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-rw-r--r--sql/sql_select.cc110
1 files changed, 88 insertions, 22 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 22ea300a79a..954080cbc11 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -218,7 +218,8 @@ static COND *make_cond_for_table_from_pred(THD *thd, Item *root_cond,
table_map used_table,
int join_tab_idx_arg,
bool exclude_expensive_cond,
- bool retain_ref_cond);
+ bool retain_ref_cond,
+ bool is_top_and_level);
static Item* part_of_refkey(TABLE *form,Field *field);
uint find_shortest_key(TABLE *table, const key_map *usable_keys);
@@ -4238,7 +4239,7 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
DBUG_RETURN(TRUE); /* purecov: inspected */
{
- ha_rows records= 1;
+ double records= 1;
SELECT_LEX_UNIT *unit= join->select_lex->master_unit();
/* Find an optimal join order of the non-constant tables. */
@@ -4263,10 +4264,11 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
table/view.
*/
for (i= 0; i < join->table_count ; i++)
- records*= join->best_positions[i].records_read ?
- (ha_rows)join->best_positions[i].records_read : 1;
- set_if_smaller(records, unit->select_limit_cnt);
- join->select_lex->increase_derived_records(records);
+ if (double rr= join->best_positions[i].records_read)
+ records= COST_MULT(records, rr);
+ ha_rows rows= records > HA_ROWS_MAX ? HA_ROWS_MAX : (ha_rows) records;
+ set_if_smaller(rows, unit->select_limit_cnt);
+ join->select_lex->increase_derived_records(rows);
}
}
@@ -7392,18 +7394,23 @@ double JOIN::get_examined_rows()
{
double examined_rows;
double prev_fanout= 1;
+ double records;
JOIN_TAB *tab= first_breadth_first_optimization_tab();
JOIN_TAB *prev_tab= tab;
- examined_rows= tab->get_examined_rows();
+ records= tab->get_examined_rows();
while ((tab= next_breadth_first_tab(first_breadth_first_optimization_tab(),
top_table_access_tabs_count, tab)))
{
- prev_fanout *= prev_tab->records_read;
- examined_rows+= tab->get_examined_rows() * prev_fanout;
+ prev_fanout= COST_MULT(prev_fanout, prev_tab->records_read);
+ records=
+ COST_ADD(records,
+ COST_MULT((double) (tab->get_examined_rows()), prev_fanout));
prev_tab= tab;
}
+ examined_rows=
+ records > (double) HA_ROWS_MAX ? HA_ROWS_MAX : (ha_rows) records;
return examined_rows;
}
@@ -9853,12 +9860,6 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
RAND_TABLE_BIT;
}
- /*
- Following force including random expression in last table condition.
- It solve problem with select like SELECT * FROM t1 WHERE rand() > 0.5
- */
- if (tab == join->join_tab + last_top_base_tab_idx)
- current_map|= RAND_TABLE_BIT;
used_tables|=current_map;
if (tab->type == JT_REF && tab->quick &&
@@ -9900,6 +9901,20 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
{
tmp= make_cond_for_table(thd, cond, used_tables, current_map, i,
FALSE, FALSE);
+ if (tab == join->join_tab + last_top_base_tab_idx)
+ {
+ /*
+ This pushes conjunctive conditions of WHERE condition such that:
+ - their used_tables() contain RAND_TABLE_BIT
+ - the conditions does not refer to any fields
+ (such like rand() > 0.5)
+ */
+ table_map rand_table_bit= (table_map) RAND_TABLE_BIT;
+ COND *rand_cond= make_cond_for_table(thd, cond, used_tables,
+ rand_table_bit, -1,
+ FALSE, FALSE);
+ add_cond_and_fix(thd, &tmp, rand_cond);
+ }
}
/* Add conditions added by add_not_null_conds(). */
if (tab->select_cond)
@@ -10235,6 +10250,21 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
current_map,
/*(inner_tab - first_tab)*/ -1,
FALSE, FALSE);
+ if (tab == last_tab)
+ {
+ /*
+ This pushes conjunctive conditions of ON expression of an outer
+ join such that:
+ - their used_tables() contain RAND_TABLE_BIT
+ - the conditions does not refer to any fields
+ (such like rand() > 0.5)
+ */
+ table_map rand_table_bit= (table_map) RAND_TABLE_BIT;
