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Ruslan
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@ -1,4 +1,950 @@
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//
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// Created by ruslan on 27.12.2019.
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//
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#include <Core/Settings.h>
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#include <Core/NamesAndTypes.h>
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#include <Interpreters/SyntaxAnalyzer.h>
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#include <Interpreters/InJoinSubqueriesPreprocessor.h>
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#include <Interpreters/LogicalExpressionsOptimizer.h>
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#include <Interpreters/QueryAliasesVisitor.h>
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#include <Interpreters/InterpreterSelectWithUnionQuery.h>
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#include <Interpreters/ArrayJoinedColumnsVisitor.h>
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#include <Interpreters/TranslateQualifiedNamesVisitor.h>
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#include <Interpreters/Context.h>
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#include <Interpreters/MarkTableIdentifiersVisitor.h>
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#include <Interpreters/QueryNormalizer.h>
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#include <Interpreters/ExecuteScalarSubqueriesVisitor.h>
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#include <Interpreters/PredicateExpressionsOptimizer.h>
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#include <Interpreters/CollectJoinOnKeysVisitor.h>
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#include <Interpreters/ExternalDictionariesLoader.h>
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#include <Interpreters/OptimizeIfWithConstantConditionVisitor.h>
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#include <Interpreters/RequiredSourceColumnsVisitor.h>
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#include <Interpreters/GetAggregatesVisitor.h>
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#include <Interpreters/AnalyzedJoin.h>
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#include <Interpreters/ExpressionActions.h> /// getSmallestColumn()
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#include <Interpreters/getTableExpressions.h>
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#include <Interpreters/OptimizeIfChains.h>
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#include <Parsers/ASTExpressionList.h>
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#include <Parsers/ASTFunction.h>
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#include <Parsers/ASTLiteral.h>
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#include <Parsers/ASTOrderByElement.h>
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#include <Parsers/ASTSelectQuery.h>
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#include <Parsers/ASTTablesInSelectQuery.h>
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#include <Parsers/ParserTablesInSelectQuery.h>
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#include <Parsers/parseQuery.h>
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#include <Parsers/queryToString.h>
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#include <DataTypes/NestedUtils.h>
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#include <DataTypes/DataTypeNullable.h>
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#include <IO/WriteHelpers.h>
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#include <Storages/IStorage.h>
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#include <functional>
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namespace DB
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{
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namespace ErrorCodes
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{
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extern const int EMPTY_NESTED_TABLE;
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extern const int LOGICAL_ERROR;
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extern const int INVALID_JOIN_ON_EXPRESSION;
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extern const int EMPTY_LIST_OF_COLUMNS_QUERIED;
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extern const int NOT_IMPLEMENTED;
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extern const int UNKNOWN_IDENTIFIER;
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extern const int EXPECTED_ALL_OR_ANY;
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extern const int ALIAS_REQUIRED;
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}
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namespace
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{
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using LogAST = DebugASTLog<false>; /// set to true to enable logs
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/// Select implementation of countDistinct based on settings.
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/// Important that it is done as query rewrite. It means rewritten query
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/// will be sent to remote servers during distributed query execution,
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/// and on all remote servers, function implementation will be same.
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struct CustomizeFunctionsData
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{
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using TypeToVisit = ASTFunction;
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const String & count_distinct;
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void visit(ASTFunction & func, ASTPtr &)
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{
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if (Poco::toLower(func.name) == "countdistinct")
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func.name = count_distinct;
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}
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};
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using CustomizeFunctionsMatcher = OneTypeMatcher<CustomizeFunctionsData>;
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using CustomizeFunctionsVisitor = InDepthNodeVisitor<CustomizeFunctionsMatcher, true>;
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/// Add columns from storage to source_columns list.
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void collectSourceColumns(const ColumnsDescription & columns, NamesAndTypesList & source_columns, bool add_virtuals)
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{
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auto physical_columns = columns.getAllPhysical();
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if (source_columns.empty())
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source_columns.swap(physical_columns);
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else
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source_columns.insert(source_columns.end(), physical_columns.begin(), physical_columns.end());
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if (add_virtuals)
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{
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const auto & storage_aliases = columns.getAliases();
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const auto & storage_virtuals = columns.getVirtuals();
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source_columns.insert(source_columns.end(), storage_aliases.begin(), storage_aliases.end());
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source_columns.insert(source_columns.end(), storage_virtuals.begin(), storage_virtuals.end());
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}
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}
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std::vector<TableWithColumnNames> getTablesWithColumns(const std::vector<const ASTTableExpression * > & table_expressions,
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const Context & context)
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{
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std::vector<TableWithColumnNames> tables_with_columns = getDatabaseAndTablesWithColumnNames(table_expressions, context);
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auto & settings = context.getSettingsRef();
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if (settings.joined_subquery_requires_alias && tables_with_columns.size() > 1)
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{
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for (auto & pr : tables_with_columns)
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if (pr.table.table.empty() && pr.table.alias.empty())
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throw Exception("Not unique subquery in FROM requires an alias (or joined_subquery_requires_alias=0 to disable restriction).",
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ErrorCodes::ALIAS_REQUIRED);
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}
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return tables_with_columns;
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}
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/// Translate qualified names such as db.table.column, table.column, table_alias.column to names' normal form.
