blob: d1ceda57f0efe54b1ce4959259f73eee3297025a (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
|
#pragma once
#include <Core/Names.h>
#include <Processors/Chunk.h>
namespace DB
{
/// Interface for entities with key-value semantics.
class IKeyValueEntity
{
public:
IKeyValueEntity() = default;
virtual ~IKeyValueEntity() = default;
/// Get primary key name that supports key-value requests.
/// Primary key can constist of multiple columns.
virtual Names getPrimaryKey() const = 0;
/*
* Get data from storage directly by keys.
*
* @param keys - keys to get data for. Key can be compound and represented by several columns.
* @param out_null_map - output parameter indicating which keys were not found.
* @param required_columns - if we don't need all attributes, implementation can use it to benefit from reading a subset of them.
*
* @return - chunk of data corresponding for keys.
* Number of rows in chunk is equal to size of columns in keys.
* If the key was not found row would have a default value.
*/
virtual Chunk getByKeys(const ColumnsWithTypeAndName & keys, PaddedPODArray<UInt8> & out_null_map, const Names & required_columns) const = 0;
/// Header for getByKeys result
virtual Block getSampleBlock(const Names & required_columns) const = 0;
protected:
/// Names of result columns. If empty then all columns are required.
Names key_value_result_names;
};
}
|
