_select() failed"));
}
#endif
DBUG_RETURN(join->thd->net.report_error ? -1 : error);
}
static int
sub_select_cache(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
{
int error;
if (end_of_records)
{
if ((error=flush_cached_records(join,join_tab,FALSE)) < 0)
return error; /* purecov: inspected */
return sub_select(join,join_tab,end_of_records);
}
if (join->thd->killed) // If aborted by user
{
my_error(ER_SERVER_SHUTDOWN,MYF(0)); /* purecov: inspected */
return -2; /* purecov: inspected */
}
if (join_tab->use_quick != 2 || test_if_quick_select(join_tab) <= 0)
{
if (!store_record_in_cache(&join_tab->cache))
return 0; // There is more room in cache
return flush_cached_records(join,join_tab,FALSE);
}
if ((error=flush_cached_records(join,join_tab,TRUE)) < 0)
return error; /* purecov: inspected */
return sub_select(join,join_tab,end_of_records); /* Use ordinary select */
}
static int
sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
{
join_tab->table->null_row=0;
if (end_of_records)
return (*join_tab->next_select)(join,join_tab+1,end_of_records);
/* Cache variables for faster loop */
int error;
bool found=0;
COND *on_expr=join_tab->on_expr, *select_cond=join_tab->select_cond;
my_bool *report_error= &(join->thd->net.report_error);
if (!(error=(*join_tab->read_first_record)(join_tab)))
{
bool not_exists_optimize= join_tab->table->reginfo.not_exists_optimize;
bool not_used_in_distinct=join_tab->not_used_in_distinct;
ha_rows found_records=join->found_records;
READ_RECORD *info= &join_tab->read_record;
join->thd->row_count= 0;
do
{
if (join->thd->killed) // Aborted by user
{
my_error(ER_SERVER_SHUTDOWN,MYF(0)); /* purecov: inspected */
return -2; /* purecov: inspected */
}
join->examined_rows++;
join->thd->row_count++;
if (!on_expr || on_expr->val_int())
{
found=1;
if (not_exists_optimize)
break; // Searching after not null columns
if (!select_cond || select_cond->val_int())
{
if ((error=(*join_tab->next_select)(join,join_tab+1,0)) < 0)
return error;
/*
Test if this was a SELECT DISTINCT query on a table that
was not in the field list; In this case we can abort if
we found a row, as no new rows can be added to the result.
*/
if (not_used_in_distinct && found_records != join->found_records)
return 0;
}
else
{
/*
This row failed selection, release lock on it.
XXX: There is no table handler in MySQL which makes use of this
call. It's kept from Gemini times. A lot of new code was added
recently (i. e. subselects) without having it in mind.
*/
info->file->unlock_row();
}
}
} while (!(error=info->read_record(info)) && !(*report_error));
}
if (error > 0 || (*report_error)) // Fatal error
return -1;
if (!found && on_expr)
{ // OUTER JOIN
restore_record(join_tab->table,default_values); // Make empty record
mark_as_null_row(join_tab->table); // For group by without error
if (!select_cond || select_cond->val_int())
{
if ((error=(*join_tab->next_select)(join,join_tab+1,0)) < 0)
return error; /* purecov: inspected */
}
}
return 0;
}
static int
flush_cached_records(JOIN *join,JOIN_TAB *join_tab,bool skip_last)
{
int error;
READ_RECORD *info;
if (!join_tab->cache.records)
return 0; /* Nothing to do */
if (skip_last)
(void) store_record_in_cache(&join_tab->cache); // Must save this for later
if (join_tab->use_quick == 2)
{
if (join_tab->select->quick)
{ /* Used quick select last. reset it */
delete join_tab->select->quick;
join_tab->select->quick=0;
}
}
/* read through all records */
if ((error=join_init_read_record(join_tab)))
{
reset_cache_write(&join_tab->cache);
return -error; /* No records or error */
}