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/// Expand asterisks and qualified asterisks with column names.
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/// There would be columns in normal form & column aliases after translation. Column & column alias would be normalized in QueryNormalizer.
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void translateQualifiedNames(ASTPtr & query, const ASTSelectQuery & select_query, const NameSet & source_columns_set,
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std::vector<TableWithColumnNames> && tables_with_columns)
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{
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LogAST log;
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TranslateQualifiedNamesVisitor::Data visitor_data(source_columns_set, std::move(tables_with_columns));
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TranslateQualifiedNamesVisitor visitor(visitor_data, log.stream());
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visitor.visit(query);
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/// This may happen after expansion of COLUMNS('regexp').
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if (select_query.select()->children.empty())
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throw Exception("Empty list of columns in SELECT query", ErrorCodes::EMPTY_LIST_OF_COLUMNS_QUERIED);
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}
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bool hasArrayJoin(const ASTPtr & ast)
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{
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if (const ASTFunction * function = ast->as<ASTFunction>())
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if (function->name == "arrayJoin")
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return true;
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for (const auto & child : ast->children)
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if (!child->as<ASTSelectQuery>() && hasArrayJoin(child))
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return true;
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return false;
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}
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/// Keep number of columns for 'GLOBAL IN (SELECT 1 AS a, a)'
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void renameDuplicatedColumns(const ASTSelectQuery * select_query)
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{
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ASTs & elements = select_query->select()->children;
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std::set<String> all_column_names;
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std::set<String> assigned_column_names;
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for (auto & expr : elements)
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all_column_names.insert(expr->getAliasOrColumnName());
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for (auto & expr : elements)
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{
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auto name = expr->getAliasOrColumnName();
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if (!assigned_column_names.insert(name).second)
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{
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size_t i = 1;
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while (all_column_names.end() != all_column_names.find(name + "_" + toString(i)))
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++i;
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name = name + "_" + toString(i);
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expr = expr->clone(); /// Cancels fuse of the same expressions in the tree.
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expr->setAlias(name);
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all_column_names.insert(name);
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assigned_column_names.insert(name);
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}
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}
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}
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/// Sometimes we have to calculate more columns in SELECT clause than will be returned from query.
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/// This is the case when we have DISTINCT or arrayJoin: we require more columns in SELECT even if we need less columns in result.
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/// Also we have to remove duplicates in case of GLOBAL subqueries. Their results are placed into tables so duplicates are inpossible.
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void removeUnneededColumnsFromSelectClause(const ASTSelectQuery * select_query, const Names & required_result_columns, bool remove_dups)
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{
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ASTs & elements = select_query->select()->children;
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std::map<String, size_t> required_columns_with_duplicate_count;
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if (!required_result_columns.empty())
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{
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/// Some columns may be queried multiple times, like SELECT x, y, y FROM table.
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for (const auto & name : required_result_columns)
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{
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if (remove_dups)
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required_columns_with_duplicate_count[name] = 1;
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else
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++required_columns_with_duplicate_count[name];
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}
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}
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else if (remove_dups)
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{
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/// Even if we have no requirements there could be duplicates cause of asterisks. SELECT *, t.*
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for (const auto & elem : elements)
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required_columns_with_duplicate_count.emplace(elem->getAliasOrColumnName(), 1);
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}
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else
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return;
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ASTs new_elements;
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new_elements.reserve(elements.size());
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for (const auto & elem : elements)
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{
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String name = elem->getAliasOrColumnName();
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auto it = required_columns_with_duplicate_count.find(name);
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if (required_columns_with_duplicate_count.end() != it && it->second)
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{
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new_elements.push_back(elem);
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--it->second;
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}
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else if (select_query->distinct || hasArrayJoin(elem))
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{
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new_elements.push_back(elem);
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}
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}
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elements = std::move(new_elements);
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}
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/// Replacing scalar subqueries with constant values.
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void executeScalarSubqueries(ASTPtr & query, const Context & context, size_t subquery_depth, Scalars & scalars)
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{
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LogAST log;
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ExecuteScalarSubqueriesVisitor::Data visitor_data{context, subquery_depth, scalars};
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ExecuteScalarSubqueriesVisitor(visitor_data, log.stream()).visit(query);
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}
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/** Calls to these functions in the GROUP BY statement would be
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* replaced by their immediate argument.
