diff options
Diffstat (limited to 'sql/opt_range.cc')
| -rw-r--r-- | sql/opt_range.cc | 105 |
1 files changed, 85 insertions, 20 deletions
diff --git a/sql/opt_range.cc b/sql/opt_range.cc index 7a3a0c94a18..8b07e022ad3 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -11691,7 +11691,8 @@ static bool get_constant_key_infix(KEY *index_info, SEL_ARG *index_range_tree, KEY_PART_INFO **first_non_infix_part); static bool check_group_min_max_predicates(Item *cond, Item_field *min_max_arg_item, - Field::imagetype image_type); + Field::imagetype image_type, + bool *has_min_max_fld, bool *has_other_fld); static void cost_group_min_max(TABLE* table, KEY *index_info, uint used_key_parts, @@ -12031,6 +12032,13 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree, double read_time) else goto next_index; } + /* + This function is called on the precondition that the index is covering. + Therefore if the GROUP BY list contains more elements than the index, + these are duplicates. The GROUP BY list cannot be a prefix of the index. + */ + if (cur_part == end_part && tmp_group) + goto next_index; } /* Check (GA2) if this is a DISTINCT query. @@ -12084,7 +12092,7 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree, double read_time) cur_parts have bits set for only used keyparts. */ ulonglong all_parts, cur_parts; - all_parts= (1<<max_key_part) - 1; + all_parts= (1ULL << max_key_part) - 1; cur_parts= used_key_parts_map.to_ulonglong() >> 1; if (all_parts != cur_parts) goto next_index; @@ -12241,10 +12249,12 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree, double read_time) DBUG_RETURN(NULL); /* Check (SA3) for the where clause. */ + bool has_min_max_fld= false, has_other_fld= false; if (join->conds && min_max_arg_item && !check_group_min_max_predicates(join->conds, min_max_arg_item, (index_info->flags & HA_SPATIAL) ? - Field::itMBR : Field::itRAW)) + Field::itMBR : Field::itRAW, + &has_min_max_fld, &has_other_fld)) DBUG_RETURN(NULL); /* @@ -12292,16 +12302,24 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree, double read_time) SYNOPSIS check_group_min_max_predicates() - cond tree (or subtree) describing all or part of the WHERE - clause being analyzed - min_max_arg_item the field referenced by the MIN/MAX function(s) - min_max_arg_part the keypart of the MIN/MAX argument if any + cond [in] the expression tree being analyzed + min_max_arg [in] the field referenced by the MIN/MAX function(s) + image_type [in] + has_min_max_arg [out] true if the subtree being analyzed references min_max_arg + has_other_arg [out] true if the subtree being analyzed references a column + other min_max_arg DESCRIPTION The function walks recursively over the cond tree representing a WHERE clause, and checks condition (SA3) - if a field is referenced by a MIN/MAX aggregate function, it is referenced only by one of the following - predicates: {=, !=, <, <=, >, >=, between, is null, is not null}. + predicates $FUNC$: + {=, !=, <, <=, >, >=, between, is [not] null, multiple equal}. + In addition the function checks that the WHERE condition is equivalent to + "cond1 AND cond2" where : + cond1 - does not use min_max_column at all. + cond2 - is an AND/OR tree with leaves in form + "$FUNC$(min_max_column[, const])". RETURN TRUE if cond passes the test @@ -12310,7 +12328,8 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree, double read_time) static bool check_group_min_max_predicates(Item *cond, Item_field *min_max_arg_item, - Field::imagetype image_type) + Field::imagetype image_type, + bool *has_min_max_arg, bool *has_other_arg) { DBUG_ENTER("check_group_min_max_predicates"); DBUG_ASSERT(cond && min_max_arg_item); @@ -12322,12 +12341,24 @@ check_group_min_max_predicates(Item *cond, Item_field *min_max_arg_item, DBUG_PRINT("info", ("Analyzing: %s", ((Item_func*) cond)->func_name())); List_iterator_fast<Item> li(*((Item_cond*) cond)->argument_list()); Item *and_or_arg; + Item_func::Functype func_type= ((Item_cond*) cond)->functype(); + bool has_min_max= false, has_other= false; while ((and_or_arg= li++)) { - if (!check_group_min_max_predicates(and_or_arg, min_max_arg_item, - image_type)) + /* + The WHERE clause doesn't pass the condition if: + (1) any subtree doesn't pass the condition or + (2) the subtree passes the test, but it is an OR and it references both + the min/max argument and other columns. + */ + if (!check_group_min_max_predicates(and_or_arg, min_max_arg_item, //1 + image_type, + &has_min_max, &has_other) || + (func_type == Item_func::COND_OR_FUNC && has_min_max && has_other))//2 DBUG_RETURN(FALSE); } + *has_min_max_arg= has_min_max || *has_min_max_arg; + *has_other_arg= has_other || *has_other_arg; DBUG_RETURN(TRUE); } @@ -12361,6 +12392,10 @@ check_group_min_max_predicates(Item *cond, Item_field *min_max_arg_item, if (cond_type == Item::FIELD_ITEM) { DBUG_PRINT("info", ("Analyzing: %s", cond->full_name())); + if (min_max_arg_item->eq((Item_field*)cond, 1)) + *has_min_max_arg= true; + else + *has_other_arg= true; DBUG_RETURN(TRUE); } @@ -12369,9 +12404,33 @@ check_group_min_max_predicates(Item *cond, Item_field *min_max_arg_item, /* Test if cond references only group-by or non-group fields. */ Item_func *pred= (Item_func*) cond; + Item_func::Functype pred_type= pred->functype(); + DBUG_PRINT("info", ("Analyzing: %s", pred->func_name())); + if (pred_type == Item_func::MULT_EQUAL_FUNC) + { + /* + Check that each field in a multiple equality is either a constant or + it is a reference to the min/max argument, or it doesn't contain the + min/max argument at all. + */ + Item_equal_fields_iterator eq_it(*((Item_equal*)pred)); + Item *eq_item; + bool has_min_max= false, has_other= false; + while ((eq_item= eq_it++)) + { + if (min_max_arg_item->eq(eq_item->real_item(), 1)) + has_min_max= true; + else + has_other= true; + } + *has_min_max_arg= has_min_max || *has_min_max_arg; + *has_other_arg= has_other || *has_other_arg; + DBUG_RETURN(!(has_min_max && has_other)); + } + Item **arguments= pred->arguments(); Item *cur_arg; - DBUG_PRINT("info", ("Analyzing: %s", pred->func_name())); + bool has_min_max= false, has_other= false; for (uint arg_idx= 0; arg_idx < pred->argument_count (); arg_idx++) { cur_arg= arguments[arg_idx]->real_item(); @@ -12380,11 +12439,11 @@ check_group_min_max_predicates(Item *cond, Item_field *min_max_arg_item, { if (min_max_arg_item->eq(cur_arg, 1)) { - /* - If pred references the MIN/MAX argument, check whether pred is a range - condition that compares the MIN/MAX argument with a constant. - */ - Item_func::Functype pred_type= pred->functype(); + has_min_max= true; + /* + If pred references the MIN/MAX argument, check whether pred is a range + condition that compares the MIN/MAX argument with a constant. + */ if (pred_type != Item_func::EQUAL_FUNC && pred_type != Item_func::LT_FUNC && pred_type != Item_func::LE_FUNC && @@ -12424,14 +12483,16 @@ check_group_min_max_predicates(Item *cond, Item_field *min_max_arg_item, min_max_arg_item->field->cmp_type() != args[1]->result_type()))) DBUG_RETURN(FALSE); } + else + has_other= true; } else if (cur_arg->type() == Item::FUNC_ITEM) { - if (!check_group_min_max_predicates(cur_arg, min_max_arg_item, - image_type)) + if (!check_group_min_max_predicates(cur_arg, min_max_arg_item, image_type, + &has_min_max, &has_other)) DBUG_RETURN(FALSE); } - else if (cur_arg->const_item()) + else if (cur_arg->const_item() && !cur_arg->is_expensive()) { /* For predicates of the form "const OP expr" we also have to check 'expr' @@ -12441,7 +12502,11 @@ check_group_min_max_predicates(Item *cond, Item_field *min_max_arg_item, } else DBUG_RETURN(FALSE); + if(has_min_max && has_other) + DBUG_RETURN(FALSE); } + *has_min_max_arg= has_min_max || *has_min_max_arg; + *has_other_arg= has_other || *has_other_arg; DBUG_RETURN(TRUE); } |