+ COND *rand_cond= make_cond_for_table(thd, on_expr, used_tables2,
+ rand_table_bit, -1,
+ FALSE, FALSE);
+ add_cond_and_fix(thd, &tmp_cond, rand_cond);
+ }
bool is_sjm_lookup_tab= FALSE;
if (inner_tab->bush_children)
{
@@ -11848,6 +11878,8 @@ ha_rows JOIN_TAB::get_examined_rows()
else
examined_rows= records_read;
+ if (examined_rows >= (double) HA_ROWS_MAX)
+ return HA_ROWS_MAX;
return (ha_rows) examined_rows;
}
@@ -20275,7 +20307,7 @@ make_cond_for_table(THD *thd, Item *cond, table_map tables,
return make_cond_for_table_from_pred(thd, cond, cond, tables, used_table,
join_tab_idx_arg,
exclude_expensive_cond,
- retain_ref_cond);
+ retain_ref_cond, true);
}
@@ -20285,9 +20317,12 @@ make_cond_for_table_from_pred(THD *thd, Item *root_cond, Item *cond,
int join_tab_idx_arg,
bool exclude_expensive_cond __attribute__
((unused)),
- bool retain_ref_cond)
+ bool retain_ref_cond,
+ bool is_top_and_level)
{
+ table_map rand_table_bit= (table_map) RAND_TABLE_BIT;
+
if (used_table && !(cond->used_tables() & used_table))
return (COND*) 0; // Already checked
@@ -20303,11 +20338,28 @@ make_cond_for_table_from_pred(THD *thd, Item *root_cond, Item *cond,
Item *item;
while ((item=li++))
{
+ /*
+ Special handling of top level conjuncts with RAND_TABLE_BIT:
+ if such a conjunct contains a reference to a field that is not
+ an outer field then it is pushed to the corresponding table by
+ the same rule as all other conjuncts. Otherwise, if the conjunct
+ is used in WHERE is is pushed to the last joined table, if is it
+ is used in ON condition of an outer join it is pushed into the
+ last inner table of the outer join. Such conjuncts are pushed in
+ a call of make_cond_for_table_from_pred() with the
+ parameter 'used_table' equal to PSEUDO_TABLE_BITS.
+ */
+ if (is_top_and_level && used_table == rand_table_bit &&
+ (item->used_tables() & ~OUTER_REF_TABLE_BIT) != rand_table_bit)
+ {
+ /* The conjunct with RAND_TABLE_BIT has been allready pushed */
+ continue;
+ }
Item *fix=make_cond_for_table_from_pred(thd, root_cond, item,
tables, used_table,
- join_tab_idx_arg,
+ join_tab_idx_arg,
exclude_expensive_cond,
- retain_ref_cond);
+ retain_ref_cond, false);
if (fix)
new_cond->argument_list()->push_back(fix, thd->mem_root);
}
@@ -20331,6 +20383,13 @@ make_cond_for_table_from_pred(THD *thd, Item *root_cond, Item *cond,
}
else
{ // Or list
+ if (is_top_and_level && used_table == rand_table_bit &&
+ (cond->used_tables() & ~OUTER_REF_TABLE_BIT) != rand_table_bit)
+ {
+ /* This top level formula with RAND_TABLE_BIT has been already pushed */
+ return (COND*) 0;
+ }
+
Item_cond_or *new_cond=new (thd->mem_root) Item_cond_or(thd);
if (!new_cond)
return (COND*) 0; // OOM /* purecov: inspected */
@@ -20342,7 +20401,7 @@ make_cond_for_table_from_pred(THD *thd, Item *root_cond, Item *cond,
tables, 0L,
join_tab_idx_arg,
exclude_expensive_cond,
- retain_ref_cond);
+ retain_ref_cond, false);
if (!fix)
return (COND*) 0; // Always true
new_cond->argument_list()->push_back(fix, thd->mem_root);
@@ -20359,6 +20418,13 @@ make_cond_for_table_from_pred(THD *thd, Item *root_cond, Item *cond,
}
}
+ if (is_top_and_level && used_table == rand_table_bit &&
+ (cond->used_tables() & ~OUTER_REF_TABLE_BIT) != rand_table_bit)
+ {
+ /* This top level formula with RAND_TABLE_BIT has been already pushed */
+ return (COND*) 0;
+ }
+
/*
Because the following test takes a while and it can be done
table_count times, we mark each item that we have examined with the result
@@ -24485,10 +24551,10 @@ void JOIN_TAB::save_explain_data(Explain_table_access *eta,
}
else
{
- double examined_rows= get_examined_rows();
+ ha_rows examined_rows= get_examined_rows();
eta->rows_set= true;
- eta->rows= (ha_rows) examined_rows;
+ eta->rows= examined_rows;
/* "filtered" */
float f= 0.0;
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