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*/
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const std::unordered_set<String> injective_function_names
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{
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"negate",
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"bitNot",
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"reverse",
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"reverseUTF8",
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"toString",
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"toFixedString",
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"IPv4NumToString",
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"IPv4StringToNum",
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"hex",
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"unhex",
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"bitmaskToList",
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"bitmaskToArray",
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"tuple",
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"regionToName",
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"concatAssumeInjective",
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};
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const std::unordered_set<String> possibly_injective_function_names
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{
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"dictGetString",
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"dictGetUInt8",
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"dictGetUInt16",
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"dictGetUInt32",
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"dictGetUInt64",
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"dictGetInt8",
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"dictGetInt16",
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"dictGetInt32",
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"dictGetInt64",
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"dictGetFloat32",
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"dictGetFloat64",
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"dictGetDate",
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"dictGetDateTime"
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};
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/** You can not completely remove GROUP BY. Because if there were no aggregate functions, then it turns out that there will be no aggregation.
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* Instead, leave `GROUP BY const`.
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* Next, see deleting the constants in the analyzeAggregation method.
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*/
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void appendUnusedGroupByColumn(ASTSelectQuery * select_query, const NameSet & source_columns)
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{
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/// You must insert a constant that is not the name of the column in the table. Such a case is rare, but it happens.
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UInt64 unused_column = 0;
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String unused_column_name = toString(unused_column);
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while (source_columns.count(unused_column_name))
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{
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++unused_column;
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unused_column_name = toString(unused_column);
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}
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select_query->setExpression(ASTSelectQuery::Expression::GROUP_BY, std::make_shared<ASTExpressionList>());
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select_query->groupBy()->children.emplace_back(std::make_shared<ASTLiteral>(UInt64(unused_column)));
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}
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/// Eliminates injective function calls and constant expressions from group by statement.
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void optimizeGroupBy(ASTSelectQuery * select_query, const NameSet & source_columns, const Context & context)
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{
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if (!select_query->groupBy())
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{
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// If there is a HAVING clause without GROUP BY, make sure we have some aggregation happen.
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if (select_query->having())
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appendUnusedGroupByColumn(select_query, source_columns);
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return;
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}
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const auto is_literal = [] (const ASTPtr & ast) -> bool
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{
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return ast->as<ASTLiteral>();
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};
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auto & group_exprs = select_query->groupBy()->children;
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/// removes expression at index idx by making it last one and calling .pop_back()
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const auto remove_expr_at_index = [&group_exprs] (const size_t idx)
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{
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if (idx < group_exprs.size() - 1)
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std::swap(group_exprs[idx], group_exprs.back());
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group_exprs.pop_back();
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};
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/// iterate over each GROUP BY expression, eliminate injective function calls and literals
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for (size_t i = 0; i < group_exprs.size();)
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{
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if (const auto * function = group_exprs[i]->as<ASTFunction>())
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{
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/// assert function is injective
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if (possibly_injective_function_names.count(function->name))
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{
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/// do not handle semantic errors here
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if (function->arguments->children.size() < 2)
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{
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++i;
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continue;
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}
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const auto & dict_name = function->arguments->children[0]->as<ASTLiteral &>().value.safeGet<String>();
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const auto & dict_ptr = context.getExternalDictionariesLoader().getDictionary(dict_name);
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const auto & attr_name = function->arguments->children[1]->as<ASTLiteral &>().value.safeGet<String>();
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if (!dict_ptr->isInjective(attr_name))
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{
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++i;
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continue;
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}
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}
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else if (!injective_function_names.count(function->name))
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{
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++i;
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continue;
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}
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/// copy shared pointer to args in order to ensure lifetime
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auto args_ast = function->arguments;
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/** remove function call and take a step back to ensure
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* next iteration does not skip not yet processed data
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*/
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remove_expr_at_index(i);
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/// copy non-literal arguments
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std::remove_copy_if(
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std::begin(args_ast->children), std::end(args_ast->children),
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std::back_inserter(group_exprs), is_literal
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);
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}
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else if (is_literal(group_exprs[i]))
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{
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remove_expr_at_index(i);
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}
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else
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{
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/// if neither a function nor literal - advance to next expression
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++i;
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}
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}
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if (group_exprs.empty())
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appendUnusedGroupByColumn(select_query, source_columns);
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}
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/// Remove duplicate items from ORDER BY.
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void optimizeOrderBy(const ASTSelectQuery * select_query)
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{
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if (!select_query->orderBy())
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return;
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/// Make unique sorting conditions.
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using NameAndLocale = std::pair<String, String>;
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std::set<NameAndLocale> elems_set;
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ASTs & elems = select_query->orderBy()->children;
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ASTs unique_elems;
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unique_elems.reserve(elems.size());
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for (const auto & elem : elems)
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{
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String name = elem->children.front()->getColumnName();
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const auto & order_by_elem = elem->as<ASTOrderByElement &>();
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if (elems_set.emplace(name, order_by_elem.collation ? order_by_elem.collation->getColumnName() : "").second)
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unique_elems.emplace_back(elem);
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}
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if (unique_elems.size() < elems.size())
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elems = std::move(unique_elems);
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}
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/// Remove duplicate items from LIMIT BY.
