Click House

Connectivity Summary

Click House is the Column oriented Database Management System for Online Analytics Processing of Queries (OAPL).  

The connectivity to Click House is via JDBC driver, which is included in the platform.

The drivers used by the connector are given below:

Driver / API: ClickHouse JDBC driver

Version: 1.0 (latest version is 0.31)

Details: Is JDBC 0.2.4

https://mvnrepository.com/artifact/ru.yandex.clickhouse/clickhouse-jdbc/0.2.4

Connector Capabilities

The connector capabilities are shown below:

Crawling

Supported objects for Crawling are:

Supported Objects Supported Data types
Tables, Table Columns, Views, Stored Procedures, Functions, Roles, Users, Permissions, Usage Statistics LONGBLOB, LONGTEXT, TINYTEXT, TEXT, VARCHAR, MEDIUMBLOB, BLOB, TINYBLOB, CHAR, MEDIUMTEX

 

Please see this article Crawling Data for more details on crawling. 

Profiling

Feature

Support

Remarks

Table Profiling

Row count, Columns count, View sample data

 

View Profiling

Row count, Columns count, View sample data

View is treated as a table for profiling purposes

Column Profiling

Min, Max, Null count, distinct, top 50 values

 

Full Profiling 

Supported

 

Sample Profiling

Supported

 

Please see Profiling Data for more details on profiling.

Lineage Building

Lineage Entities Details

Table lineage

Supported

Column lineage

Supported

Lineage Sources

Stored procedures, functions, views, query logs

Querying

Operation 

Details

Select

Supported

Insert

Supported provided its service account have the permission

Update

Supported provided its service account have the permission

Delete

Supported provided its service account have the permission

Joins within database

Supported

Joins outside database

Not supported

Aggregations

Supported

Group By

Supported

Order By

Supported

By default the service account provided for the connector will be used for any query operations. If the service account has write privileges, then Insert / Update / Delete queries can be executed.

Pre-requisites

To use the connector, the following need to be available:

  • Connection details as specified in the following section should be available.
  • A service account with read privileges.
  • JDBC driver is provided by default.

Connection Details

The following connection settings should be added for connecting to a ClickHouse:

            

  • Database Type: Click House
  • License Type: Standard
  • Connection Name: Select a Connection name for the ClickHouse database. The name that you specify is a reference name to easily identify your ClickHouse database connection in OvalEdge. Example: ClickHouse Connection 
  • Hostname / IP Address: Database instance URL (on-premises/cloud-based)
    Example: ip
  • Port number: 8123 (Default)
  • Sid / Database: Name of the database to connect to.
  • Username: Default (based upon your connection)
  • Password: 0valEdge! (based upon your connection)
  • Driver Name: JDBC driver name for ClickHouse. Need to add in pom.xml. Need not to download external drivers.
    Example: https://mvnrepository.com/artifact/ru.yandex.clickhouse/clickhouse-jdbc/0.2.4
  • Connection String: ClickHouse has a connection string. Set the Connection string toggle button to automatic, to get the details automatically from the credentials provided. Alternatively, you can manually enter the string.
    Format: jdbc:clickhouse://3.84.239.121:8123/test

Once connectivity is established, additional configurations for Crawling and Profiling can be specified.

Property

Details

Crawler configurations

Tables, Views, Columns

By default it is selected true

Crawler rules

Default include tables regex has  regex = (.*) , which can crawl all the tables

Profile Settings

Tables and columns

By default it is selected true

Views and columns

By default it is selected true

Profile Rules

Default include tables regex has  regex = (.*) , which can profile all the tables

Query Log Setting