Updated on 2024-09-29 GMT+08:00

GaussDB(DWS) Source Table

Function

DLI reads data of Flink jobs from GaussDB(DWS). GaussDB(DWS) database kernel is compliant with PostgreSQL. The PostgreSQL database can store data of more complex types and delivers space information services, multi-version concurrent control (MVCC), and high concurrency. It applies to location applications, financial insurance, and e-commerce.

GaussDB(DWS) is an online data processing database based on the cloud infrastructure and platform and helps you mine and analyze massive sets of data.

Prerequisites

  • Ensure that you have created a GaussDB(DWS) cluster using your account.

    For details about how to create a GaussDB(DWS) cluster, see "Creating a Cluster" in Data Warehouse Service Management Guide.

  • A GaussDB(DWS) database table has been created.
  • An enhanced datasource connection has been created for DLI to connect to GaussDB(DWS) clusters, so that jobs can run on the dedicated queue of DLI and you can set the security group rules as required.
  • You have set up an enhanced datasource connection. For details, see Enhanced Datasource Connections in the Data Lake Insight User Guide.
  • For details about how to configure security group rules, see Security Group Overview in the Virtual Private Cloud User Guide.

Syntax

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create table dwsSource (
  attr_name attr_type 
  (',' attr_name attr_type)* 
  (','PRIMARY KEY (attr_name, ...) NOT ENFORCED)
  (',' watermark for rowtime_column_name as watermark-strategy_expression)
)
with (
  'connector.type' = 'gaussdb',
  'connector.url' = '',
  'connector.table' = '',
  'connector.username' = '',
  'connector.password' = ''
);

Parameters

Table 1 Parameter description

Parameter

Mandatory

Description

connector.type

Yes

Connector type. Set this parameter to gaussdb.

connector.url

Yes

JDBC connection address. The format is jdbc:postgresql://${ip}:${port}/${dbName}. If the database version is later than 8.1.0, the value format is jdbc:gaussdb://${ip}:${port}/${dbName}.

connector.table

Yes

Name of the table to be operated. If the GaussDB(DWS) table is in a schema, the format is schema\".\"Table name. For details, see the Example.

connector.driver

No

JDBC connection driver. The default value is org.postgresql.Driver.

If the database version is later than 8.1.0, the value is com.huawei.gauss200.jdbc.Driver.

connector.username

No

Database authentication user name. This parameter must be configured in pair with connector.password.

connector.password

No

Database authentication password. This parameter must be configured in pair with connector.username.

connector.read.partition.column

No

Name of the column used to partition the input

This parameter is mandatory if connector.read.partition.lower-bound, connector.read.partition.upper-bound, and

connector.read.partition.num are configured.

connector.read.partition.lower-bound

No

Lower bound of values to be fetched for the first partition

This parameter is mandatory if connector.read.partition.column, connector.read.partition.upper-bound, and

connector.read.partition.num are configured.

connector.read.partition.upper-bound

No

Upper bound of values to be fetched for the last partition

This parameter is mandatory if connector.read.partition.column, connector.read.partition.lower-bound, and

connector.read.partition.num are configured.

connector.read.partition.num

No

Number of partitions to be created

This parameter is mandatory if connector.read.partition.column, connector.read.partition.upper-bound, and

connector.read.partition.upper-bound are configured.

connector.read.fetch-size

No

Number of rows fetched from the database each time The default value is 0, indicating the hint is ignored.

Example

  • If you use the gsjdbc4 driver for connection, set connector.driver to org.postgresql.Driver. You can omit this parameter because the gsjdbc4 driver is the default one.

    Create table dwsSource with data fetched from the car_info table that is not in a schema:

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    create table dwsSource(
      car_id STRING,
      car_owner STRING,
      car_brand STRING,
      car_speed INT
    ) with (
      'connector.type' = 'gaussdb',
      'connector.url' = 'jdbc:postgresql://xx.xx.xx.xx:8000/xx',
      'connector.table' = 'car_info',
      'connector.username' = 'xx',
      'connector.password' = 'xx'
    );
    

    Create table dwsSource with data fetched from GaussDB(DWS) table test that is in a schema named test_schema:

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    create table dwsSource(
      car_id STRING,
      car_owner STRING,
      car_brand STRING,
      car_speed INT
    ) with (
      'connector.type' = 'gaussdb',
      'connector.url' = 'jdbc:postgresql://xx.xx.xx.xx:8000/xx',
      'connector.table' = 'test_schema\".\"test',
      'connector.username' = 'xx',
      'connector.password' = 'xx'
    );
    
  • If you use the gsjdbc200 driver for connection, set connector.driver to com.huawei.gauss200.jdbc.Driver.
    Create table dwsSource with data fetched from GaussDB(DWS) table test that is in a schema named ads_game_sdk_base:
    create table dwsSource(
      car_id STRING,
      car_owner STRING,
      car_brand STRING,
      car_speed INT
    ) with (
      'connector.type' = 'gaussdb',
      'connector.table' = 'ads_game_sdk_base\".\"test',
      'connector.driver' = 'com.huawei.gauss200.jdbc.Driver',
      'connector.url' = 'jdbc:gaussdb://xx.xx.xx.xx:8000/xx',
      'connector.username' = 'xx',
      'connector.password' = 'xx'
    );