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void optimizeLimitBy(const ASTSelectQuery * select_query)
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{
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if (!select_query->limitBy())
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return;
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std::set<String> elems_set;
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||||
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||||
ASTs & elems = select_query->limitBy()->children;
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ASTs unique_elems;
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unique_elems.reserve(elems.size());
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for (const auto & elem : elems)
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{
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if (elems_set.emplace(elem->getColumnName()).second)
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unique_elems.emplace_back(elem);
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}
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||||
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if (unique_elems.size() < elems.size())
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elems = std::move(unique_elems);
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}
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/// Remove duplicated columns from USING(...).
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void optimizeUsing(const ASTSelectQuery * select_query)
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{
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if (!select_query->join())
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return;
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const auto * table_join = select_query->join()->table_join->as<ASTTableJoin>();
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if (!(table_join && table_join->using_expression_list))
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return;
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ASTs & expression_list = table_join->using_expression_list->children;
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ASTs uniq_expressions_list;
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std::set<String> expressions_names;
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for (const auto & expression : expression_list)
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||||
{
|
||||
auto expression_name = expression->getAliasOrColumnName();
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||||
if (expressions_names.find(expression_name) == expressions_names.end())
|
||||
{
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||||
uniq_expressions_list.push_back(expression);
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||||
expressions_names.insert(expression_name);
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||||
}
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||||
}
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||||
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||||
if (uniq_expressions_list.size() < expression_list.size())
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expression_list = uniq_expressions_list;
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||||
}
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||||
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||||
void getArrayJoinedColumns(ASTPtr & query, SyntaxAnalyzerResult & result, const ASTSelectQuery * select_query,
|
||||
const NamesAndTypesList & source_columns, const NameSet & source_columns_set)
|
||||
{
|
||||
if (ASTPtr array_join_expression_list = select_query->array_join_expression_list())
|
||||
{
|
||||
ArrayJoinedColumnsVisitor::Data visitor_data{result.aliases,
|
||||
result.array_join_name_to_alias,
|
||||
result.array_join_alias_to_name,
|
||||
result.array_join_result_to_source};
|
||||
ArrayJoinedColumnsVisitor(visitor_data).visit(query);
|
||||
|
||||
/// If the result of ARRAY JOIN is not used, it is necessary to ARRAY-JOIN any column,
|
||||
/// to get the correct number of rows.
|
||||
if (result.array_join_result_to_source.empty())
|
||||
{
|
||||
ASTPtr expr = select_query->array_join_expression_list()->children.at(0);
|
||||
String source_name = expr->getColumnName();
|
||||
String result_name = expr->getAliasOrColumnName();
|
||||
|
||||
/// This is an array.
|
||||
if (!expr->as<ASTIdentifier>() || source_columns_set.count(source_name))
|
||||
{
|
||||
result.array_join_result_to_source[result_name] = source_name;
|
||||
}
|
||||
else /// This is a nested table.
|
||||
{
|
||||
bool found = false;
|
||||
for (const auto & column : source_columns)
|
||||
{
|
||||
auto splitted = Nested::splitName(column.name);
|
||||
if (splitted.first == source_name && !splitted.second.empty())
|
||||
{
|
||||
result.array_join_result_to_source[Nested::concatenateName(result_name, splitted.second)] = column.name;
|
||||
found = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (!found)
|
||||
throw Exception("No columns in nested table " + source_name, ErrorCodes::EMPTY_NESTED_TABLE);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void setJoinStrictness(ASTSelectQuery & select_query, JoinStrictness join_default_strictness, bool old_any, ASTTableJoin & out_table_join)
|
||||
{
|
||||
const ASTTablesInSelectQueryElement * node = select_query.join();
|
||||
if (!node)
|
||||
return;
|
||||
|
||||
auto & table_join = const_cast<ASTTablesInSelectQueryElement *>(node)->table_join->as<ASTTableJoin &>();
|
||||
|
||||
if (table_join.strictness == ASTTableJoin::Strictness::Unspecified &&
|
||||
table_join.kind != ASTTableJoin::Kind::Cross)
|
||||
{
|
||||
if (join_default_strictness == JoinStrictness::ANY)
|
||||
table_join.strictness = ASTTableJoin::Strictness::Any;
|
||||
else if (join_default_strictness == JoinStrictness::ALL)
|
||||
table_join.strictness = ASTTableJoin::Strictness::All;
|
||||
else
|
||||
throw Exception("Expected ANY or ALL in JOIN section, because setting (join_default_strictness) is empty",
|
||||
DB::ErrorCodes::EXPECTED_ALL_OR_ANY);
|
||||
}
|
||||
|
||||
if (old_any && table_join.strictness == ASTTableJoin::Strictness::Any)
|
||||
table_join.strictness = ASTTableJoin::Strictness::RightAny;
|
||||
|
||||
out_table_join = table_join;
|
||||
}
|
||||
|
||||
/// Find the columns that are obtained by JOIN.
