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879 lines
35 KiB
C++
879 lines
35 KiB
C++
#include <QueryPipeline/narrowPipe.h>
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#include <Processors/Sources/SourceFromSingleChunk.h>
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#include <Storages/StorageMerge.h>
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#include <Storages/StorageFactory.h>
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#include <Storages/VirtualColumnUtils.h>
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#include <Storages/AlterCommands.h>
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#include <Interpreters/Context.h>
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#include <Interpreters/TreeRewriter.h>
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#include <Interpreters/ExpressionActions.h>
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#include <Interpreters/evaluateConstantExpression.h>
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#include <Interpreters/InterpreterSelectQuery.h>
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#include <Interpreters/IdentifierSemantic.h>
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#include <Interpreters/getHeaderForProcessingStage.h>
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#include <Interpreters/addTypeConversionToAST.h>
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#include <Interpreters/replaceAliasColumnsInQuery.h>
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#include <Parsers/ASTFunction.h>
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#include <Parsers/ASTSelectQuery.h>
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#include <Parsers/ASTLiteral.h>
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#include <Parsers/ASTIdentifier.h>
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#include <Parsers/ASTExpressionList.h>
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#include <DataTypes/DataTypeString.h>
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#include <Columns/ColumnString.h>
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#include <Common/typeid_cast.h>
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#include <Common/checkStackSize.h>
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#include <Databases/IDatabase.h>
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#include <base/range.h>
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#include <algorithm>
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#include <Parsers/queryToString.h>
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#include <Processors/Transforms/MaterializingTransform.h>
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#include <Processors/ConcatProcessor.h>
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#include <Processors/Transforms/ExpressionTransform.h>
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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 BAD_ARGUMENTS;
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extern const int LOGICAL_ERROR;
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extern const int NOT_IMPLEMENTED;
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extern const int ILLEGAL_PREWHERE;
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extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
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extern const int SAMPLING_NOT_SUPPORTED;
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extern const int ALTER_OF_COLUMN_IS_FORBIDDEN;
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extern const int CANNOT_EXTRACT_TABLE_STRUCTURE;
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}
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StorageMerge::StorageMerge(
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const StorageID & table_id_,
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const ColumnsDescription & columns_,
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const String & comment,
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const String & source_database_name_or_regexp_,
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bool database_is_regexp_,
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const DBToTableSetMap & source_databases_and_tables_,
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ContextPtr context_)
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: IStorage(table_id_)
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, WithContext(context_->getGlobalContext())
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, source_database_regexp(source_database_name_or_regexp_)
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, source_databases_and_tables(source_databases_and_tables_)
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, source_database_name_or_regexp(source_database_name_or_regexp_)
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, database_is_regexp(database_is_regexp_)
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{
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StorageInMemoryMetadata storage_metadata;
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storage_metadata.setColumns(columns_.empty() ? getColumnsDescriptionFromSourceTables() : columns_);
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storage_metadata.setComment(comment);
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setInMemoryMetadata(storage_metadata);
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}
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StorageMerge::StorageMerge(
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const StorageID & table_id_,
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const ColumnsDescription & columns_,
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const String & comment,
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const String & source_database_name_or_regexp_,
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bool database_is_regexp_,
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const String & source_table_regexp_,
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ContextPtr context_)
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: IStorage(table_id_)
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, WithContext(context_->getGlobalContext())
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, source_database_regexp(source_database_name_or_regexp_)
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, source_table_regexp(source_table_regexp_)
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, source_database_name_or_regexp(source_database_name_or_regexp_)
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, database_is_regexp(database_is_regexp_)
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{
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StorageInMemoryMetadata storage_metadata;
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storage_metadata.setColumns(columns_.empty() ? getColumnsDescriptionFromSourceTables() : columns_);
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storage_metadata.setComment(comment);
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setInMemoryMetadata(storage_metadata);
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}
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ColumnsDescription StorageMerge::getColumnsDescriptionFromSourceTables() const
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{
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auto table = getFirstTable([](auto && t) { return t; });
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if (!table)
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throw Exception{ErrorCodes::CANNOT_EXTRACT_TABLE_STRUCTURE, "There are no tables satisfied provided regexp, you must specify table structure manually"};
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return table->getInMemoryMetadataPtr()->getColumns();
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}
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template <typename F>
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StoragePtr StorageMerge::getFirstTable(F && predicate) const
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{
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auto database_table_iterators = getDatabaseIterators(getContext());
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for (auto & iterator : database_table_iterators)
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{
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while (iterator->isValid())
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{
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const auto & table = iterator->table();
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if (table.get() != this && predicate(table))
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return table;
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iterator->next();
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}
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}
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return {};
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}
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template <typename F>
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void StorageMerge::forEachTable(F && func) const
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{
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getFirstTable([&func](const auto & table)
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{
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func(table);
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return false;
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});
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}
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bool StorageMerge::isRemote() const
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{
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auto first_remote_table = getFirstTable([](const StoragePtr & table) { return table && table->isRemote(); });
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return first_remote_table != nullptr;
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}
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bool StorageMerge::canMoveConditionsToPrewhere() const
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{
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/// NOTE: This check is used during query analysis as condition for applying
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/// "move to PREWHERE" optimization. However, it contains a logical race:
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/// If new table that matches regexp for current storage and doesn't support PREWHERE
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/// will appear after this check and before calling "read" method, the optimized query may fail.
