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Refactor parts of do_select() (JOIN execution).

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This commit is contained in:
konstantin@mysql.com
2005-04-06 21:48:16 +04:00
parent a7c6348192
commit 70aecbb8a4
1 changed files with 57 additions and 36 deletions
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93
sql/sql_select.cc
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@ -111,6 +111,7 @@ static bool const_expression_in_where(COND *conds,Item *item, Item **comp_item);
static bool open_tmp_table(TABLE *table);
static bool create_myisam_tmp_table(TABLE *table,TMP_TABLE_PARAM *param,
ulong options);
static Next_select_func setup_end_select_func(JOIN *join);
static int do_select(JOIN *join,List<Item> *fields,TABLE *tmp_table,
Procedure *proc);
static int sub_select_cache(JOIN *join,JOIN_TAB *join_tab,bool end_of_records);
@ -1638,6 +1639,8 @@ JOIN::exec()
{
thd->proc_info="Sending data";
DBUG_PRINT("info", ("%s", thd->proc_info));
result->send_fields(*curr_fields_list,
Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF);
error= do_select(curr_join, curr_fields_list, NULL, procedure);
thd->limit_found_rows= curr_join->send_records;
thd->examined_row_count= curr_join->examined_rows;
@ -1776,12 +1779,7 @@ Cursor::open(JOIN *join_arg)
thd->server_status&= ~SERVER_STATUS_CURSOR_EXISTS;
/* Prepare JOIN for reading rows. */
Next_select_func end_select= join->sort_and_group || join->procedure &&
join->procedure->flags & PROC_GROUP ?
end_send_group : end_send;
join->join_tab[join->tables-1].next_select= end_select;
join->join_tab[join->tables-1].next_select= setup_end_select_func(join);
join->send_records= 0;
join->fetch_limit= join->unit->offset_limit_cnt;
@ -1802,6 +1800,11 @@ Cursor::open(JOIN *join_arg)
*/
DBUG_ASSERT(join_tab->table->null_row == 0);
/*
There is always at least one record in the table, as otherwise we
wouldn't have opened the cursor. Therefore a failure is the only
reason read_first_record can return not 0.
*/
DBUG_RETURN(join_tab->read_first_record(join_tab));
}
@ -8733,36 +8736,24 @@ bool create_myisam_from_heap(THD *thd, TABLE *table, TMP_TABLE_PARAM *param,
}
/****************************************************************************
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
****************************************************************************/
/*
SYNOPSIS
setup_end_select_func()
join join to setup the function for.
static int
do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
DESCRIPTION
Rows produced by a join sweep may end up in a temporary table or be sent
to a client. Setup the function of the nested loop join algorithm which
handles final fully constructed and matched records.
RETURN
end_select function to use. This function can't fail.
*/
static Next_select_func setup_end_select_func(JOIN *join)
{
int error= 0;
JOIN_TAB *join_tab;
TABLE *table= join->tmp_table;
Next_select_func end_select;
DBUG_ENTER("do_select");
join->procedure=procedure;
/*
Tell the client how many fields there are in a row
*/
if (!table)
join->result->send_fields(*fields,
Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF);
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)
{
@ -8772,8 +8763,6 @@ do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
{
DBUG_PRINT("info",("Using end_update"));
end_select=end_update;
if (!table->file->inited)
table->file->ha_index_init(0);
}
else
{
@ -8807,7 +8796,38 @@ do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
else
end_select= end_send;
}
join->join_tab[join->tables-1].next_select=end_select;
return end_select;
}
/****************************************************************************
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;
DBUG_ENTER("do_select");
join->procedure=procedure;
join->tmp_table= table; /* Save for easy recursion */
join->fields= fields;
if (table)
{
VOID(table->file->extra(HA_EXTRA_WRITE_CACHE));
empty_record(table);
if (table->group && join->tmp_table_param.sum_func_count &&
table->s->keys && !table->file->inited)
table->file->ha_index_init(0);
}
/* Set up select_end */
join->join_tab[join->tables-1].next_select= setup_end_select_func(join);
join_tab=join->join_tab+join->const_tables;
join->send_records=0;
@ -8819,6 +8839,7 @@ do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
*/
if (!join->conds || join->conds->val_int())
{
Next_select_func end_select= join->join_tab[join->tables-1].next_select;
if (!(error=(*end_select)(join,join_tab,0)) || error == -3)
error=(*end_select)(join,join_tab,1);
}