|
||||
void collectJoinedColumns(AnalyzedJoin & analyzed_join, const ASTSelectQuery & select_query,
|
||||
const std::vector<TableWithColumnNames> & tables, const Aliases & aliases)
|
||||
{
|
||||
const ASTTablesInSelectQueryElement * node = select_query.join();
|
||||
if (!node)
|
||||
return;
|
||||
|
||||
const auto & table_join = node->table_join->as<ASTTableJoin &>();
|
||||
|
||||
if (table_join.using_expression_list)
|
||||
{
|
||||
const auto & keys = table_join.using_expression_list->as<ASTExpressionList &>();
|
||||
for (const auto & key : keys.children)
|
||||
analyzed_join.addUsingKey(key);
|
||||
}
|
||||
else if (table_join.on_expression)
|
||||
{
|
||||
bool is_asof = (table_join.strictness == ASTTableJoin::Strictness::Asof);
|
||||
|
||||
CollectJoinOnKeysVisitor::Data data{analyzed_join, tables[0], tables[1], aliases, is_asof};
|
||||
CollectJoinOnKeysVisitor(data).visit(table_join.on_expression);
|
||||
if (!data.has_some)
|
||||
throw Exception("Cannot get JOIN keys from JOIN ON section: " + queryToString(table_join.on_expression),
|
||||
ErrorCodes::INVALID_JOIN_ON_EXPRESSION);
|
||||
if (is_asof)
|
||||
data.asofToJoinKeys();
|
||||
}
|
||||
}
|
||||
|
||||
void replaceJoinedTable(const ASTTablesInSelectQueryElement * join)
|
||||
{
|
||||
if (!join || !join->table_expression)
|
||||
return;
|
||||
|
||||
/// TODO: Push down for CROSS JOIN is not OK [disabled]
|
||||
const auto & table_join = join->table_join->as<ASTTableJoin &>();
|
||||
if (table_join.kind == ASTTableJoin::Kind::Cross)
|
||||
return;
|
||||
|
||||
auto & table_expr = join->table_expression->as<ASTTableExpression &>();
|
||||
if (table_expr.database_and_table_name)
|
||||
{
|
||||
const auto & table_id = table_expr.database_and_table_name->as<ASTIdentifier &>();
|
||||
String expr = "(select * from " + table_id.name + ") as " + table_id.shortName();
|
||||
|
||||
// FIXME: since the expression "a as b" exposes both "a" and "b" names, which is not equivalent to "(select * from a) as b",
|
||||
// we can't replace aliased tables.
|
||||
// FIXME: long table names include database name, which we can't save within alias.
|
||||
if (table_id.alias.empty() && table_id.isShort())
|
||||
{
|
||||
ParserTableExpression parser;
|
||||
table_expr = parseQuery(parser, expr, 0)->as<ASTTableExpression &>();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void checkJoin(const ASTTablesInSelectQueryElement * join)
|
||||
{
|
||||
if (!join->table_join)
|
||||
return;
|
||||
|
||||
const auto & table_join = join->table_join->as<ASTTableJoin &>();
|
||||
|
||||
if (table_join.strictness == ASTTableJoin::Strictness::Any)
|
||||
if (table_join.kind == ASTTableJoin::Kind::Full)
|
||||
throw Exception("ANY FULL JOINs are not implemented.", ErrorCodes::NOT_IMPLEMENTED);
|
||||
}
|
||||
|
||||
std::vector<const ASTFunction *> getAggregates(const ASTPtr & query)
|
||||
{
|
||||
if (const auto * select_query = query->as<ASTSelectQuery>())
|
||||
{
|
||||
/// There can not be aggregate functions inside the WHERE and PREWHERE.
|
||||
if (select_query->where())
|
||||
assertNoAggregates(select_query->where(), "in WHERE");
|
||||
if (select_query->prewhere())
|
||||
assertNoAggregates(select_query->prewhere(), "in PREWHERE");
|
||||
|
||||
GetAggregatesVisitor::Data data;
|
||||
GetAggregatesVisitor(data).visit(query);
|
||||
|
||||
/// There can not be other aggregate functions within the aggregate functions.
|
||||
for (const ASTFunction * node : data.aggregates)
|
||||
for (auto & arg : node->arguments->children)
|
||||
assertNoAggregates(arg, "inside another aggregate function");
|
||||
return data.aggregates;
|
||||
}
|
||||
else
|
||||
assertNoAggregates(query, "in wrong place");
|
||||
return {};
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
/// Calculate which columns are required to execute the expression.
|
||||
/// Then, delete all other columns from the list of available columns.
