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39 lines
1.5 KiB
C++
39 lines
1.5 KiB
C++
#pragma once
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#include <TableFunctions/ITableFunction.h>
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namespace DB
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{
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/* merge (db_name, tables_regexp) - creates a temporary StorageMerge.
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* The structure of the table is taken from the first table that came up, suitable for regexp.
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* If there is no such table, an exception is thrown.
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*/
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class TableFunctionMerge : public ITableFunction
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{
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public:
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static constexpr auto name = "merge";
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std::string getName() const override { return name; }
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private:
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StoragePtr executeImpl(const ASTPtr & ast_function, ContextPtr context, const std::string & table_name, ColumnsDescription cached_columns) const override;
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const char * getStorageTypeName() const override { return "Merge"; }
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using TableSet = std::set<String>;
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using DBToTableSetMap = std::map<String, TableSet>;
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const DBToTableSetMap & getSourceDatabasesAndTables(ContextPtr context) const;
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ColumnsDescription getActualTableStructure(ContextPtr context) const override;
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std::vector<size_t> skipAnalysisForArguments(const QueryTreeNodePtr & query_node_table_function, ContextPtr context) const override;
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void parseArguments(const ASTPtr & ast_function, ContextPtr context) override;
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static TableSet getMatchedTablesWithAccess(const String & database_name, const String & table_regexp, const ContextPtr & context);
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String source_database_name_or_regexp;
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String source_table_regexp;
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bool database_is_regexp = false;
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mutable std::optional<DBToTableSetMap> source_databases_and_tables;
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};
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}
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