for (JOIN_TAB *tmp=join->join_tab; tmp != join_tab ; tmp++)
{
tmp->status=tmp->table->status;
tmp->table->status=0;
}
info= &join_tab->read_record;
do
{
if (join->thd->killed)
{
my_error(ER_SERVER_SHUTDOWN,MYF(0)); /* purecov: inspected */
return -2; // Aborted by user /* purecov: inspected */
}
SQL_SELECT *select=join_tab->select;
if (!error && (!join_tab->cache.select ||
!join_tab->cache.select->skip_record()))
{
uint i;
reset_cache_read(&join_tab->cache);
for (i=(join_tab->cache.records- (skip_last ? 1 : 0)) ; i-- > 0 ;)
{
read_cached_record(join_tab);
if (!select || !select->skip_record())
if ((error=(join_tab->next_select)(join,join_tab+1,0)) < 0)
{
reset_cache_write(&join_tab->cache);
return error; /* purecov: inspected */
}
}
}
} while (!(error=info->read_record(info)));
if (skip_last)
read_cached_record(join_tab); // Restore current record
reset_cache_write(&join_tab->cache);
if (error > 0) // Fatal error
return -1; /* purecov: inspected */
for (JOIN_TAB *tmp2=join->join_tab; tmp2 != join_tab ; tmp2++)
tmp2->table->status=tmp2->status;
return 0;
}
/*****************************************************************************
The different ways to read a record
Returns -1 if row was not found, 0 if row was found and 1 on errors
*****************************************************************************/
/* Help function when we get some an error from the table handler */
int report_error(TABLE *table, int error)
{
if (error == HA_ERR_END_OF_FILE || error == HA_ERR_KEY_NOT_FOUND)
{
table->status= STATUS_GARBAGE;
return -1; // key not found; ok
}
/*
Locking reads can legally return also these errors, do not
print them to the .err log
*/
if (error != HA_ERR_LOCK_DEADLOCK && error != HA_ERR_LOCK_WAIT_TIMEOUT)
sql_print_error("Got error %d when reading table '%s'",
error, table->path);
table->file->print_error(error,MYF(0));
return 1;
}
int safe_index_read(JOIN_TAB *tab)
{
int error;
TABLE *table= tab->table;
if ((error=table->file->index_read(table->record[0],
tab->ref.key_buff,
tab->ref.key_length, HA_READ_KEY_EXACT)))
return report_error(table, error);
return 0;
}
static int
join_read_const_table(JOIN_TAB *tab, POSITION *pos)
{
int error;
DBUG_ENTER("join_read_const_table");
TABLE *table=tab->table;
table->const_table=1;
table->null_row=0;
table->status=STATUS_NO_RECORD;
if (tab->type == JT_SYSTEM)
{
if ((error=join_read_system(tab)))
{ // Info for DESCRIBE
tab->info="const row not found";
/* Mark for EXPLAIN that the row was not found */
pos->records_read=0.0;
if (!table->outer_join || error > 0)
DBUG_RETURN(error);
}
}
else
{
if (!table->key_read && table->used_keys.is_set(tab->ref.key) &&
!table->no_keyread &&
(int) table->reginfo.lock_type <= (int) TL_READ_HIGH_PRIORITY)
{
table->key_read=1;
table->file->extra(HA_EXTRA_KEYREAD);
tab->index= tab->ref.key;
}
if ((error=join_read_const(tab)))
{
tab->info="unique row not found";
/* Mark for EXPLAIN that the row was not found */
pos->records_read=0.0;
if (!table->outer_join || error > 0)
DBUG_RETURN(error);
}
if (table->key_read)
{
table->key_read=0;
table->file->extra(HA_EXTRA_NO_KEYREAD);
}
}
if (tab->on_expr && !table->null_row)
{
if ((table->null_row= test(tab->on_expr->val_int() == 0)))
mark_as_null_row(table);
}
if (!table->null_row)
table->maybe_null=0;
DBUG_RETURN(0);
}
static int
join_read_system(JOIN_TAB *tab)
{
TABLE *table= tab->table;
int error;
if (table->status & STATUS_GARBAGE) // If first read
{
if ((error=table->file->read_first_row(table->record[0],
table->primary_key)))
{
if (error != HA_ERR_END_OF_FILE)
return report_error(table, error);
mark_as_null_row(tab->table);