|
||||
/// After execution, columns will only contain the list of columns needed to read from the table.
|
||||
void SyntaxAnalyzerResult::collectUsedColumns(const ASTPtr & query, const NamesAndTypesList & additional_source_columns)
|
||||
{
|
||||
/// We caclulate required_source_columns with source_columns modifications and swap them on exit
|
||||
required_source_columns = source_columns;
|
||||
|
||||
if (!additional_source_columns.empty())
|
||||
{
|
||||
source_columns.insert(source_columns.end(), additional_source_columns.begin(), additional_source_columns.end());
|
||||
removeDuplicateColumns(source_columns);
|
||||
}
|
||||
|
||||
RequiredSourceColumnsVisitor::Data columns_context;
|
||||
RequiredSourceColumnsVisitor(columns_context).visit(query);
|
||||
|
||||
NameSet source_column_names;
|
||||
for (const auto & column : source_columns)
|
||||
source_column_names.insert(column.name);
|
||||
|
||||
NameSet required = columns_context.requiredColumns();
|
||||
|
||||
if (columns_context.has_table_join)
|
||||
{
|
||||
NameSet avaliable_columns;
|
||||
for (const auto & name : source_columns)
|
||||
avaliable_columns.insert(name.name);
|
||||
|
||||
/// Add columns obtained by JOIN (if needed).
|
||||
for (const auto & joined_column : analyzed_join->columnsFromJoinedTable())
|
||||
{
|
||||
auto & name = joined_column.name;
|
||||
if (avaliable_columns.count(name))
|
||||
continue;
|
||||
|
||||
if (required.count(name))
|
||||
{
|
||||
/// Optimisation: do not add columns needed only in JOIN ON section.
|
||||
if (columns_context.nameInclusion(name) > analyzed_join->rightKeyInclusion(name))
|
||||
analyzed_join->addJoinedColumn(joined_column);
|
||||
|
||||
required.erase(name);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
NameSet array_join_sources;
|
||||
if (columns_context.has_array_join)
|
||||
{
|
||||
/// Insert the columns required for the ARRAY JOIN calculation into the required columns list.
|
||||
for (const auto & result_source : array_join_result_to_source)
|
||||
array_join_sources.insert(result_source.second);
|
||||
|
||||
for (const auto & column_name_type : source_columns)
|
||||
if (array_join_sources.count(column_name_type.name))
|
||||
required.insert(column_name_type.name);
|
||||
}
|
||||
|
||||
const auto * select_query = query->as<ASTSelectQuery>();
|
||||
|
||||
/// You need to read at least one column to find the number of rows.
|
||||
if (select_query && required.empty())
|
||||
{
|
||||
maybe_optimize_trivial_count = true;
|
||||
/// We will find a column with minimum <compressed_size, type_size, uncompressed_size>.
|
||||
/// Because it is the column that is cheapest to read.
|
||||
struct ColumnSizeTuple
|
||||
{
|
||||
size_t compressed_size;
|
||||
size_t type_size;
|
||||
size_t uncompressed_size;
|
||||
String name;
|
||||
bool operator<(const ColumnSizeTuple & that) const
|
||||
{
|
||||
return std::tie(compressed_size, type_size, uncompressed_size)
|
||||
< std::tie(that.compressed_size, that.type_size, that.uncompressed_size);
|
||||
}
|
||||
};
|
||||
std::vector<ColumnSizeTuple> columns;
|
||||
if (storage)
|
||||
{
|
||||
auto column_sizes = storage->getColumnSizes();
|
||||
for (auto & source_column : source_columns)
|
||||
{
|
||||
auto c = column_sizes.find(source_column.name);
|
||||
if (c == column_sizes.end())
|
||||
continue;
|
||||
size_t type_size = source_column.type->haveMaximumSizeOfValue() ? source_column.type->getMaximumSizeOfValueInMemory() : 100;
|
||||
columns.emplace_back(ColumnSizeTuple{c->second.data_compressed, type_size, c->second.data_uncompressed, source_column.name});
|
||||
}
|
||||
}
|
||||
if (columns.size())
|
||||
required.insert(std::min_element(columns.begin(), columns.end())->name);
|
||||
else
|
||||
/// If we have no information about columns sizes, choose a column of minimum size of its data type.
|
||||
required.insert(ExpressionActions::getSmallestColumn(source_columns));
|
||||
}
|
||||
|
||||
NameSet unknown_required_source_columns = required;
|
||||
|
||||
for (NamesAndTypesList::iterator it = source_columns.begin(); it != source_columns.end();)
|
||||
{
|
||||
const String & column_name = it->name;
|
||||
unknown_required_source_columns.erase(column_name);
|
||||
|
||||
if (!required.count(column_name))
|
||||
source_columns.erase(it++);
|
||||
else
|
||||
++it;
|
||||
}
|
||||
|
||||
/// If there are virtual columns among the unknown columns. Remove them from the list of unknown and add
|
||||
/// in columns list, so that when further processing they are also considered.
