blob: 778fa462364a081a4aa8bb6f2f1685de8ea0d915 (
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
|
#pragma once
#include <Interpreters/DatabaseAndTableWithAlias.h>
#include <Interpreters/InDepthNodeVisitor.h>
namespace DB
{
class ASTFunction;
/** Replace predicate having Date/DateTime converters with their preimages to improve performance.
* Given a Date column c, toYear(c) = 2023 -> c >= '2023-01-01' AND c < '2024-01-01'
* Or if c is a DateTime column, toYear(c) = 2023 -> c >= '2023-01-01 00:00:00' AND c < '2024-01-01 00:00:00'.
* The similar optimization also applies to other converters.
*/
class OptimizeDateOrDateTimeConverterWithPreimageMatcher
{
public:
struct Data
{
const TablesWithColumns & tables;
ContextPtr context;
};
static void visit(ASTPtr & ast, Data & data)
{
if (const auto * ast_function = ast->as<ASTFunction>())
visit(*ast_function, ast, data);
}
static void visit(const ASTFunction & function, ASTPtr & ast, const Data & data);
static bool needChildVisit(ASTPtr & ast, ASTPtr & child);
};
using OptimizeDateOrDateTimeConverterWithPreimageVisitor = InDepthNodeVisitor<OptimizeDateOrDateTimeConverterWithPreimageMatcher, true>;
}
|
