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Fixes lp:941889 "JOIN constructors takes a long time in 5.3"

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- Remove all references of MAX_TABLES from JOIN struct and make these dynamic
- Updated Join_plan_state to allocate just as many elements as it's needed


sql/opt_subselect.cc:
  Optimized version of Join_plan_state
sql/sql_select.cc:
  Set join->positions and join->best_positions dynamicly
  Don't call update_virtual_fields() if table->vfield is not set.
sql/sql_select.h:
  Remove all references of MAX_TABLES from JOIN struct and Join_plan_state and make these dynamic
This commit is contained in:
Michael Widenius
2012-03-23 18:18:16 +02:00
parent de1765fb64
commit 8e825a2249
3 changed files with 42 additions and 16 deletions
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32
sql/sql_select.h
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@@ -742,7 +742,7 @@ public:
Information about a position of table within a join order. Used in join
optimization.
*/
typedef struct st_position
typedef struct st_position :public Sql_alloc
{
/* The table that's put into join order */
JOIN_TAB *table;
@@ -844,23 +844,36 @@ protected:
*/
class Join_plan_state {
public:
DYNAMIC_ARRAY keyuse; /* Copy of the JOIN::keyuse array. */
POSITION best_positions[MAX_TABLES+1]; /* Copy of JOIN::best_positions */
DYNAMIC_ARRAY keyuse; /* Copy of the JOIN::keyuse array. */
POSITION *best_positions; /* Copy of JOIN::best_positions */
/* Copies of the JOIN_TAB::keyuse pointers for each JOIN_TAB. */
KEYUSE *join_tab_keyuse[MAX_TABLES];
KEYUSE **join_tab_keyuse;
/* Copies of JOIN_TAB::checked_keys for each JOIN_TAB. */
key_map join_tab_checked_keys[MAX_TABLES];
SJ_MATERIALIZATION_INFO *sj_mat_info[MAX_TABLES];
key_map *join_tab_checked_keys;
SJ_MATERIALIZATION_INFO **sj_mat_info;
my_bool error;
public:
Join_plan_state()
Join_plan_state(uint tables) : error(0)
{
keyuse.elements= 0;
keyuse.buffer= NULL;
best_positions= 0; /* To detect errors */
error= my_multi_malloc(MYF(MY_WME),
&best_positions,
sizeof(*best_positions) * (tables + 1),
&join_tab_keyuse,
sizeof(*join_tab_keyuse) * tables,
&join_tab_checked_keys,
sizeof(*join_tab_checked_keys) * tables,
&sj_mat_info,
sizeof(sj_mat_info) * tables,
NullS) == 0;
}
Join_plan_state(JOIN *join);
~Join_plan_state()
{
delete_dynamic(&keyuse);
my_free(best_positions, MYF(0));
}
};
@@ -961,7 +974,7 @@ public:
*/
ha_rows fetch_limit;
/* Finally picked QEP. This is result of join optimization */
POSITION best_positions[MAX_TABLES+1];
POSITION *best_positions;
/******* Join optimization state members start *******/
/*
@@ -971,7 +984,7 @@ public:
TABLE_LIST *emb_sjm_nest;
/* Current join optimization state */
POSITION positions[MAX_TABLES+1];
POSITION *positions;
/*
Bitmap of nested joins embedding the position at the end of the current
@@ -1241,6 +1254,7 @@ public:
exec_const_cond= 0;
group_optimized_away= 0;
no_rows_in_result_called= 0;
positions= best_positions= 0;
all_fields= fields_arg;
if (&fields_list != &fields_arg) /* Avoid valgrind-warning */