|
||||
if (storage)
|
||||
{
|
||||
for (auto it = unknown_required_source_columns.begin(); it != unknown_required_source_columns.end();)
|
||||
{
|
||||
if (storage->hasColumn(*it))
|
||||
{
|
||||
source_columns.push_back(storage->getColumn(*it));
|
||||
unknown_required_source_columns.erase(it++);
|
||||
}
|
||||
else
|
||||
++it;
|
||||
}
|
||||
}
|
||||
|
||||
if (!unknown_required_source_columns.empty())
|
||||
{
|
||||
std::stringstream ss;
|
||||
ss << "Missing columns:";
|
||||
for (const auto & name : unknown_required_source_columns)
|
||||
ss << " '" << name << "'";
|
||||
ss << " while processing query: '" << queryToString(query) << "'";
|
||||
|
||||
ss << ", required columns:";
|
||||
for (const auto & name : columns_context.requiredColumns())
|
||||
ss << " '" << name << "'";
|
||||
|
||||
if (!source_column_names.empty())
|
||||
{
|
||||
ss << ", source columns:";
|
||||
for (const auto & name : source_column_names)
|
||||
ss << " '" << name << "'";
|
||||
}
|
||||
else
|
||||
ss << ", no source columns";
|
||||
|
||||
if (columns_context.has_table_join)
|
||||
{
|
||||
ss << ", joined columns:";
|
||||
for (const auto & column : analyzed_join->columnsFromJoinedTable())
|
||||
ss << " '" << column.name << "'";
|
||||
}
|
||||
|
||||
if (!array_join_sources.empty())
|
||||
{
|
||||
ss << ", arrayJoin columns:";
|
||||
for (const auto & name : array_join_sources)
|
||||
ss << " '" << name << "'";
|
||||
}
|
||||
|
||||
throw Exception(ss.str(), ErrorCodes::UNKNOWN_IDENTIFIER);
|
||||
}
|
||||
|
||||
required_source_columns.swap(source_columns);
|
||||
}
|
||||
|
||||
|
||||
SyntaxAnalyzerResultPtr SyntaxAnalyzer::analyze(
|
||||
ASTPtr & query,
|
||||
const NamesAndTypesList & source_columns_,
|
||||
const Names & required_result_columns,
|
||||
StoragePtr storage,
|
||||
const NamesAndTypesList & additional_source_columns) const
|
||||
{
|
||||
auto * select_query = query->as<ASTSelectQuery>();
|
||||
if (!storage && select_query)
|
||||
{
|
||||
if (auto db_and_table = getDatabaseAndTable(*select_query, 0))
|
||||
storage = context.tryGetTable(db_and_table->database, db_and_table->table);
|
||||
}
|
||||
|
||||
const auto & settings = context.getSettingsRef();
|
||||
|
||||
SyntaxAnalyzerResult result;
|
||||
result.storage = storage;
|
||||
result.source_columns = source_columns_;
|
||||
result.analyzed_join = std::make_shared<AnalyzedJoin>(settings, context.getTemporaryPath()); /// TODO: move to select_query logic
|
||||
|
||||
if (storage)
|
||||
collectSourceColumns(storage->getColumns(), result.source_columns, (select_query != nullptr));
|
||||
NameSet source_columns_set = removeDuplicateColumns(result.source_columns);
|
||||
std::vector<TableWithColumnNames> tables_with_columns;
|
||||
|
||||
if (select_query)
|
||||
{
|
||||
if (remove_duplicates)
|
||||
renameDuplicatedColumns(select_query);
|
||||
|
||||
const ASTTablesInSelectQueryElement * table_join_node = select_query->join();
|
||||
if (table_join_node)
|
||||
{
|
||||
if (!settings.any_join_distinct_right_table_keys)
|
||||
checkJoin(table_join_node);
|
||||
|
||||
if (settings.enable_optimize_predicate_expression)
|
||||
replaceJoinedTable(table_join_node);
|
||||
}
|
||||
|
||||
std::vector<const ASTTableExpression *> table_expressions = getTableExpressions(*select_query);
|
||||
tables_with_columns = getTablesWithColumns(table_expressions, context);
|
||||
|
||||
if (tables_with_columns.empty())
|
||||
{
|
||||
if (storage)
|
||||
{
|
||||
const ColumnsDescription & starage_columns = storage->getColumns();
|
||||
tables_with_columns.emplace_back(DatabaseAndTableWithAlias{}, starage_columns.getOrdinary().getNames());
|
||||
auto & table = tables_with_columns.back();
|
||||
table.addHiddenColumns(starage_columns.getMaterialized());
|
||||
table.addHiddenColumns(starage_columns.getAliases());
|
||||
table.addHiddenColumns(starage_columns.getVirtuals());
|
||||
}
|
||||
else
|
||||
{
|
||||
Names columns;
|
||||
columns.reserve(result.source_columns.size());
|
||||
for (const auto & column : result.source_columns)
|
||||
columns.push_back(column.name);
|
||||
tables_with_columns.emplace_back(DatabaseAndTableWithAlias{}, columns);
|
||||
}
|
||||
}
|
||||
|
||||
if (table_expressions.size() > 1)
|
||||
{
|
||||
result.analyzed_join->columns_from_joined_table = getColumnsFromTableExpression(*table_expressions[1], context);
|
||||
result.analyzed_join->deduplicateAndQualifyColumnNames(
|
||||
source_columns_set, tables_with_columns[1].table.getQualifiedNamePrefix());
|
||||
}
|
||||
|
||||
translateQualifiedNames(query, *select_query, source_columns_set, std::move(tables_with_columns));
|
||||
|
||||
/// Rewrite IN and/or JOIN for distributed tables according to distributed_product_mode setting.
