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Merge ramayana.hindu.god:/home/tsmith/m/bk/51

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into  ramayana.hindu.god:/home/tsmith/m/bk/maint/51
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tsmith@ramayana.hindu.god
2007-10-22 14:32:22 -06:00
parent 3f33002fc4 78b61d3a50
commit e347c1413a
24 changed files with 69 additions and 52 deletions
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18
sql/sql_select.cc
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@ -3706,7 +3706,7 @@ update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,JOIN_TAB *join_tab,
{
KEYUSE key_end,*prev,*save_pos,*use;
qsort(keyuse->buffer,keyuse->elements,sizeof(KEYUSE),
my_qsort(keyuse->buffer,keyuse->elements,sizeof(KEYUSE),
(qsort_cmp) sort_keyuse);
bzero((char*) &key_end,sizeof(key_end)); /* Add for easy testing */
@ -4475,8 +4475,9 @@ choose_plan(JOIN *join, table_map join_tables)
Apply heuristic: pre-sort all access plans with respect to the number of
records accessed.
*/
qsort(join->best_ref + join->const_tables, join->tables - join->const_tables,
sizeof(JOIN_TAB*), straight_join?join_tab_cmp_straight:join_tab_cmp);
my_qsort(join->best_ref + join->const_tables,
join->tables - join->const_tables, sizeof(JOIN_TAB*),
straight_join ? join_tab_cmp_straight : join_tab_cmp);
if (straight_join)
{
@ -4523,6 +4524,17 @@ choose_plan(JOIN *join, table_map join_tables)
ptr1 pointer to first JOIN_TAB object
ptr2 pointer to second JOIN_TAB object
NOTES
The order relation implemented by join_tab_cmp() is not transitive,
i.e. it is possible to choose such a, b and c that (a < b) && (b < c)
but (c < a). This implies that result of a sort using the relation
implemented by join_tab_cmp() depends on the order in which
elements are compared, i.e. the result is implementation-specific.
Example:
a: dependent = 0x0 table->map = 0x1 found_records = 3 ptr = 0x907e6b0
b: dependent = 0x0 table->map = 0x2 found_records = 3 ptr = 0x907e838
c: dependent = 0x6 table->map = 0x10 found_records = 2 ptr = 0x907ecd0
RETURN
1 if first is bigger
-1 if second is bigger