AnalyticDB for PostgreSQL connector - Realtime Compute for Apache Flink

This topic describes how to use the AnalyticDB for PostgreSQL connector.

Background information

AnalyticDB for PostgreSQL is a data warehouse for massively parallel processing (MPP). It provides online analysis services for a large amount of data.

The following table describes the capabilities supported by the AnalyticDB for PostgreSQL connector.

Item	Description
Table type	Dimension table and result table
Running mode	Streaming mode and batch mode.
Data format	N/A
Metric	Metrics for result tables numRecordsOut numRecordsOutPerSecond numBytesOut numBytesOutPerSecond currentSendTime Metrics for dimension tables: none Note For more information about the metrics, see Metrics.
API type	SQL
Data update or deletion in a result table	Supported

Prerequisites

An AnalyticDB for PostgreSQL instance and an AnalyticDB for PostgreSQL table are created. For more information, see Create an instance and CREATE TABLE.
An IP address whitelist is configured for the AnalyticDB for PostgreSQL instance. For more information, see Configure an IP address whitelist.

Limits

Only Realtime Compute for Apache Flink that uses Ververica Runtime (VVR) 6.0.0 or later supports the AnalyticDB for PostgreSQL connector.
Only Realtime Compute for Apache Flink that uses VVR 8.0.1 or later supports AnalyticDB for PostgreSQL V7.0.
Self-managed PostgreSQL databases are not supported.

Syntax

CREATE TABLE adbpg_table (
 id INT,
 len INT,
 content VARCHAR, 
 PRIMARY KEY(id)
) WITH (
 'connector'='adbpg',
 'url'='jdbc:postgresql://<Address>:<PortId>/<DatabaseName>',
 'tableName'='<yourDatabaseTableName>',
 'userName'='<yourDatabaseUserName>',
 'password'='<yourDatabasePassword>'
);

Parameters in the WITH clause

Category	Parameter	Description	Data type	Required	Default value	Remarks
Common parameters	connector	The type of the table.	STRING	Yes	No default value	Set the value to adbpg.
	url	The Java Database Connectivity (JDBC) URL of the database.	STRING	Yes	No default value	The URL is in the `jdbc:postgresql://<Address>:<PortId>/<DatabaseName>` format.
	tableName	The name of the table in the database.	STRING	Yes	No default value	N/A.
	userName	The username that is used to access the AnalyticDB for PostgreSQL database.	STRING	Yes	No default value	N/A.
	password	The password that is used to access the AnalyticDB for PostgreSQL database.	STRING	Yes	No default value	N/A.
	maxRetryTimes	The maximum number of retries that are allowed to write data to the table if a data writing attempt fails.	INTEGER	No	3	N/A.
	targetSchema	The name of the schema.	STRING	No	public	N/A.
	caseSensitive	Specifies whether to enable case sensitivity.	STRING	No	false	Valid values: true: Case sensitivity is enabled. false: Case sensitivity is disabled. This is the default value.
	connectionMaxActive	The maximum number of connections in the connection pool.	INTEGER	No	5	The system automatically releases idle connections to the database service. Important If this parameter is set to an excessively large value, the number of server connections may be abnormal.
Parameters only for result tables	retryWaitTime	The interval between retries.	INTEGER	No	100	Unit: milliseconds.
	batchSize	The number of data records that can be written to the table at a time.	INTEGER	No	500	N/A.
	flushIntervalMs	The interval at which the cache is cleared.	INTEGER	No	N/A.	If the number of cached data records does not reach the upper limit within the specified period of time, all cached data is written to the result table. Unit: milliseconds.
	writeMode	The write mode in which the system attempts to write data to the table for the first time.	STRING	No	insert	Valid values: insert: Data is directly inserted into the result table. If a conflict occurs, the handling policy is determined by the conflictMode parameter. This is the default value. upsert: Data in the table is automatically updated when a conflict occurs. This value is suitable only for tables that have a primary key.
	conflictMode	The policy based on which a primary key conflict or index conflict is handled when data is inserted into a table.	STRING	No	strict	Valid values: strict: If a conflict occurs, the system reports an error. This is the default value. ignore: If a conflict occurs, the system ignores the conflict. update: If a conflict occurs, the system automatically updates data. This value is suitable for tables that do not have a primary key. This policy reduces the data processing efficiency. upsert: If a conflict occurs, the system automatically updates data in the table. This value is suitable only for tables that have a primary key.
Parameters only for dimension tables	maxJoinRows	The maximum number of rows to join in a row of data.	INTEGER	No	1024	N/A.
	cache	The cache policy.	STRING	No	ALL	Valid values: ALL: All data in the dimension table is cached. This is the default value. Before a deployment runs, the system loads all data in the dimension table to the cache. This way, the cache is searched for all subsequent queries in the dimension table. If the system does not find the data record in the cache, the join key does not exist. The system reloads all data in the cache after cache entries expire. LRU: Partial data in the dimension table is cached. The system searches for data in the cache each time a data record is read from the source table. If the data is not found, the system searches for the data in the physical dimension table. None: No data is cached.
	cacheSize	The maximum number of rows of data that can be cached.	LONG	No	100000	The cacheSize parameter takes effect only when you set the cache parameter to LRU.
	cacheTTLMs	The cache timeout period.	LONG	No	Long.MAX_VALUE	The configuration of the cacheTTLMs parameter varies based on the cache parameter. If the cache parameter is set to LRU, the cacheTTLMs parameter specifies the cache timeout period. By default, cache entries do not expire. If you set the cache parameter to ALL, the cacheTTLMs parameter specifies the interval at which the system refreshes the cache. By default, the cache is not refreshed. Unit: milliseconds.