|
||||
InJoinSubqueriesPreprocessor(context).visit(query);
|
||||
|
||||
/// Optimizes logical expressions.
|
||||
LogicalExpressionsOptimizer(select_query, settings.optimize_min_equality_disjunction_chain_length.value).perform();
|
||||
}
|
||||
|
||||
{
|
||||
CustomizeFunctionsVisitor::Data data{settings.count_distinct_implementation};
|
||||
CustomizeFunctionsVisitor(data).visit(query);
|
||||
}
|
||||
|
||||
/// Creates a dictionary `aliases`: alias -> ASTPtr
|
||||
{
|
||||
LogAST log;
|
||||
QueryAliasesVisitor::Data query_aliases_data{result.aliases};
|
||||
QueryAliasesVisitor(query_aliases_data, log.stream()).visit(query);
|
||||
}
|
||||
|
||||
/// Mark table ASTIdentifiers with not a column marker
|
||||
{
|
||||
MarkTableIdentifiersVisitor::Data data{result.aliases};
|
||||
MarkTableIdentifiersVisitor(data).visit(query);
|
||||
}
|
||||
|
||||
/// Common subexpression elimination. Rewrite rules.
|
||||
{
|
||||
QueryNormalizer::Data normalizer_data(result.aliases, context.getSettingsRef());
|
||||
QueryNormalizer(normalizer_data).visit(query);
|
||||
}
|
||||
|
||||
/// Remove unneeded columns according to 'required_result_columns'.
|
||||
/// Leave all selected columns in case of DISTINCT; columns that contain arrayJoin function inside.
|
||||
/// Must be after 'normalizeTree' (after expanding aliases, for aliases not get lost)
|
||||
/// and before 'executeScalarSubqueries', 'analyzeAggregation', etc. to avoid excessive calculations.
|
||||
if (select_query)
|
||||
removeUnneededColumnsFromSelectClause(select_query, required_result_columns, remove_duplicates);
|
||||
|
||||
/// Executing scalar subqueries - replacing them with constant values.
|
||||
executeScalarSubqueries(query, context, subquery_depth, result.scalars);
|
||||
|
||||
/// Optimize if with constant condition after constants was substituted instead of scalar subqueries.
|
||||
OptimizeIfWithConstantConditionVisitor(result.aliases).visit(query);
|
||||
|
||||
OptimizeIfChainsVisitor(result.aliases).visit(query);
|
||||
|
||||
if (select_query)
|
||||
{
|
||||
/// GROUP BY injective function elimination.
|
||||
optimizeGroupBy(select_query, source_columns_set, context);
|
||||
|
||||
/// Remove duplicate items from ORDER BY.
|
||||
optimizeOrderBy(select_query);
|
||||
|
||||
/// Remove duplicated elements from LIMIT BY clause.
|
||||
optimizeLimitBy(select_query);
|
||||
|
||||
/// Remove duplicated columns from USING(...).
|
||||
optimizeUsing(select_query);
|
||||
|
||||
/// array_join_alias_to_name, array_join_result_to_source.
|
||||
getArrayJoinedColumns(query, result, select_query, result.source_columns, source_columns_set);
|
||||
|
||||
/// Push the predicate expression down to the subqueries.
|
||||
result.rewrite_subqueries = PredicateExpressionsOptimizer(select_query, settings, context).optimize();
|
||||
|
||||
setJoinStrictness(*select_query, settings.join_default_strictness, settings.any_join_distinct_right_table_keys,
|
||||
result.analyzed_join->table_join);
|
||||
collectJoinedColumns(*result.analyzed_join, *select_query, tables_with_columns, result.aliases);
|
||||
}
|
||||
|
||||
result.aggregates = getAggregates(query);
|
||||
result.collectUsedColumns(query, additional_source_columns);
|
||||
return std::make_shared<const SyntaxAnalyzerResult>(result);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user