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mysql-5.1-bugteam->mysql-trunk-merge

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This commit is contained in:
Sergey Glukhov
2010-05-27 19:20:10 +04:00
parent eaea879db3 fa3570f96a
commit d7c73e79bd
3 changed files with 137 additions and 10 deletions
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43
sql/sql_select.cc
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@ -2745,31 +2745,53 @@ make_join_statistics(JOIN *join, TABLE_LIST *tables_arg, COND *conds,
/*
Build transitive closure for relation 'to be dependent on'.
This will speed up the plan search for many cases with outer joins,
as well as allow us to catch illegal cross references/
as well as allow us to catch illegal cross references.
Warshall's algorithm is used to build the transitive closure.
As we use bitmaps to represent the relation the complexity
of the algorithm is O((number of tables)^2).
As we may restart the outer loop upto 'table_count' times, the
complexity of the algorithm is O((number of tables)^3).
However, most of the iterations will be shortcircuited when
there are no pedendencies to propogate.
*/
for (i= 0, s= stat ; i < table_count ; i++, s++)
for (i= 0 ; i < table_count ; i++)
{
for (uint j= 0 ; j < table_count ; j++)
uint j;
table= stat[i].table;
if (!table->reginfo.join_tab->dependent)
continue;
/* Add my dependencies to other tables depending on me */
for (j= 0, s= stat ; j < table_count ; j++, s++)
{
table= stat[j].table;
if (s->dependent & table->map)
{
table_map was_dependent= s->dependent;
s->dependent |= table->reginfo.join_tab->dependent;
/*
If we change dependencies for a table we already have
processed: Redo dependency propagation from this table.
*/
if (i > j && s->dependent != was_dependent)
{
i = j-1;
break;
}
}
}
if (outer_join & s->table->map)
s->table->maybe_null= 1;
}
/* Catch illegal cross references for outer joins */
for (i= 0, s= stat ; i < table_count ; i++, s++)
{
/* Catch illegal cross references for outer joins */
if (s->dependent & s->table->map)
{
join->tables=0; // Don't use join->table
my_message(ER_WRONG_OUTER_JOIN, ER(ER_WRONG_OUTER_JOIN), MYF(0));
goto error;
}
if (outer_join & s->table->map)
s->table->maybe_null= 1;
s->key_dependent= s->dependent;
}
}
@ -8822,6 +8844,7 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top)
NESTED_JOIN *nested_join;
TABLE_LIST *prev_table= 0;
List_iterator<TABLE_LIST> li(*join_list);
bool straight_join= test(join->select_options & SELECT_STRAIGHT_JOIN);
DBUG_ENTER("simplify_joins");
/*
@ -8932,7 +8955,7 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top)
if (prev_table)
{
/* The order of tables is reverse: prev_table follows table */
if (prev_table->straight)
if (prev_table->straight || straight_join)
prev_table->dep_tables|= used_tables;
if (prev_table->on_expr)
{