empty_record(table); // Make empty record
return -1;
}
store_record(table,record[1]);
}
else if (!table->status) // Only happens with left join
restore_record(table,record[1]); // restore old record
table->null_row=0;
return table->status ? -1 : 0;
}
static int
join_read_const(JOIN_TAB *tab)
{
int error;
TABLE *table= tab->table;
if (table->status & STATUS_GARBAGE) // If first read
{
if (cp_buffer_from_ref(tab->join->thd, &tab->ref))
error=HA_ERR_KEY_NOT_FOUND;
else
{
error=table->file->index_read_idx(table->record[0],tab->ref.key,
(byte*) tab->ref.key_buff,
tab->ref.key_length,HA_READ_KEY_EXACT);
}
if (error)
{
mark_as_null_row(tab->table);
empty_record(table);
if (error != HA_ERR_KEY_NOT_FOUND)
return report_error(table, error);
return -1;
}
store_record(table,record[1]);
}
else if (!(table->status & ~STATUS_NULL_ROW)) // Only happens with left join
{
table->status=0;
restore_record(table,record[1]); // restore old record
}
table->null_row=0;
return table->status ? -1 : 0;
}
static int
join_read_key(JOIN_TAB *tab)
{
int error;
TABLE *table= tab->table;
if (!table->file->inited)
table->file->ha_index_init(tab->ref.key);
if (cmp_buffer_with_ref(tab) ||
(table->status & (STATUS_GARBAGE | STATUS_NO_PARENT | STATUS_NULL_ROW)))
{
if (tab->ref.key_err)
{
table->status=STATUS_NOT_FOUND;
return -1;
}
error=table->file->index_read(table->record[0],
tab->ref.key_buff,
tab->ref.key_length,HA_READ_KEY_EXACT);
if (error && error != HA_ERR_KEY_NOT_FOUND)
return report_error(table, error);
}
table->null_row=0;
return table->status ? -1 : 0;
}
static int
join_read_always_key(JOIN_TAB *tab)
{
int error;
TABLE *table= tab->table;
for (uint i= 0 ; i < tab->ref.key_parts ; i++)
{
if ((tab->ref.null_rejecting & 1 << i) && tab->ref.items[i]->is_null())
return -1;
}
if (!table->file->inited)
table->file->ha_index_init(tab->ref.key);
if (cp_buffer_from_ref(tab->join->thd, &tab->ref))
return -1;
if ((error=table->file->index_read(table->record[0],
tab->ref.key_buff,
tab->ref.key_length,HA_READ_KEY_EXACT)))
{
if (error != HA_ERR_KEY_NOT_FOUND)
return report_error(table, error);
return -1; /* purecov: inspected */
}
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 (!table->file->inited)
table->file->ha_index_init(tab->ref.key);
if (cp_buffer_from_ref(tab->join->thd, &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)
return report_error(table, error);
return -1; /* purecov: inspected */
}
return 0;
}
/* ARGSUSED */
static int
join_no_more_records(READ_RECORD *info __attribute__((unused)))
{
return -1;
}
static int
join_read_next_same(READ_RECORD *info)
{
int error;
TABLE *table= info->table;
JOIN_TAB *tab=table->reginfo.join_tab;
if ((error=table->file->index_next_same(table->record[0],
tab->ref.key_buff,
tab->ref.key_length)))
{
if (error != HA_ERR_END_OF_FILE)
return report_error(table, error);
table->status= STATUS_GARBAGE;
return -1;
}
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])))
return report_error(table, error);
if (key_cmp_if_same(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)
{
if (test_if_quick_select(tab) == -1)
return -1; /* No possible records */
return join_init_read_record(tab);
}
static int
test_if_quick_select(JOIN_TAB *tab)
{
delete tab->select->quick;
tab->select->quick=0;
return tab->select->test_quick_select(tab->join->thd, tab->keys,
(table_map) 0, HA_POS_ERROR, 0);
}
static int
join_init_read_record(JOIN_TAB *tab)
{
if (tab->select && tab->select->quick)
tab->select->quick->reset();
init_read_record(&tab->read_record, tab->join->thd, tab->table,
tab->select,1,1);
