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27 lines
1.1 KiB
C++
27 lines
1.1 KiB
C++
#pragma once
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#include <Core/Block.h>
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#include <Storages/StorageSnapshot.h>
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namespace DB
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{
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struct ReadFromFormatInfo
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{
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/// Header that will return Source from storage.
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/// It contains all requested columns including virtual columns;
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Block source_header;
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/// Header that will be passed to IInputFormat to read data from file.
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/// It can contain more columns than were requested if format doesn't support
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/// reading subset of columns.
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Block format_header;
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/// Description of columns for format_header. Used for inserting defaults.
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ColumnsDescription columns_description;
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/// The list of requested columns without virtual columns.
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NamesAndTypesList requested_columns;
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/// The list of requested virtual columns.
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NamesAndTypesList requested_virtual_columns;
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};
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/// Get all needed information for reading from data in some input format.
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ReadFromFormatInfo prepareReadingFromFormat(const Strings & requested_columns, const StorageSnapshotPtr & storage_snapshot, bool supports_subset_of_columns);
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}
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