PostgreSql

JDBC PostgreSql Sink Connector

Description​

Write data through jdbc. Support Batch mode and Streaming mode, support concurrent writing, support exactly-once semantics (using XA transaction guarantee).

Key Features​

• exactly-once

• cdc

Use Xa transactions to ensure exactly-once. So only support exactly-once for the database which is support Xa transactions. You can set is_exactly_once=true to enable it.

Supported DataSource Info​

Datasource	Supported Versions	Driver	Url
PostgreSQL	Different dependency version has different driver class.	org.postgresql.Driver	jdbc:postgresql://localhost:5432/test
PostgreSQL	If you want to manipulate the GEOMETRY type in PostgreSQL.	org.postgresql.Driver	jdbc:postgresql://localhost:5432/test

Data Type Mapping​

PostgreSQL Data Type	Nexus Data Type
BOOL	BOOLEAN
_BOOL	ARRAY<BOOLEAN>
BYTEA	BYTES
_BYTEA	ARRAY<TINYINT>
INT2 SMALLSERIAL INT4 SERIAL	INT
_INT2 _INT4	ARRAY<INT>
INT8 BIGSERIAL	BIGINT
_INT8	ARRAY<BIGINT>
FLOAT4	FLOAT
_FLOAT4	ARRAY<FLOAT>
FLOAT8	DOUBLE
_FLOAT8	ARRAY<DOUBLE>
NUMERIC(Get the designated column's specified column size>0)	DECIMAL(Get the designated column's specified column size,Gets the number of digits in the specified column to the right of the decimal point)
NUMERIC(Get the designated column's specified column size<0)	DECIMAL(38, 18)
BPCHAR CHARACTER VARCHAR TEXT GEOMETRY GEOGRAPHY JSON JSONB UUID	STRING
_BPCHAR _CHARACTER _VARCHAR _TEXT	ARRAY<STRING>
TIMESTAMP	TIMESTAMP
TIME	TIME
DATE	DATE
OTHER DATA TYPES	NOT SUPPORTED YET

Options​

Name	Type	Required	Default	Description
url	String	Yes	-	The URL of the JDBC connection. Refer to a case: jdbc:postgresql://localhost:5432/test if you would use json or jsonb type insert please add jdbc url stringtype=unspecified option
driver	String	Yes	-	The jdbc class name used to connect to the remote data source, if you use PostgreSQL the value is org.postgresql.Driver.
user	String	No	-	Connection instance user name
password	String	No	-	Connection instance password
query	String	No	-	Use this sql write upstream input datas to database. e.g INSERT ...,query have the higher priority
database	String	No	-	Use this database and table-name auto-generate sql and receive upstream input datas write to database. This option is mutually exclusive with query and has a higher priority.
table	String	No	-	Use database and this table-name auto-generate sql and receive upstream input datas write to database. This option is mutually exclusive with query and has a higher priority.The table parameter can fill in the name of an unwilling table, which will eventually be used as the table name of the creation table, and supports variables (${table_name}, ${schema_name}). Replacement rules: ${schema_name} will replace the SCHEMA name passed to the target side, and ${table_name} will replace the name of the table passed to the table at the target side.
primary_keys	Array	No	-	This option is used to support operations such as insert, delete, and update when automatically generate sql.
support_upsert_by_query_primary_key_exist	Boolean	No	false	Choose to use INSERT sql, UPDATE sql to process update events(INSERT, UPDATE_AFTER) based on query primary key exists. This configuration is only used when database unsupport upsert syntax. Note: that this method has low performance
connection_check_timeout_sec	Int	No	30	The time in seconds to wait for the database operation used to validate the connection to complete.
max_retries	Int	No	0	The number of retries to submit failed (executeBatch)
batch_size	Int	No	1000	For batch writing, when the number of buffered records reaches the number of batch_size or the time reaches checkpoint.interval , the data will be flushed into the database
is_exactly_once	Boolean	No	false	Whether to enable exactly-once semantics, which will use Xa transactions. If on, you need to set xa_data_source_class_name.
generate_sink_sql	Boolean	No	false	Generate sql statements based on the database table you want to write to.
xa_data_source_class_name	String	No	-	The xa data source class name of the database Driver, for example, PostgreSQL is org.postgresql.xa.PGXADataSource, and please refer to appendix for other data sources
max_commit_attempts	Int	No	3	The number of retries for transaction commit failures
transaction_timeout_sec	Int	No	-1	The timeout after the transaction is opened, the default is -1 (never timeout). Note that setting the timeout may affect exactly-once semantics
auto_commit	Boolean	No	true	Automatic transaction commit is enabled by default
field_ide	String	No	-	Identify whether the field needs to be converted when synchronizing from the source to the sink. ORIGINAL indicates no conversion is needed;UPPERCASE indicates conversion to uppercase;LOWERCASE indicates conversion to lowercase.
properties	Map	No	-	Additional connection configuration parameters,when properties and URL have the same parameters, the priority is determined by the specific implementation of the driver. For example, in MySQL, properties take precedence over the URL.
common-options		no	-	Sink plugin common parameters, please refer to Sink Common Options for details
schema_save_mode	Enum	no	CREATE_SCHEMA_WHEN_NOT_EXIST	Before the synchronous task is turned on, different treatment schemes are selected for the existing surface structure of the target side.
data_save_mode	Enum	no	APPEND_DATA	Before the synchronous task is turned on, different processing schemes are selected for data existing data on the target side.
custom_sql	String	no	-	When data_save_mode selects CUSTOM_PROCESSING, you should fill in the CUSTOM_SQL parameter. This parameter usually fills in a SQL that can be executed. SQL will be executed before synchronization tasks.
enable_upsert	Boolean	No	true	Enable upsert by primary_keys exist, If the task has no key duplicate data, setting this parameter to false can speed up data import

table [string]​

Use database and this table-name auto-generate sql and receive upstream input datas write to database.