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/// Since it's quite rare case, we just ignore this possibility.
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return getFirstTable([](const auto & table) { return !table->canMoveConditionsToPrewhere(); }) == nullptr;
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}
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bool StorageMerge::mayBenefitFromIndexForIn(const ASTPtr & left_in_operand, ContextPtr query_context, const StorageMetadataPtr & /*metadata_snapshot*/) const
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{
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/// It's beneficial if it is true for at least one table.
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StorageListWithLocks selected_tables = getSelectedTables(query_context);
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size_t i = 0;
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for (const auto & table : selected_tables)
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{
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const auto & storage_ptr = std::get<1>(table);
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auto metadata_snapshot = storage_ptr->getInMemoryMetadataPtr();
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if (storage_ptr->mayBenefitFromIndexForIn(left_in_operand, query_context, metadata_snapshot))
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return true;
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++i;
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/// For simplicity reasons, check only first ten tables.
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if (i > 10)
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break;
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}
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return false;
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}
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QueryProcessingStage::Enum StorageMerge::getQueryProcessingStage(
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ContextPtr local_context,
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QueryProcessingStage::Enum to_stage,
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const StorageSnapshotPtr &,
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SelectQueryInfo & query_info) const
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{
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/// In case of JOIN the first stage (which includes JOIN)
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/// should be done on the initiator always.
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///
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/// Since in case of JOIN query on shards will receive query without JOIN (and their columns).
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/// (see removeJoin())
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///
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/// And for this we need to return FetchColumns.
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if (const auto * select = query_info.query->as<ASTSelectQuery>(); select && hasJoin(*select))
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return QueryProcessingStage::FetchColumns;
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auto stage_in_source_tables = QueryProcessingStage::FetchColumns;
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DatabaseTablesIterators database_table_iterators = getDatabaseIterators(local_context);
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size_t selected_table_size = 0;
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/// TODO: Find a way to support projections for StorageMerge
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query_info.ignore_projections = true;
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for (const auto & iterator : database_table_iterators)
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{
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while (iterator->isValid())
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{
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const auto & table = iterator->table();
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if (table && table.get() != this)
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{
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++selected_table_size;
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stage_in_source_tables = std::max(
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stage_in_source_tables,
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table->getQueryProcessingStage(local_context, to_stage,
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table->getStorageSnapshot(table->getInMemoryMetadataPtr(), local_context), query_info));
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}
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iterator->next();
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}
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}
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return selected_table_size == 1 ? stage_in_source_tables : std::min(stage_in_source_tables, QueryProcessingStage::WithMergeableState);
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}
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SelectQueryInfo StorageMerge::getModifiedQueryInfo(
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const SelectQueryInfo & query_info, ContextPtr modified_context, const StorageID & current_storage_id, bool is_merge_engine)
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{
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SelectQueryInfo modified_query_info = query_info;
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modified_query_info.query = query_info.query->clone();
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/// Original query could contain JOIN but we need only the first joined table and its columns.
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auto & modified_select = modified_query_info.query->as<ASTSelectQuery &>();
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TreeRewriterResult new_analyzer_res = *modified_query_info.syntax_analyzer_result;
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removeJoin(modified_select, new_analyzer_res, modified_context);
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modified_query_info.syntax_analyzer_result = std::make_shared<TreeRewriterResult>(std::move(new_analyzer_res));
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if (!is_merge_engine)
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{
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VirtualColumnUtils::rewriteEntityInAst(modified_query_info.query, "_table", current_storage_id.table_name);
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VirtualColumnUtils::rewriteEntityInAst(modified_query_info.query, "_database", current_storage_id.database_name);
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}
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return modified_query_info;
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}
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Pipe StorageMerge::read(
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const Names & column_names,
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const StorageSnapshotPtr & storage_snapshot,
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SelectQueryInfo & query_info,
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ContextPtr local_context,
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QueryProcessingStage::Enum processed_stage,
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const size_t max_block_size,
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unsigned num_streams)
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{
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Pipes pipes;
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bool has_database_virtual_column = false;
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bool has_table_virtual_column = false;
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Names real_column_names;
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real_column_names.reserve(column_names.size());
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for (const auto & column_name : column_names)
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{
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if (column_name == "_database" && isVirtualColumn(column_name, storage_snapshot->metadata))
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has_database_virtual_column = true;
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else if (column_name == "_table" && isVirtualColumn(column_name, storage_snapshot->metadata))
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has_table_virtual_column = true;
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else
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real_column_names.push_back(column_name);
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}
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/** Just in case, turn off optimization "transfer to PREWHERE",
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* since there is no certainty that it works when one of table is MergeTree and other is not.