return (*tab->read_record.read_record)(&tab->read_record);
}
static int
join_read_first(JOIN_TAB *tab)
{
int error;
TABLE *table=tab->table;
if (!table->key_read && table->used_keys.is_set(tab->index) &&
!table->no_keyread)
{
table->key_read=1;
table->file->extra(HA_EXTRA_KEYREAD);
}
tab->table->status=0;
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;
tab->read_record.record=table->record[0];
if (!table->file->inited)
table->file->ha_index_init(tab->index);
if ((error=tab->table->file->index_first(tab->table->record[0])))
{
if (error != HA_ERR_KEY_NOT_FOUND && error != HA_ERR_END_OF_FILE)
report_error(table, error);
return -1;
}
return 0;
}
static int
join_read_next(READ_RECORD *info)
{
int error;
if ((error=info->file->index_next(info->record)))
return report_error(info->table, error);
return 0;
}
static int
join_read_last(JOIN_TAB *tab)
{
TABLE *table=tab->table;
int error;
if (!table->key_read && table->used_keys.is_set(tab->index) &&
!table->no_keyread)
{
table->key_read=1;
table->file->extra(HA_EXTRA_KEYREAD);
}
tab->table->status=0;
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;
tab->read_record.record=table->record[0];
if (!table->file->inited)
table->file->ha_index_init(tab->index);
if ((error= tab->table->file->index_last(tab->table->record[0])))
return report_error(table, error);
return 0;
}
static int
join_read_prev(READ_RECORD *info)
{
int error;
if ((error= info->file->index_prev(info->record)))
return report_error(info->table, error);
return 0;
}
static int
join_ft_read_first(JOIN_TAB *tab)
{
int error;
TABLE *table= tab->table;
if (!table->file->inited)
table->file->ha_index_init(tab->ref.key);
#if NOT_USED_YET
if (cp_buffer_from_ref(tab->join->thd, &tab->ref)) // as ft-key doesn't use store_key's
return -1; // see also FT_SELECT::init()
#endif
table->file->ft_init();
if ((error= table->file->ft_read(table->record[0])))
return report_error(table, error);
return 0;
}
static int
join_ft_read_next(READ_RECORD *info)
{
int error;
if ((error= info->file->ft_read(info->table->record[0])))
return report_error(info->table, error);
return 0;
}
/*
Reading of key with key reference and one part that may be NULL
*/
static int
join_read_always_key_or_null(JOIN_TAB *tab)
{
int res;
/* First read according to key which is NOT NULL */
*tab->ref.null_ref_key= 0; // Clear null byte
if ((res= join_read_always_key(tab)) >= 0)
return res;
/* Then read key with null value */
*tab->ref.null_ref_key= 1; // Set null byte
return safe_index_read(tab);
}
static int
join_read_next_same_or_null(READ_RECORD *info)
{
int error;
if ((error= join_read_next_same(info)) >= 0)
return error;
JOIN_TAB *tab= info->table->reginfo.join_tab;
/* Test if we have already done a read after null key */
if (*tab->ref.null_ref_key)
return -1; // All keys read
*tab->ref.null_ref_key= 1; // Set null byte
return safe_index_read(tab); // then read null keys
}
/*****************************************************************************
The different end of select functions
These functions returns < 0 when end is reached, 0 on ok and > 0 if a
fatal error (like table corruption) was detected
*****************************************************************************/
/* ARGSUSED */
static int
end_send(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
bool end_of_records)
{
DBUG_ENTER("end_send");
if (!end_of_records)
{
int error;
if (join->having && join->having->val_int() == 0)
DBUG_RETURN(0); // Didn't match having
error=0;
if (join->procedure)
error=join->procedure->send_row(join->procedure_fields_list);
else if (join->do_send_rows)
