Google Cloud PostgreSQL

Last updated on Sep 19, 2023

Prerequisites

IP address or host name of your PostgreSQL server is available.
The PostgreSQL version is 9.4 or higher.
Hevo’s IP addresses are whitelisted.
SELECT, USAGE, and CONNECT privileges are granted to the database user.
You are assigned the Team Administrator, Team Collaborator, or Pipeline Administrator role in Hevo to create the Pipeline.
If the Pipeline mode is Logical Replication:
- Log-based incremental replication is enabled.
- PostgreSQL database instance is a master instance.
  
  Note: PostgreSQL does not support logical replication for the read replica.

Perform the following steps to configure your Google Cloud PostgreSQL Source:

Set up Log-based Incremental Replication (optional)

Note: If you are not using Logical Replication, skip this step.

PostgreSQL (version 9.4 and above) supports logical replication by writing additional information to its Write Ahead Logs (WALs).

To configure logical replication:

Go to the Google Cloud SQL instance.
Click the More icon next to the PostgreSQL instance and click Edit.
Scroll down to the Flags section.
Click the More icon next to the PostgreSQL instance name and click Edit.
Scroll down to the Flags section.
Click the drop-down next to Flags and then click Add Flag.

Select all four flags from the drop-down menu. Specify their values as follows:

Setting	Value	Description
`cloudsql.enable_pglogical`	On	The setting to enable or disable the `pglogical` extension. Default value: Off.
`cloudsql.logical_decoding`	On	The setting to enable or disable logical replication. Default value: Off.
`max_replication_slots`	10	The number of clients that can connect to the server. Default value: 10.
`max_wal_senders`	10	The number of processes that can simultaneously transmit the WAL log. Default value: 10.
`wal_sender_timeout`	0	The time, in seconds, after which PostgreSQL terminates the replication connections due to inactivity. Default value: 60 seconds. You must set the value to 0 so that the connections are never terminated and your Pipeline does not fail. You can use the following query to check the value configured for the parameter: `show wal_sender_timeout`

Click Save. The settings you configured are displayed under the Flags section.

Whitelist Hevo’s IP Addresses

You need to whitelist the Hevo IP addresses for your region to enable Hevo to connect to your PostgreSQL database. To do this:

Access the Google Cloud console and click on your PostgeSQL instance ID.
In the left navigation pane, click Connections.
Select the Public IP check box to activate access on any custom IP address.
Click Add Network, and include the list of Hevo IP addresses available for your region.
Repeat the above step for all the network addresses you want to add.
Click Save. You can see Hevo’s IP addresses under Authorized networks.

Create a Replication User and Grant Privileges

While using logical replication in Google Cloud PostgreSQL, the user must have the cloudsqlsuperuser role. This role is needed to run the CREATE EXTENSION command.

Create a PostgreSQL user with REPLICATION privileges as follows:

Log in to your PostgreSQL database using any SQL client like DataGrip as a super admin and run the following commands:
```
 CREATE USER replication_user WITH REPLICATION
 IN ROLE cloudsqlsuperuser LOGIN PASSWORD 'secret';
```
Alternatively, set this attribute for an existing user as follows:
```
 ALTER USER existing_user WITH REPLICATION;
```

Enter the following commands to provide access to the database user:

 GRANT CONNECT ON DATABASE <database_name> TO <database_username>;
 GRANT USAGE ON SCHEMA <schema_name> TO <database_username>;

Alter the schema’s default privileges to grant SELECT privileges on tables to the database user:

 ALTER DEFAULT PRIVILEGES IN SCHEMA <schema_name> GRANT SELECT ON TABLES TO <database_username>;

Specify Google Cloud PostgreSQL Connection Settings

In the Configure your Google Cloud PostgreSQL Source page, specify the following:
- Pipeline Name: A unique name for your Pipeline, not exceeding 255 characters.
- Database Host: The Google Cloud PostgreSQL host’s IP address or DNS. For example, 35.220.150.0 .
- Database Port: The port on which your PostgreSQL server is listening for connections. Default value: 5432.
- Database User: The read-only user who has the permissions to read tables in your database.
- Database Password: The password for the read-only user.
- Select an Ingestion Mode: The desired mode by which you want to ingest data from the Source. This section is expanded by default. However, you can collapse the section by clicking SEE LESS. Default value: Logical Replication.
  
  The available Ingestion Modes are Logical Replication, Table, and Custom SQL. Logical Replication is the recommended ingestion mode and selected by default.
  - For ingestion mode as Table, refer to section, Object Settings for steps to configure the objects to be replicated.
  - For ingestion mode as Logical Replication, follow the steps provided in each PostgreSQL variant document to set up logical replication.
  Note:
  - PostgreSQL does not support logical replication for the read replica.
  - For Custom SQL ingestion mode, all Events loaded to the Destination are billable.
- Database Name: The database that you wish to replicate.
- Connection Settings:
  - Connect through SSH: Enable this option to connect to Hevo using an SSH tunnel, instead of directly connecting your PostgreSQL database host to Hevo. This provides an additional level of security to your database by not exposing your PostgreSQL setup to the public. Read Connecting Through SSH.
    