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*/
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auto modified_context = Context::createCopy(local_context);
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modified_context->setSetting("optimize_move_to_prewhere", false);
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/// What will be result structure depending on query processed stage in source tables?
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Block header = getHeaderForProcessingStage(column_names, storage_snapshot, query_info, local_context, processed_stage);
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/** First we make list of selected tables to find out its size.
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* This is necessary to correctly pass the recommended number of threads to each table.
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*/
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StorageListWithLocks selected_tables
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= getSelectedTables(local_context, query_info.query, has_database_virtual_column, has_table_virtual_column);
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if (selected_tables.empty())
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{
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auto modified_query_info = getModifiedQueryInfo(query_info, modified_context, getStorageID(), false);
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/// FIXME: do we support sampling in this case?
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return createSources(
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{},
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modified_query_info,
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processed_stage,
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max_block_size,
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header,
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{},
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{},
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real_column_names,
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modified_context,
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0,
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has_database_virtual_column,
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has_table_virtual_column);
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}
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size_t tables_count = selected_tables.size();
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Float64 num_streams_multiplier
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= std::min(static_cast<unsigned>(tables_count), std::max(1U, static_cast<unsigned>(local_context->getSettingsRef().max_streams_multiplier_for_merge_tables)));
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num_streams *= num_streams_multiplier;
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size_t remaining_streams = num_streams;
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InputOrderInfoPtr input_sorting_info;
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if (query_info.order_optimizer)
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{
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for (auto it = selected_tables.begin(); it != selected_tables.end(); ++it)
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{
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auto storage_ptr = std::get<1>(*it);
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auto storage_metadata_snapshot = storage_ptr->getInMemoryMetadataPtr();
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auto current_info = query_info.order_optimizer->getInputOrder(storage_metadata_snapshot, local_context);
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if (it == selected_tables.begin())
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input_sorting_info = current_info;
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else if (!current_info || (input_sorting_info && *current_info != *input_sorting_info))
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input_sorting_info.reset();
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if (!input_sorting_info)
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break;
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}
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query_info.input_order_info = input_sorting_info;
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}
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auto sample_block = getInMemoryMetadataPtr()->getSampleBlock();
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for (const auto & table : selected_tables)
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{
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size_t current_need_streams = tables_count >= num_streams ? 1 : (num_streams / tables_count);
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size_t current_streams = std::min(current_need_streams, remaining_streams);
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remaining_streams -= current_streams;
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current_streams = std::max(static_cast<size_t>(1), current_streams);
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const auto & storage = std::get<1>(table);
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/// If sampling requested, then check that table supports it.
