blob: 4ba655a6f6d0707d1020c8fbf59822a4d1a03f19 (
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
|
#pragma once
#include <functional>
#include <Interpreters/Context_fwd.h>
#include <QueryPipeline/Pipe.h>
#include <Storages/KeyDescription.h>
#include <Storages/MergeTree/RangesInDataPart.h>
namespace DB
{
using ReadingInOrderStepGetter = std::function<Pipe(RangesInDataParts)>;
/// Splits parts into layers, each layer will contain parts subranges with PK values from its own range.
/// A separate pipe will be constructed for each layer with a reading step (provided by the reading_step_getter) and a filter for this layer's range of PK values.
/// Will try to produce exactly max_layer pipes but may return less if data is distributed in not a very parallelizable way.
Pipes buildPipesForReadingByPKRanges(
const KeyDescription & primary_key,
ExpressionActionsPtr sorting_expr,
RangesInDataParts parts,
size_t max_layers,
ContextPtr context,
ReadingInOrderStepGetter && reading_step_getter);
}
|