    If this option is disabled, you must whitelist Hevo’s IP addresses. Refer to the content for your PostgreSQL variant for steps to do this.
  - Use SSL: Enable it to use SSL encrypted connection. You should also enable this if you are using Heroku PostgreSQL databases. To enable this, specify the following:
    - CA File: The file containing the SSL server certificate authority (CA).
    - Client Certificate: The client public key certificate file.
    - Client Key: The client private key file.
- Advanced Settings
  - Load Historical Data: Applicable for Pipelines with Logical Replication mode. If this option is enabled, the entire table data is fetched during the first run of the Pipeline. If disabled, Hevo loads only the data that was written in your database after the time of creation of the Pipeline.
  - Merge Tables: Applicable for Pipelines with Logical Replication mode. If this option is enabled, Hevo merges tables with the same name from different databases while loading the data to the warehouse. Hevo loads the Database Name field with each record. If disabled, the database name is prefixed to each table name. Read How does the Merge Tables feature work?.
  - Include New Tables in the Pipeline: Applicable for all Ingestion modes except Custom SQL. If enabled, Hevo automatically ingests data from tables created in the Source after the Pipeline has been built. These may include completely new tables or previously deleted tables that have been re-created in the Source. If disabled, new and re-created tables are not ingested automatically. They are added in SKIPPED state in the objects list, in the Pipeline Overview page. You can update their status to INCLUDED to ingest data. You can change this setting later. You can include these objects post-Pipeline creation to ingest data.
Click TEST CONNECTION. This button is enabled once you specify all the mandatory fields. Hevo’s underlying connectivity checker validates the connection settings you provide.
Click TEST & CONTINUE to proceed for setting up the Destination. This button is enabled once you specify all the mandatory fields.

Object Settings

Object settings must be configured if the Ingestion mode is Table.

To do this:

Once your respective Source connection settings are specified as per section Specify Google Cloud PostgreSQL Connection Settings above, select the objects to be replicated in the SELECT the Objects you want to replicate page, and then click CONTINUE.

Note: Each object represents a table in your database.
In the CONFIGURE SOURCE OBJECTS page, specify the query mode to be used for each selected object.

Additional Information

Read the detailed Hevo documentation for the following related topics:

Source Considerations

If you add a column with a default value to a table in PostgreSQL, entries with it are created in the WAL only for the rows that are added or updated after the column is added. As a result, in the case of log-based Pipelines, Hevo cannot capture the column value for the unchanged rows. To capture those values, you need to:
- Restart the historical load for the respective object.
- Run a query in the Destination to add the column and its value to all rows.

Limitations

The data type Array in the Source is automatically mapped to Varchar at the Destination. No other mapping is currently supported.
Hevo does not support data replication from foreign tables, temporary tables, and views.

Revision History

Refer to the following table for the list of key updates made to this page:

Date	Release	Description of Change
Sep-19-2023	NA	Updated section, Limitations to add information about Hevo not supporting data replication from certain tables.
Jun-26-2023	NA	Added section, Source Considerations.
Apr-21-2023	NA	Updated section, Specify Google Cloud PostgreSQL Connection Settings to add a note to inform users that all loaded Events are billable for Custom SQL mode-based Pipelines.
Mar-09-2023	2.09	Updated section, Specify Google Cloud PostgreSQL Connection Settings to mention about SEE MORE in the Select an Ingestion Mode section.
Dec-19-2022	2.04	Updated section, Specify Google Cloud PostgreSQL Connection Settings to add information that you must specify all fields to create a Pipeline.
Dec-07-2022	2.03	Updated section, Specify Google Cloud PostgreSQL Connection Settings to mention about including skipped objects post-Pipeline creation.
Dec-07-2022	2.03	Updated section, Specify Google Cloud PostgreSQL Connection Settings to mention about the connectivity checker.
Jul-04-2022	NA	- Added sections, Specify Google Cloud PostgreSQL Connection Settings and Object Settings.
Mar-07-2022	1.83	Updated the section, Prerequisites with a note about the logical replication.
Jan-24-2022	1.80	Removed from Limitations that Hevo does not support UUID datatype as primary key.
Dec-20-2021	1.78	Updated section, Set up Log-based Incremental Replication.
Sep-09-2021	1.71	- Updated the section, Limitations to include information about columns with the UUID data type not being supported as a primary key. - Added WAL replication mode in the Prerequisites section. - Replaced the section Grant Privileges to the User with Create a Replication User and Grant Privileges.
Jun-14-2021	1.65	Updated the Grant Privileges to the User section to include latest commands.