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if (query_info.query->as<ASTSelectQuery>()->sampleSize() && !storage->supportsSampling())
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throw Exception("Illegal SAMPLE: table doesn't support sampling", ErrorCodes::SAMPLING_NOT_SUPPORTED);
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Aliases aliases;
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auto storage_metadata_snapshot = storage->getInMemoryMetadataPtr();
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auto storage_columns = storage_metadata_snapshot->getColumns();
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auto nested_storage_snaphsot = storage->getStorageSnapshot(storage_metadata_snapshot, local_context);
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auto modified_query_info = getModifiedQueryInfo(query_info, modified_context, storage->getStorageID(), storage->as<StorageMerge>());
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auto syntax_result = TreeRewriter(local_context).analyzeSelect(
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modified_query_info.query, TreeRewriterResult({}, storage, nested_storage_snaphsot));
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Names column_names_as_aliases;
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bool with_aliases = processed_stage == QueryProcessingStage::FetchColumns && !storage_columns.getAliases().empty();
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if (with_aliases)
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{
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ASTPtr required_columns_expr_list = std::make_shared<ASTExpressionList>();
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ASTPtr column_expr;
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for (const auto & column : real_column_names)
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{
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const auto column_default = storage_columns.getDefault(column);
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bool is_alias = column_default && column_default->kind == ColumnDefaultKind::Alias;
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if (is_alias)
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{
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column_expr = column_default->expression->clone();
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replaceAliasColumnsInQuery(column_expr, storage_metadata_snapshot->getColumns(),
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syntax_result->array_join_result_to_source, local_context);
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auto column_description = storage_columns.get(column);
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column_expr = addTypeConversionToAST(std::move(column_expr), column_description.type->getName(),
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storage_metadata_snapshot->getColumns().getAll(), local_context);
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column_expr = setAlias(column_expr, column);
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auto type = sample_block.getByName(column).type;
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aliases.push_back({ .name = column, .type = type, .expression = column_expr->clone() });
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}
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else
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column_expr = std::make_shared<ASTIdentifier>(column);
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required_columns_expr_list->children.emplace_back(std::move(column_expr));
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}
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syntax_result = TreeRewriter(local_context).analyze(
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required_columns_expr_list, storage_columns.getAllPhysical(), storage, storage->getStorageSnapshot(storage_metadata_snapshot, local_context));
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auto alias_actions = ExpressionAnalyzer(required_columns_expr_list, syntax_result, local_context).getActionsDAG(true);
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column_names_as_aliases = alias_actions->getRequiredColumns().getNames();
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if (column_names_as_aliases.empty())
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column_names_as_aliases.push_back(ExpressionActions::getSmallestColumn(storage_metadata_snapshot->getColumns().getAllPhysical()));
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}
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auto source_pipe = createSources(
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nested_storage_snaphsot,
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modified_query_info,
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processed_stage,
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max_block_size,
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header,
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aliases,
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table,
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column_names_as_aliases.empty() ? real_column_names : column_names_as_aliases,
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modified_context,
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current_streams,
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has_database_virtual_column,
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has_table_virtual_column);
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pipes.emplace_back(std::move(source_pipe));
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}
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auto pipe = Pipe::unitePipes(std::move(pipes));
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if (!pipe.empty() && !query_info.input_order_info)
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// It's possible to have many tables read from merge, resize(num_streams) might open too many files at the same time.
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// Using narrowPipe instead. But in case of reading in order of primary key, we cannot do it,
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// because narrowPipe doesn't preserve order.
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narrowPipe(pipe, num_streams);
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return pipe;
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}
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Pipe StorageMerge::createSources(
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const StorageSnapshotPtr & storage_snapshot,
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SelectQueryInfo & modified_query_info,
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const QueryProcessingStage::Enum & processed_stage,
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const UInt64 max_block_size,
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const Block & header,
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const Aliases & aliases,
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const StorageWithLockAndName & storage_with_lock,
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Names & real_column_names,
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ContextMutablePtr modified_context,
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size_t streams_num,
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bool has_database_virtual_column,
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bool has_table_virtual_column,
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bool concat_streams)
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{
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const auto & [database_name, storage, struct_lock, table_name] = storage_with_lock;
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auto & modified_select = modified_query_info.query->as<ASTSelectQuery &>();
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Pipe pipe;
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if (!storage)
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{
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pipe = QueryPipelineBuilder::getPipe(InterpreterSelectQuery(
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modified_query_info.query, modified_context,
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Pipe(std::make_shared<SourceFromSingleChunk>(header)),
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SelectQueryOptions(processed_stage).analyze()).buildQueryPipeline());
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pipe.addInterpreterContext(modified_context);
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return pipe;
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}
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if (!modified_select.final() && storage->needRewriteQueryWithFinal(real_column_names))
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{
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/// NOTE: It may not work correctly in some cases, because query was analyzed without final.
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/// However, it's needed for MaterializedMySQL and it's unlikely that someone will use it with Merge tables.
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modified_select.setFinal();
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}
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auto storage_stage
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= storage->getQueryProcessingStage(modified_context, QueryProcessingStage::Complete, storage_snapshot, modified_query_info);
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if (processed_stage <= storage_stage)
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{
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/// If there are only virtual columns in query, you must request at least one other column.
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if (real_column_names.empty())
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real_column_names.push_back(ExpressionActions::getSmallestColumn(storage_snapshot->metadata->getColumns().getAllPhysical()));
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pipe = storage->read(
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real_column_names,
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storage_snapshot,
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modified_query_info,
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modified_context,
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processed_stage,
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max_block_size,
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UInt32(streams_num));
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}
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else if (processed_stage > storage_stage)
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{
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modified_select.replaceDatabaseAndTable(database_name, table_name);
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/// Maximum permissible parallelism is streams_num
|
|
modified_context->setSetting("max_threads", streams_num);
|
|
modified_context->setSetting("max_streams_to_max_threads_ratio", 1);
|
|
|
|
/// TODO: Find a way to support projections for StorageMerge
|
|
InterpreterSelectQuery interpreter{
|
|
modified_query_info.query, modified_context, SelectQueryOptions(processed_stage).ignoreProjections()};
|
|
|
|
|
|
pipe = QueryPipelineBuilder::getPipe(interpreter.buildQueryPipeline());
|
|
|
|
/** Materialization is needed, since from distributed storage the constants come materialized.