Data type mappings

Data type of AnalyticDB for PostgreSQL	Data type of Realtime Compute for Apache Flink
BOOLEAN	BOOLEAN
SMALLINT	INT
INT	INT
BIGINT	BIGINT
FLOAT	DOUBLE
VARCHAR	VARCHAR
TEXT	VARCHAR
TIMESTAMP	TIMESTAMP
DATE	DATE

Sample code

Sample code for a result table

CREATE TEMPORARY TABLE datagen_source (
 `name` VARCHAR,
 `age` INT
)
COMMENT 'datagen source table'
WITH (
 'connector' = 'datagen'
);

CREATE TABLE adbpg_sink (
 name VARCHAR,
 age INT
) WITH (
 'connector'='adbpg',
 'url'='jdbc:postgresql://<Address>:<PortId>/<DatabaseName>',
 'tableName'='<yourDatabaseTableName>',
 'userName'='<yourDatabaseUserName>',
 'password'='<yourDatabasePassword>'
);

INSERT INTO adbpg_sink
SELECT * FROM datagen_source;

Sample code for a dimension table

CREATE TEMPORARY TABLE datagen_source(
 a INT,
 b BIGINT,
 c STRING,
 `proctime` AS PROCTIME()
) 
COMMENT 'datagen source table'
WITH (
 'connector' = 'datagen'
};

CREATE TABLE adbpg_dim (
 a INT, 
 b VARCHAR, 
 c VARCHAR
) WITH (
 'connector'='adbpg',
 'url'='jdbc:postgresql://<Address>:<PortId>/<DatabaseName>',
 'tableName'='<yourDatabaseTableName>',
 'userName'='<yourDatabaseUserName>',
 'password'='<yourDatabasePassword>'
);

CREATE TEMPORARY TABLE blackhole_sink(
 a INT,
 b STRING
)
COMMENT 'blackhole sink table'
WITH (
 'connector' = 'blackhole'
);

INSERT INTO blackhole_sink SELECT T.a,H.b
FROM datagen_source AS T JOIN adb_dim FOR SYSTEM_TIME AS OF T.proctime AS H ON T.a = H.a;

Realtime Compute for Apache Flink:AnalyticDB for PostgreSQL connector