Skip to content


Repository files navigation

ClickHouse input plugin for Embulk

ClickHouse input plugin for Embulk loads records from ClickHouse.


  • Plugin type: input
  • Resume supported: NO


  • driver_path: path to the jar file of the ClickHouse JDBC driver. If not set, the bundled JDBC driver (ClickHouse JDBC Driver TBD) will be used. (string)
  • host: database host name (string, required)
  • port: database port number (integer, 8123)
  • user: database login user name (string)
  • password: database login password (string, default: "")
  • database: destination database name (string, required)
  • buffer_size: see ClickHouse param buffer_size (integer, default: 65535)
  • apache_buffer_size: see ClickHouse param apache_buffer_size (integer, default: 65535)
  • connect_timeout: see ClickHouse param connection_timeout (integer, default: 30000)
  • socket_timeout: see ClickHouse param socket_timeout (integer, default: 10000)
  • data_transfer_timeout: see ClickHouse param data_transfer_timeout (integer, default: 10000)
  • keep_alive_timeout: see ClickHouse param keep_alive_timeout (integer, default: 10000)
  • options: extra JDBC properties (hash, default: {})
  • If you write SQL directly,
    • query: SQL to run (string)
    • use_raw_query_with_incremental: If true, you can write optimized query using prepared statement by yourself. See Use incremental loading with raw query for more detail (boolean, default: false)
  • If query is not set,
    • table: destination table name (string, required)
    • select: expression of select (e.g. id, created_at) (string, default: "*")
    • where: WHERE condition to filter the rows (string, default: no-condition)
    • order_by: expression of ORDER BY to sort rows (e.g. created_at DESC, id ASC) (string, default: not sorted)
  • default_timezone: If the sql type of a column is date/time/datetime and the embulk type is string, column values are formatted int this default_timezone. You can overwrite timezone for each columns using column_options option. (string, default: UTC)
  • column_options: advanced: a key-value pairs where key is a column name and value is options for the column.
    • value_type: embulk get values from database as this value_type. Typically, the value_type determines getXXX method of java.sql.PreparedStatement. (string, default: depends on the sql type of the column. Available values options are: long, double, float, decimal, boolean, string, json, date, time, timestamp, array) See below for hstore column.
    • type: Column values are converted to this embulk type. Available values options are: boolean, long, double, string, json, timestamp). By default, the embulk type is determined according to the sql type of the column (or value_type if specified). In default, 'UInt64' values are converted to long, but too large values can't be converted to long. So, please use string or json
    • timestamp_format: If the sql type of the column is date/time/datetime and the embulk type is string, column values are formatted by this timestamp_format. And if the embulk type is timestamp, this timestamp_format may be used in the output plugin. For example, stdout plugin use the timestamp_format, but csv formatter plugin doesn't use. (string, default : %Y-%m-%d for date, %H:%M:%S for time, %Y-%m-%d %H:%M:%S for timestamp)
    • timezone: If the sql type of the column is date/time/datetime and the embulk type is string, column values are formatted in this timezone. (string, value of default_timezone option is used by default)
  • after_select: if set, this SQL will be executed after the SELECT query in the same transaction.


  type: clickhouse
  host: localhost
  database: my_database
  table: my_table
  select: "col1, col2, col3"
  where: "col4 != 'a'"
  order_by: "col1 DESC"

This configuration will generate following SQL:

SELECT col1, col2, col3
FROM "my_table"
WHERE col4 != 'a'

Advanced configuration:

  type: clickhouse
  driver_path: ./path/to/clickhouse-jdbc-x.y.jar
  database: my_database
  host: localhost
  socket_timeout:  1000000
  query: SELECT * from my_table
    col1: {type: string} # If col1 include too large integer value(UInt64), convert to string.


$ ./gradlew gem


ClickHouse input plugin for Embulk







No releases published