|
|
* If you do not do this, different types (Const and non-Const) columns will be produced in different threads,
|
|
* And this is not allowed, since all code is based on the assumption that in the block stream all types are the same.
|
|
*/
|
|
pipe.addSimpleTransform([](const Block & stream_header) { return std::make_shared<MaterializingTransform>(stream_header); });
|
|
}
|
|
|
|
if (!pipe.empty())
|
|
{
|
|
if (concat_streams && pipe.numOutputPorts() > 1)
|
|
{
|
|
// It's possible to have many tables read from merge, resize(1) might open too many files at the same time.
|
|
// Using concat instead.
|
|
pipe.addTransform(std::make_shared<ConcatProcessor>(pipe.getHeader(), pipe.numOutputPorts()));
|
|
}
|
|
|
|
/// Add virtual columns if we don't already have them.
|
|
|
|
Block pipe_header = pipe.getHeader();
|
|
|
|
if (has_database_virtual_column && !pipe_header.has("_database"))
|
|
{
|
|
ColumnWithTypeAndName column;
|
|
column.name = "_database";
|
|
column.type = std::make_shared<DataTypeString>();
|
|
column.column = column.type->createColumnConst(0, Field(database_name));
|
|
|
|
auto adding_column_dag = ActionsDAG::makeAddingColumnActions(std::move(column));
|
|
auto adding_column_actions = std::make_shared<ExpressionActions>(
|
|
std::move(adding_column_dag),
|
|
ExpressionActionsSettings::fromContext(modified_context, CompileExpressions::yes));
|
|
|
|
pipe.addSimpleTransform([&](const Block & stream_header)
|
|
{
|
|
return std::make_shared<ExpressionTransform>(stream_header, adding_column_actions);
|
|
});
|
|
}
|
|
|
|
if (has_table_virtual_column && !pipe_header.has("_table"))
|
|
{
|
|
ColumnWithTypeAndName column;
|
|
column.name = "_table";
|
|
column.type = std::make_shared<DataTypeString>();
|
|
column.column = column.type->createColumnConst(0, Field(table_name));
|
|
|
|
auto adding_column_dag = ActionsDAG::makeAddingColumnActions(std::move(column));
|
|
auto adding_column_actions = std::make_shared<ExpressionActions>(
|
|
std::move(adding_column_dag),
|
|
ExpressionActionsSettings::fromContext(modified_context, CompileExpressions::yes));
|
|
|
|
pipe.addSimpleTransform([&](const Block & stream_header)
|
|
{
|
|
return std::make_shared<ExpressionTransform>(stream_header, adding_column_actions);
|
|
});
|
|
}
|
|
|
|
/// Subordinary tables could have different but convertible types, like numeric types of different width.
|
|
/// We must return streams with structure equals to structure of Merge table.
|
|
convertingSourceStream(header, storage_snapshot->metadata, aliases, modified_context, modified_query_info.query, pipe, processed_stage);
|
|
|
|
pipe.addTableLock(struct_lock);
|
|
pipe.addStorageHolder(storage);
|
|
pipe.addInterpreterContext(modified_context);
|
|
}
|
|
|
|
return pipe;
|
|
}
|
|
|
|
StorageMerge::StorageListWithLocks StorageMerge::getSelectedTables(
|
|
ContextPtr query_context,
|
|
const ASTPtr & query /* = nullptr */,
|
|
bool filter_by_database_virtual_column /* = false */,
|
|
bool filter_by_table_virtual_column /* = false */) const
|
|
{
|
|
assert(!filter_by_database_virtual_column || !filter_by_table_virtual_column || query);
|
|
|
|
const Settings & settings = query_context->getSettingsRef();
|
|
StorageListWithLocks selected_tables;
|
|
DatabaseTablesIterators database_table_iterators = getDatabaseIterators(getContext());
|
|
|
|
MutableColumnPtr database_name_virtual_column;
|
|
MutableColumnPtr table_name_virtual_column;
|
|
if (filter_by_database_virtual_column)
|
|
{
|
|
database_name_virtual_column = ColumnString::create();
|
|
}
|
|
|
|
if (filter_by_table_virtual_column)
|
|
{
|
|
table_name_virtual_column = ColumnString::create();
|
|
}
|
|
|
|
for (const auto & iterator : database_table_iterators)
|
|
{
|
|
if (filter_by_database_virtual_column)
|
|
database_name_virtual_column->insert(iterator->databaseName());
