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
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
#pragma once
#include <base/types.h>
#include <memory>
#include <vector>
#include <Core/Field.h>
#include <Interpreters/ExpressionActions.h>
#include <Parsers/IAST_fwd.h>
#include <Storages/ColumnsDescription.h>
#include <Common/NamePrompter.h>
namespace DB
{
/// Description of non-primary index for Storage
struct IndexDescription
{
/// Definition AST of index
ASTPtr definition_ast;
/// List of expressions for index calculation
ASTPtr expression_list_ast;
/// Index name
String name;
/// Index type (minmax, set, bloom filter, etc.)
String type;
/// Prepared expressions for index calculations
ExpressionActionsPtr expression;
/// Index arguments, for example probability for bloom filter
FieldVector arguments;
/// Names of index columns (not to be confused with required columns)
Names column_names;
/// Data types of index columns
DataTypes data_types;
/// Sample block with index columns. (NOTE: columns in block are empty, but not nullptr)
Block sample_block;
/// Index granularity, make sense for skip indices
size_t granularity;
/// Parse index from definition AST
static IndexDescription getIndexFromAST(const ASTPtr & definition_ast, const ColumnsDescription & columns, ContextPtr context);
IndexDescription() = default;
/// We need custom copy constructors because we don't want
/// unintentionaly share AST variables and modify them.
IndexDescription(const IndexDescription & other);
IndexDescription & operator=(const IndexDescription & other);
/// Recalculate index with new columns because index expression may change
/// if something change in columns.
void recalculateWithNewColumns(const ColumnsDescription & new_columns, ContextPtr context);
};
/// All secondary indices in storage
struct IndicesDescription : public std::vector<IndexDescription>, IHints<1, IndicesDescription>
{
/// Index with name exists
bool has(const String & name) const;
/// Convert description to string
String toString() const;
/// Parse description from string
static IndicesDescription parse(const String & str, const ColumnsDescription & columns, ContextPtr context);
/// Return common expression for all stored indices
ExpressionActionsPtr getSingleExpressionForIndices(const ColumnsDescription & columns, ContextPtr context) const;
Names getAllRegisteredNames() const override;
};
}
|