This option is mutually exclusive with query and has a higher priority.

The table parameter can fill in the name of an unwilling table, which will eventually be used as the table name of the creation table, and supports variables (${table_name}, ${schema_name}). Replacement rules: ${schema_name} will replace the SCHEMA name passed to the target side, and ${table_name} will replace the name of the table passed to the table at the target side.

for example:

1. ${schema_name}.${table_name} _test

2. dbo.tt_${table_name} _sink

3. public.sink_table

schema_save_mode[Enum]​

Before the synchronous task is turned on, different treatment schemes are selected for the existing surface structure of the target side. Option introduction： RECREATE_SCHEMA ：Will create when the table does not exist, delete and rebuild when the table is saved CREATE_SCHEMA_WHEN_NOT_EXIST ：Will Created when the table does not exist, skipped when the table is saved ERROR_WHEN_SCHEMA_NOT_EXIST ：Error will be reported when the table does not exist

data_save_mode[Enum]​

Before the synchronous task is turned on, different processing schemes are selected for data existing data on the target side. Option introduction： DROP_DATA： Preserve database structure and delete data APPEND_DATA：Preserve database structure, preserve data CUSTOM_PROCESSING：User defined processing ERROR_WHEN_DATA_EXISTS：When there is data, an error is reported

custom_sql[String]​

When data_save_mode selects CUSTOM_PROCESSING, you should fill in the CUSTOM_SQL parameter. This parameter usually fills in a SQL that can be executed. SQL will be executed before synchronization tasks.

Tips​

If partition_column is not set, it will run in single concurrency, and if partition_column is set, it will be executed in parallel according to the concurrency of tasks.

Task Example​

Simple:​

This example defines a Nexus synchronization task that automatically generates data through FakeSource and sends it to JDBC Sink. FakeSource generates a total of 16 rows of data (row.num=16), with each row having two fields, name (string type) and age (int type). The final target table is test_table will also be 16 rows of data in the table. Before run this job, you need create database test and table test_table in your PostgreSQL.

# Defining the runtime environment
env {
  parallelism = 1
  job.mode = "BATCH"
}

source {
  FakeSource {
    parallelism = 1
    result_table_name = "fake"
    row.num = 16
    schema = {
      fields {
        name = "string"
        age = "int"
      }
    }
  }
  # If you would like to get more information about how to configure Nexus and see full list of source plugins,
  # please go to source page
}

transform {
  # If you would like to get more information about how to configure Nexus and see full list of transform plugins,
    # please go to transform page
}

sink {
    jdbc {
       # if you would use json or jsonb type insert please add jdbc url stringtype=unspecified option
        url = "jdbc:postgresql://localhost:5432/test"
        driver = "org.postgresql.Driver"
        user = root
        password = 123456
        query = "insert into test_table(name,age) values(?,?)"
     }
  # If you would like to get more information about how to configure Nexus and see full list of sink plugins,
  # please go to sink page
}

Generate Sink SQL​

This example not need to write complex sql statements, you can configure the database name table name to automatically generate add statements for you

sink {
    Jdbc {
        # if you would use json or jsonb type insert please add jdbc url stringtype=unspecified option
        url = "jdbc:postgresql://localhost:5432/test"
        driver = org.postgresql.Driver
        user = root
        password = 123456
        
        generate_sink_sql = true
        database = test
        table = "public.test_table"
    }
}

Exactly-once :​

For accurate write scene we guarantee accurate once

sink {
    jdbc {
       # if you would use json or jsonb type insert please add jdbc url stringtype=unspecified option
        url = "jdbc:postgresql://localhost:5432/test"
        driver = "org.postgresql.Driver"
    
        max_retries = 0
        user = root
        password = 123456
        query = "insert into test_table(name,age) values(?,?)"
    
        is_exactly_once = "true"
    
        xa_data_source_class_name = "org.postgresql.xa.PGXADataSource"
    }
}

CDC(Change Data Capture) Event​

CDC change data is also supported by us In this case, you need config database, table and primary_keys.

sink {
    jdbc {
        # if you would use json or jsonb type insert please add jdbc url stringtype=unspecified option
        url = "jdbc:postgresql://localhost:5432/test"
        driver = "org.postgresql.Driver"
        user = root
        password = 123456
        
        generate_sink_sql = true
        # You need to configure both database and table
        database = test
        table = sink_table
        primary_keys = ["id","name"]
        field_ide = UPPERCASE
    }
}

Save mode function​

sink {
    Jdbc {
        # if you would use json or jsonb type insert please add jdbc url stringtype=unspecified option
        url = "jdbc:postgresql://localhost:5432/test"
        driver = org.postgresql.Driver
        user = root
        password = 123456
        
        generate_sink_sql = true
        database = test
        table = "public.test_table"
        schema_save_mode = "CREATE_SCHEMA_WHEN_NOT_EXIST"
        data_save_mode="APPEND_DATA"
    }
}