|
|
while (iterator->isValid())
|
|
{
|
|
StoragePtr storage = iterator->table();
|
|
if (!storage)
|
|
continue;
|
|
|
|
if (query && query->as<ASTSelectQuery>()->prewhere() && !storage->supportsPrewhere())
|
|
throw Exception("Storage " + storage->getName() + " doesn't support PREWHERE.", ErrorCodes::ILLEGAL_PREWHERE);
|
|
|
|
if (storage.get() != this)
|
|
{
|
|
auto table_lock = storage->lockForShare(query_context->getCurrentQueryId(), settings.lock_acquire_timeout);
|
|
selected_tables.emplace_back(iterator->databaseName(), storage, std::move(table_lock), iterator->name());
|
|
if (filter_by_table_virtual_column)
|
|
table_name_virtual_column->insert(iterator->name());
|
|
}
|
|
|
|
iterator->next();
|
|
}
|
|
}
|
|
|
|
if (filter_by_database_virtual_column)
|
|
{
|
|
/// Filter names of selected tables if there is a condition on "_database" virtual column in WHERE clause
|
|
Block virtual_columns_block
|
|
= Block{ColumnWithTypeAndName(std::move(database_name_virtual_column), std::make_shared<DataTypeString>(), "_database")};
|
|
VirtualColumnUtils::filterBlockWithQuery(query, virtual_columns_block, query_context);
|
|
auto values = VirtualColumnUtils::extractSingleValueFromBlock<String>(virtual_columns_block, "_database");
|
|
|
|
/// Remove unused databases from the list
|
|
selected_tables.remove_if([&](const auto & elem) { return values.find(std::get<0>(elem)) == values.end(); });
|
|
}
|
|
|
|
if (filter_by_table_virtual_column)
|
|
{
|
|
/// Filter names of selected tables if there is a condition on "_table" virtual column in WHERE clause
|
|
Block virtual_columns_block = Block{ColumnWithTypeAndName(std::move(table_name_virtual_column), std::make_shared<DataTypeString>(), "_table")};
|
|
VirtualColumnUtils::filterBlockWithQuery(query, virtual_columns_block, query_context);
|
|
auto values = VirtualColumnUtils::extractSingleValueFromBlock<String>(virtual_columns_block, "_table");
|
|
|
|
/// Remove unused tables from the list
|
|
selected_tables.remove_if([&](const auto & elem) { return values.find(std::get<3>(elem)) == values.end(); });
|
|
}
|
|
|
|
return selected_tables;
|
|
}
|
|
|
|
DatabaseTablesIteratorPtr StorageMerge::getDatabaseIterator(const String & database_name, ContextPtr local_context) const
|
|
{
|
|
auto database = DatabaseCatalog::instance().getDatabase(database_name);
|
|
|
|
auto table_name_match = [this, database_name](const String & table_name_) -> bool
|
|
{
|
|
if (source_databases_and_tables)
|
|
{
|
|
if (auto it = source_databases_and_tables->find(database_name); it != source_databases_and_tables->end())
|
|
return it->second.contains(table_name_);
|
|
else
|
|
return false;
|
|
}
|
|
else
|
|
return source_table_regexp->match(table_name_);
|
|
};
|
|
|
|
return database->getTablesIterator(local_context, table_name_match);
|
|
}
|
|
|
|
StorageMerge::DatabaseTablesIterators StorageMerge::getDatabaseIterators(ContextPtr local_context) const
|
|
{
|
|
try
|
|
{
|
|
checkStackSize();
|
|
}
|
|
catch (Exception & e)
|
|
{
|
|
e.addMessage("while getting table iterator of Merge table. Maybe caused by two Merge tables that will endlessly try to read each other's data");
|
|
throw;
|
|
}
|
|
|
|
DatabaseTablesIterators database_table_iterators;
|
|
|
|
/// database_name argument is not a regexp
|
|
if (!database_is_regexp)
|
|
database_table_iterators.emplace_back(getDatabaseIterator(source_database_name_or_regexp, local_context));
|
|
|
|
/// database_name argument is a regexp
|
|
else
|
|
{
|
|
auto databases = DatabaseCatalog::instance().getDatabases();
|
|
|
|
for (const auto & db : databases)
|
|
{
|
|
if (source_database_regexp->match(db.first))
|
|
database_table_iterators.emplace_back(getDatabaseIterator(db.first, local_context));
|
|
}
|
|
}
|
|
|
|
return database_table_iterators;
|
|
}
|
|
|
|
|
|