error=join->result->send_data(*join->fields);
if (error)
DBUG_RETURN(-1); /* purecov: inspected */
if (++join->send_records >= join->unit->select_limit_cnt &&
join->do_send_rows)
{
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 &&
!(jt->select && jt->select->quick) &&
!(jt->table->file->table_flags() & HA_NOT_EXACT_COUNT) &&
(jt->ref.key < 0))
{
/* Join over all rows in table; Return number of found rows */
TABLE *table=jt->table;
join->select_options ^= OPTION_FOUND_ROWS;
if (table->sort.record_pointers ||
(table->sort.io_cache && my_b_inited(table->sort.io_cache)))
{
/* Using filesort */
join->send_records= table->sort.found_records;
}
else
{
table->file->info(HA_STATUS_VARIABLE);
join->send_records = table->file->records;
}
}
else
{
join->do_send_rows= 0;
if (join->unit->fake_select_lex)
join->unit->fake_select_lex->select_limit= HA_POS_ERROR;
DBUG_RETURN(0);
}
}
DBUG_RETURN(-3); // Abort nicely
}
}
else
{
if (join->procedure && join->procedure->end_of_records())
DBUG_RETURN(-1);
}
DBUG_RETURN(0);
}
/* ARGSUSED */
static int
end_send_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
bool end_of_records)
{
int idx= -1;
DBUG_ENTER("end_send_group");
if (!join->first_record || end_of_records ||
(idx=test_if_group_changed(join->group_fields)) >= 0)
{
if (join->first_record || (end_of_records && !join->group))
{
if (join->procedure)
join->procedure->end_group();
if (idx < (int) join->send_group_parts)
{
int error=0;
if (join->procedure)
{
if (join->having && join->having->val_int() == 0)
error= -1; // Didn't satisfy having
else
{
if (join->do_send_rows)
error=join->procedure->send_row(*join->fields) ? 1 : 0;
join->send_records++;
}
if (end_of_records && join->procedure->end_of_records())
error= 1; // Fatal error
}
else
{
if (!join->first_record)
{
/* No matching rows for group function */
join->clear();
}
if (join->having && join->having->val_int() == 0)
error= -1; // Didn't satisfy having
else
{
if (join->do_send_rows)
error=join->result->send_data(*join->fields) ? 1 : 0;
join->send_records++;
}
if (join->rollup.state != ROLLUP::STATE_NONE && error <= 0)
{
if (join->rollup_send_data((uint) (idx+1)))
error= 1;
}
}
if (error > 0)
DBUG_RETURN(-1); /* purecov: inspected */
if (end_of_records)
DBUG_RETURN(0);
if (join->send_records >= join->unit->select_limit_cnt &&
join->do_send_rows)
{
if (!(join->select_options & OPTION_FOUND_ROWS))
DBUG_RETURN(-3); // Abort nicely
join->do_send_rows=0;
join->unit->select_limit_cnt = HA_POS_ERROR;
}
}
}
else
{
if (end_of_records)
DBUG_RETURN(0);
join->first_record=1;
VOID(test_if_group_changed(join->group_fields));
}
if (idx < (int) join->send_group_parts)
{
copy_fields(&join->tmp_table_param);
if (init_sum_functions(join->sum_funcs, join->sum_funcs_end[idx+1]))
DBUG_RETURN(-1);
if (join->procedure)
join->procedure->add();
DBUG_RETURN(0);
}
}
if (update_sum_func(join->sum_funcs))
DBUG_RETURN(-1);
if (join->procedure)
join->procedure->add();
DBUG_RETURN(0);
}
/* ARGSUSED */
static int
end_write(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
bool end_of_records)
{
TABLE *table=join->tmp_table;
int error;
DBUG_ENTER("end_write");
if (join->thd->killed) // Aborted by user
{
my_error(ER_SERVER_SHUTDOWN,MYF(0)); /* purecov: inspected */
DBUG_RETURN(-2); /* purecov: inspected */
}
if (!end_of_records)
{
copy_fields(&join->tmp_table_param);
copy_funcs(join->tmp_table_param.items_to_copy);
#ifdef TO_BE_DELETED
if (!table->uniques) // If not unique handling
{
/* Copy null values from group to row */
ORDER *group;
for (group=table->group ; group ; group=group->next)
{
Item *item= *group->item;