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MWL#89

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Merge with 5.3
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unknown
2011-05-02 21:59:16 +03:00
parent 8ac88c88f0 0f4236659c
commit 5dc11616b2
74 changed files with 9245 additions and 1677 deletions
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93
sql/sql_select.h
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@ -603,8 +603,53 @@ inline bool sj_is_materialize_strategy(uint strategy)
class JOIN :public Sql_alloc
{
private:
JOIN(const JOIN &rhs); /**< not implemented */
JOIN& operator=(const JOIN &rhs); /**< not implemented */
protected:
/**
The subset of the state of a JOIN that represents an optimized query
execution plan. Allows saving/restoring different plans for the same query.
*/
class Query_plan_state {
public:
DYNAMIC_ARRAY keyuse; /* Copy of the JOIN::keyuse array. */
POSITION best_positions[MAX_TABLES+1]; /* Copy of JOIN::best_positions */
/* Copies of the JOIN_TAB::keyuse pointers for each JOIN_TAB. */
KEYUSE *join_tab_keyuse[MAX_TABLES];
/* Copies of JOIN_TAB::checked_keys for each JOIN_TAB. */
key_map join_tab_checked_keys[MAX_TABLES];
public:
Query_plan_state()
{
keyuse.elements= 0;
keyuse.buffer= NULL;
}
Query_plan_state(JOIN *join);
~Query_plan_state()
{
delete_dynamic(&keyuse);
}
};
/* Results of reoptimizing a JOIN via JOIN::reoptimize(). */
enum enum_reopt_result {
REOPT_NEW_PLAN, /* there is a new reoptimized plan */
REOPT_OLD_PLAN, /* no new improved plan can be found, use the old one */
REOPT_ERROR, /* an irrecovarable error occured during reoptimization */
REOPT_NONE /* not yet reoptimized */
};
/* Support for plan reoptimization with rewritten conditions. */
enum_reopt_result reoptimize(Item *added_where, table_map join_tables,
Query_plan_state *save_to);
void save_query_plan(Query_plan_state *save_to);
void restore_query_plan(Query_plan_state *restore_from);
/* Choose a subquery plan for a table-less subquery. */
bool choose_tableless_subquery_plan();
public:
JOIN_TAB *join_tab,**best_ref;
JOIN_TAB **map2table; ///< mapping between table indexes and JOIN_TABs
@ -702,6 +747,13 @@ public:
account the changes made by test_if_skip_sort_order()).
*/
double best_read;
/*
Estimated result rows (fanout) of the whole query. If this is a subquery
that is reexecuted multiple times, this value includes the estiamted # of
reexecutions. This value is equal to the multiplication of all
join->positions[i].records_read of a JOIN.
*/
double record_count;
List<Item> *fields;
List<Cached_item> group_fields, group_fields_cache;
TABLE *tmp_table;
@ -815,6 +867,19 @@ public:
List<TABLE_LIST> *join_list; ///< list of joined tables in reverse order
COND_EQUAL *cond_equal;
COND_EQUAL *having_equal;
/*
Constant codition computed during optimization, but evaluated during
join execution. Typically expensive conditions that should not be
evaluated at optimization time.
*/
Item *exec_const_cond;
/*
Constant ORDER and/or GROUP expressions that contain subqueries. Such
expressions need to evaluated to verify that the subquery indeed
returns a single row. The evaluation of such expressions is delayed
until query execution.
*/
List<Item> exec_const_order_group_cond;
SQL_SELECT *select; ///<created in optimisation phase
JOIN_TAB *return_tab; ///<used only for outer joins
Item **ref_pointer_array; ///<used pointer reference for this select
@ -825,8 +890,15 @@ public:
bool union_part; ///< this subselect is part of union
bool optimized; ///< flag to avoid double optimization in EXPLAIN
bool initialized; ///< flag to avoid double init_execution calls
Array<Item_in_subselect> sj_subselects;
/*
Additional WHERE and HAVING predicates to be considered for IN=>EXISTS
subquery transformation of a JOIN object.
*/
Item *in_to_exists_where;
Item *in_to_exists_having;
/* Temporary tables used to weed-out semi-join duplicates */
List<TABLE> sj_tmp_tables;
@ -901,8 +973,10 @@ public:
ref_pointer_array_size= 0;
zero_result_cause= 0;
optimized= 0;
initialized= 0;
cond_equal= 0;
having_equal= 0;
exec_const_cond= 0;
group_optimized_away= 0;
no_rows_in_result_called= 0;
@ -917,6 +991,8 @@ public:
no_const_tables= FALSE;
first_select= sub_select;
outer_ref_cond= 0;
in_to_exists_where= NULL;
in_to_exists_having= NULL;
}
int prepare(Item ***rref_pointer_array, TABLE_LIST *tables, uint wind_num,
@ -925,12 +1001,13 @@ public:
SELECT_LEX_UNIT *unit);
int optimize();
int reinit();
int init_execution();
void exec();
int destroy();
void restore_tmp();
bool alloc_func_list();
bool flatten_subqueries();
bool setup_subquery_materialization();
bool optimize_unflattened_subqueries();
bool make_sum_func_list(List<Item> &all_fields, List<Item> &send_fields,
bool before_group_by, bool recompute= FALSE);
@ -966,7 +1043,7 @@ public:
bool init_save_join_tab();
bool send_row_on_empty_set()
{
return (do_send_rows && implicit_grouping &&
return (do_send_rows && implicit_grouping && !group_optimized_away &&
having_value != Item::COND_FALSE);
}
bool change_result(select_result *result);
@ -999,6 +1076,9 @@ public:
return test(allowed_join_cache_types & JOIN_CACHE_HASHED_BIT) &&
max_allowed_join_cache_level > JOIN_CACHE_HASHED_BIT;
}
bool choose_subquery_plan(table_map join_tables);
void get_partial_join_cost(uint n_tables,
double *read_time_arg, double *record_count_arg);
private:
/**
@ -1233,6 +1313,9 @@ protected:
if (!inited)
{
inited=1;
TABLE *table= to_field->table;
my_bitmap_map *old_map= dbug_tmp_use_all_columns(table,
table->write_set);
if ((res= item->save_in_field(to_field, 1)))
{
if (!err)
@ -1244,6 +1327,7 @@ protected:
*/
if (!err && to_field->table->in_use->is_error())
err= 1; /* STORE_KEY_FATAL */
dbug_tmp_restore_column_map(table->write_set, old_map);
}
null_key= to_field->is_null() || item->null_value;
return (err > 2 ? STORE_KEY_FATAL : (store_key_result) err);
@ -1262,9 +1346,7 @@ inline Item * and_items(Item* cond, Item *item)
{
return (cond? (new Item_cond_and(cond, item)) : item);
}
bool choose_plan(JOIN *join,table_map join_tables);
void get_partial_join_cost(JOIN *join, uint n_tables, double *read_time_arg,
double *record_count_arg);
bool choose_plan(JOIN *join, table_map join_tables);
void optimize_wo_join_buffering(JOIN *join, uint first_tab, uint last_tab,
table_map last_remaining_tables,
bool first_alt, uint no_jbuf_before,
@ -1309,5 +1391,6 @@ bool create_internal_tmp_table(TABLE *table, KEY *keyinfo,
ulonglong options);
bool open_tmp_table(TABLE *table);
void setup_tmp_table_column_bitmaps(TABLE *table, uchar *bitmaps);
double prev_record_reads(POSITION *positions, uint idx, table_map found_ref);
#endif /* SQL_SELECT_INCLUDED */