void StorageMerge::checkAlterIsPossible(const AlterCommands & commands, ContextPtr local_context) const
|
|
{
|
|
auto name_deps = getDependentViewsByColumn(local_context);
|
|
for (const auto & command : commands)
|
|
{
|
|
if (command.type != AlterCommand::Type::ADD_COLUMN && command.type != AlterCommand::Type::MODIFY_COLUMN
|
|
&& command.type != AlterCommand::Type::DROP_COLUMN && command.type != AlterCommand::Type::COMMENT_COLUMN
|
|
&& command.type != AlterCommand::Type::COMMENT_TABLE)
|
|
throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Alter of type '{}' is not supported by storage {}",
|
|
command.type, getName());
|
|
|
|
if (command.type == AlterCommand::Type::DROP_COLUMN && !command.clear)
|
|
{
|
|
const auto & deps_mv = name_deps[command.column_name];
|
|
if (!deps_mv.empty())
|
|
{
|
|
throw Exception(
|
|
"Trying to ALTER DROP column " + backQuoteIfNeed(command.column_name) + " which is referenced by materialized view "
|
|
+ toString(deps_mv),
|
|
ErrorCodes::ALTER_OF_COLUMN_IS_FORBIDDEN);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void StorageMerge::alter(
|
|
const AlterCommands & params, ContextPtr local_context, AlterLockHolder &)
|
|
{
|
|
auto table_id = getStorageID();
|
|
|
|
StorageInMemoryMetadata storage_metadata = getInMemoryMetadata();
|
|
params.apply(storage_metadata, local_context);
|
|
DatabaseCatalog::instance().getDatabase(table_id.database_name)->alterTable(local_context, table_id, storage_metadata);
|
|
setInMemoryMetadata(storage_metadata);
|
|
}
|
|
|
|
void StorageMerge::convertingSourceStream(
|
|
const Block & header,
|
|
const StorageMetadataPtr & metadata_snapshot,
|
|
const Aliases & aliases,
|
|
ContextPtr local_context,
|
|
ASTPtr & query,
|
|
Pipe & pipe,
|
|
QueryProcessingStage::Enum processed_stage)
|
|
{
|
|
Block before_block_header = pipe.getHeader();
|
|
|
|
auto storage_sample_block = metadata_snapshot->getSampleBlock();
|
|
auto pipe_columns = pipe.getHeader().getNamesAndTypesList();
|
|
|
|
for (const auto & alias : aliases)
|
|
{
|
|
pipe_columns.emplace_back(NameAndTypePair(alias.name, alias.type));
|
|
ASTPtr expr = alias.expression;
|
|
auto syntax_result = TreeRewriter(local_context).analyze(expr, pipe_columns);
|
|
auto expression_analyzer = ExpressionAnalyzer{alias.expression, syntax_result, local_context};
|
|
|
|
auto dag = std::make_shared<ActionsDAG>(pipe_columns);
|
|
auto actions_dag = expression_analyzer.getActionsDAG(true, false);
|
|
auto actions = std::make_shared<ExpressionActions>(actions_dag, ExpressionActionsSettings::fromContext(local_context, CompileExpressions::yes));
|
|
|
|
pipe.addSimpleTransform([&](const Block & stream_header)
|
|
{
|
|
return std::make_shared<ExpressionTransform>(stream_header, actions);
|
|
});
|
|
}
|
|
|
|
{
|
|
auto convert_actions_dag = ActionsDAG::makeConvertingActions(pipe.getHeader().getColumnsWithTypeAndName(),
|
|
header.getColumnsWithTypeAndName(),
|
|
ActionsDAG::MatchColumnsMode::Name);
|
|
auto actions = std::make_shared<ExpressionActions>(
|
|
convert_actions_dag,
|
|
ExpressionActionsSettings::fromContext(local_context, CompileExpressions::yes));
|
|
|
|
pipe.addSimpleTransform([&](const Block & stream_header)
|
|
{
|
|
return std::make_shared<ExpressionTransform>(stream_header, actions);
|
|
});
|
|
}
|
|
|
|
auto where_expression = query->as<ASTSelectQuery>()->where();
|
|
|
|
if (!where_expression)
|
|
return;
|
|
|
|
if (processed_stage > QueryProcessingStage::FetchColumns)
|
|
{
|
|
for (size_t column_index : collections::range(0, header.columns()))
|
|
{
|
|
ColumnWithTypeAndName header_column = header.getByPosition(column_index);
|
|
ColumnWithTypeAndName before_column = before_block_header.getByName(header_column.name);
|
|
/// If the processed_stage greater than FetchColumns and the block structure between streams is different.
