1 | #include <Storages/ReadInOrderOptimizer.h> |
---|---|
2 | #include <Storages/MergeTree/MergeTreeData.h> |
3 | #include <Interpreters/AnalyzedJoin.h> |
4 | #include <Functions/IFunction.h> |
5 | |
6 | namespace DB |
7 | { |
8 | |
9 | namespace ErrorCodes |
10 | { |
11 | extern const int LOGICAL_ERROR; |
12 | } |
13 | |
14 | |
15 | ReadInOrderOptimizer::ReadInOrderOptimizer( |
16 | const ManyExpressionActions & elements_actions_, |
17 | const SortDescription & required_sort_description_, |
18 | const SyntaxAnalyzerResultPtr & syntax_result) |
19 | : elements_actions(elements_actions_) |
20 | , required_sort_description(required_sort_description_) |
21 | { |
22 | if (elements_actions.size() != required_sort_description.size()) |
23 | throw Exception("Sizes of sort description and actions are mismatched", ErrorCodes::LOGICAL_ERROR); |
24 | |
25 | /// Do not analyze joined columns. |
26 | /// They may have aliases and come to descriprion as is. |
27 | /// We can mismatch them with order key columns at stage of fetching columns. |
28 | for (const auto & elem : syntax_result->array_join_result_to_source) |
29 | forbidden_columns.insert(elem.first); |
30 | } |
31 | |
32 | InputSortingInfoPtr ReadInOrderOptimizer::getInputOrder(const StoragePtr & storage) const |
33 | { |
34 | const MergeTreeData * merge_tree = dynamic_cast<const MergeTreeData *>(storage.get()); |
35 | if (!merge_tree || !merge_tree->hasSortingKey()) |
36 | return {}; |
37 | |
38 | SortDescription order_key_prefix_descr; |
39 | int read_direction = required_sort_description.at(0).direction; |
40 | |
41 | const auto & sorting_key_columns = merge_tree->getSortingKeyColumns(); |
42 | size_t prefix_size = std::min(required_sort_description.size(), sorting_key_columns.size()); |
43 | |
44 | for (size_t i = 0; i < prefix_size; ++i) |
45 | { |
46 | if (forbidden_columns.count(required_sort_description[i].column_name)) |
47 | break; |
48 | |
49 | /// Optimize in case of exact match with order key element |
50 | /// or in some simple cases when order key element is wrapped into monotonic function. |
51 | int current_direction = required_sort_description[i].direction; |
52 | if (required_sort_description[i].column_name == sorting_key_columns[i] && current_direction == read_direction) |
53 | order_key_prefix_descr.push_back(required_sort_description[i]); |
54 | else |
55 | { |
56 | /// Allow only one simple monotonic functions with one argument |
57 | bool found_function = false; |
58 | for (const auto & action : elements_actions[i]->getActions()) |
59 | { |
60 | if (action.type != ExpressionAction::APPLY_FUNCTION) |
61 | continue; |
62 | |
63 | if (found_function) |
64 | { |
65 | current_direction = 0; |
66 | break; |
67 | } |
68 | else |
69 | found_function = true; |
70 | |
71 | if (action.argument_names.size() != 1 || action.argument_names.at(0) != sorting_key_columns[i]) |
72 | { |
73 | current_direction = 0; |
74 | break; |
75 | } |
76 | |
77 | const auto & func = *action.function_base; |
78 | if (!func.hasInformationAboutMonotonicity()) |
79 | { |
80 | current_direction = 0; |
81 | break; |
82 | } |
83 | |
84 | auto monotonicity = func.getMonotonicityForRange(*func.getArgumentTypes().at(0), {}, {}); |
85 | if (!monotonicity.is_monotonic) |
86 | { |
87 | current_direction = 0; |
88 | break; |
89 | } |
90 | else if (!monotonicity.is_positive) |
91 | current_direction *= -1; |
92 | } |
93 | |
94 | if (!found_function) |
95 | current_direction = 0; |
96 | |
97 | if (!current_direction || (i > 0 && current_direction != read_direction)) |
98 | break; |
99 | |
100 | if (i == 0) |
101 | read_direction = current_direction; |
102 | |
103 | order_key_prefix_descr.push_back(required_sort_description[i]); |
104 | } |
105 | } |
106 | |
107 | if (order_key_prefix_descr.empty()) |
108 | return {}; |
109 | |
110 | return std::make_shared<InputSortingInfo>(std::move(order_key_prefix_descr), read_direction); |
111 | } |
112 | |
113 | } |
114 |