ClickHouse

ClickHouse is an open-source, column-oriented OLAP database management system designed for real-time analytical queries over large datasets. It uses a massively parallel, vectorized execution engine and supports a wide range of table engines (MergeTree family, Buffer, Distributed, Merge, Dictionary), materialized views, dictionaries, and user-defined functions. ClickHouse is commonly used as the analytical layer for event data, time-series workloads, and observability platforms.

Supported versions

• ClickHouse 22.8 and later
• ClickHouse Cloud

Default hierarchy

In the chart below, you will find the organizational structure of ClickHouse objects. Objects are represented in green and folders are in yellow.

graph LR
    subgraph main[" "]
      Database(Database) --> Tables(Tables)
      Database --> Views(Views)
      Database --> Dictionaries(Dictionaries)
      Tables --> Table(Table)
      Table --> TableColumn(Table Column)
      Table --> Projections(Projections)
      Projections --> Projection(Projection)
      Views --> View(View)
      View --> ViewColumn(View Column)
      Dictionaries --> Dictionary(Dictionary)
      Dictionary --> DictionaryAttribute(Dictionary Attribute)
    end

    subgraph globals["Global"]
      Functions(Functions) --> Function(Function)
    end

    classDef entity fill:#d4edda,stroke:#5cb85c,color:#000
    classDef group fill:#fff3cd,stroke:#f0ad4e,color:#000
    class Database,Table,TableColumn,Projection,View,ViewColumn,Dictionary,DictionaryAttribute,Function entity
    class Tables,Projections,Views,Dictionaries,Functions group

Object types

Dawiso integrates from ClickHouse:

Database

Maps to ClickHouse Database object type.

Source Attribute	Target Attribute in Dawiso
name	Name
comment	Scanned Description
engine	Engine
engine_full	Engine (full)
data_path	Data Path
metadata_path	Metadata Path
uuid	UUID

Table

Maps to ClickHouse Table object type.

Source Attribute	Target Attribute in Dawiso
name	Name
comment	Scanned Description
table_type	Table Type
engine	Engine
engine_full	Engine (full)
partition_key	Partition Key
sorting_key	Sorting Key
primary_key	Primary Key
sampling_key	Sampling Key
storage_policy	Storage Policy
total_rows	Row Count
total_bytes	Total Bytes
size_readable	Size
uuid	UUID
is_temporary	Temporary
metadata_modification_time	Last Modified

Table Column

Maps to ClickHouse Column object type.

Source Attribute	Target Attribute in Dawiso
name	Name
comment	Scanned Description
position	Position
type	Data Type
default_kind	Default Kind
default_expression	Default Expression
is_nullable	Nullable
is_in_partition_key	In Partition Key
is_in_sorting_key	In Sorting Key
is_in_primary_key	In Primary Key
is_in_sampling_key	In Sampling Key
compression_codec	Compression Codec
data_compressed_bytes	Compressed Bytes
data_uncompressed_bytes	Uncompressed Bytes

View

Maps to ClickHouse View object type.

Source Attribute	Target Attribute in Dawiso
name	Name
comment	Scanned Description
view_type	View Type
as_select	Definition
engine	Storage Engine
total_rows	Row Count
size_readable	Size
uuid	UUID
metadata_modification_time	Last Modified

view_type distinguishes regular views, materialized views, and live views.

View Column

Maps to ClickHouse View Column object type.

Source Attribute	Target Attribute in Dawiso
name	Name
comment	Scanned Description
position	Position
type	Data Type
is_nullable	Nullable

Projection

Maps to ClickHouse Projection object type.

Source Attribute	Target Attribute in Dawiso
name	Name
type	Projection Type
sorting_key	Sorting Key
query	Query

Dictionary

Maps to ClickHouse Dictionary object type.

Source Attribute	Target Attribute in Dawiso
name	Name
comment	Scanned Description
status	Status
origin	Origin
type	Dictionary Type
source	Source
lifetime_min	Lifetime Min (s)
lifetime_max	Lifetime Max (s)
element_count	Element Count
bytes_allocated	Bytes Allocated
memory_usage	Memory Usage
query_count	Query Count
hit_rate	Hit Rate
found_rate	Found Rate
uuid	UUID

Dictionary Attribute

Maps to ClickHouse Dictionary Attribute object type.

Source Attribute	Target Attribute in Dawiso
attr_name	Name
attr_position	Position
attr_type	Attribute Type

Function

Maps to ClickHouse Function object type. Only user-defined SQL functions (origin = 'SQLUserDefined') are ingested — built-in functions are excluded.

Source Attribute	Target Attribute in Dawiso
name	Name
description	Scanned Description
origin	Origin
is_aggregate	Aggregate
case_insensitive	Case Insensitive
create_query	Definition