|
|
/// the where expression maybe invalid because of ConvertingTransform.
|
|
/// So we need to throw exception.
|
|
if (!header_column.type->equals(*before_column.type.get()))
|
|
{
|
|
NamesAndTypesList source_columns = metadata_snapshot->getSampleBlock().getNamesAndTypesList();
|
|
auto virtual_column = *getVirtuals().tryGetByName("_table");
|
|
source_columns.emplace_back(NameAndTypePair{virtual_column.name, virtual_column.type});
|
|
auto syntax_result = TreeRewriter(local_context).analyze(where_expression, source_columns);
|
|
ExpressionActionsPtr actions = ExpressionAnalyzer{where_expression, syntax_result, local_context}.getActions(false, false);
|
|
Names required_columns = actions->getRequiredColumns();
|
|
|
|
for (const auto & required_column : required_columns)
|
|
{
|
|
if (required_column == header_column.name)
|
|
throw Exception("Block structure mismatch in Merge Storage: different types:\n" + before_block_header.dumpStructure()
|
|
+ "\n" + header.dumpStructure(), ErrorCodes::LOGICAL_ERROR);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
IStorage::ColumnSizeByName StorageMerge::getColumnSizes() const
|
|
{
|
|
ColumnSizeByName column_sizes;
|
|
|
|
forEachTable([&](const auto & table)
|
|
{
|
|
for (const auto & [name, size] : table->getColumnSizes())
|
|
column_sizes[name].add(size);
|
|
});
|
|
|
|
return column_sizes;
|
|
}
|
|
|
|
|
|
std::tuple<bool /* is_regexp */, ASTPtr> StorageMerge::evaluateDatabaseName(const ASTPtr & node, ContextPtr context_)
|
|
{
|
|
if (const auto * func = node->as<ASTFunction>(); func && func->name == "REGEXP")
|
|
{
|
|
if (func->arguments->children.size() != 1)
|
|
throw Exception("REGEXP in Merge ENGINE takes only one argument", ErrorCodes::BAD_ARGUMENTS);
|
|
|
|
auto * literal = func->arguments->children[0]->as<ASTLiteral>();
|
|
if (!literal || literal->value.safeGet<String>().empty())
|
|
throw Exception("Argument for REGEXP in Merge ENGINE should be a non empty String Literal", ErrorCodes::BAD_ARGUMENTS);
|
|
|
|
return {true, func->arguments->children[0]};
|
|
}
|
|
|
|
auto ast = evaluateConstantExpressionForDatabaseName(node, context_);
|
|
return {false, ast};
|
|
}
|
|
|
|
|
|
void registerStorageMerge(StorageFactory & factory)
|
|
{
|
|
factory.registerStorage("Merge", [](const StorageFactory::Arguments & args)
|
|
{
|
|
/** In query, the name of database is specified as table engine argument which contains source tables,
|
|
* as well as regex for source-table names.
|
|
*/
|
|
|
|
ASTs & engine_args = args.engine_args;
|
|
|
|
if (engine_args.size() != 2)
|
|
throw Exception("Storage Merge requires exactly 2 parameters"
|
|
" - name of source database and regexp for table names.",
|
|
ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
|
|
|
|
auto [is_regexp, database_ast] = StorageMerge::evaluateDatabaseName(engine_args[0], args.getLocalContext());
|
|
|
|
if (!is_regexp)
|
|
engine_args[0] = database_ast;
|
|
|
|
String source_database_name_or_regexp = database_ast->as<ASTLiteral &>().value.safeGet<String>();
|
|
|
|
engine_args[1] = evaluateConstantExpressionAsLiteral(engine_args[1], args.getLocalContext());
|
|
String table_name_regexp = engine_args[1]->as<ASTLiteral &>().value.safeGet<String>();
|
|
|
|
return std::make_shared<StorageMerge>(
|
|
args.table_id, args.columns, args.comment, source_database_name_or_regexp, is_regexp, table_name_regexp, args.getContext());
|
|
},
|
|
{
|
|
.supports_schema_inference = true
|
|
});
|
|
}
|
|
|
|
NamesAndTypesList StorageMerge::getVirtuals() const
|
|
{
|
|
NamesAndTypesList virtuals{{"_database", std::make_shared<DataTypeString>()}, {"_table", std::make_shared<DataTypeString>()}};
|
|
|
|
auto first_table = getFirstTable([](auto && table) { return table; });
|
|
if (first_table)
|
|
{
|
|
auto table_virtuals = first_table->getVirtuals();
|
|
virtuals.insert(virtuals.end(), table_virtuals.begin(), table_virtuals.end());
|
|
}
|
|
|
|
return virtuals;
|
|
}
|
|
}
|