Generic PostgreSQL

Last updated on May 30, 2024

Starting Release 2.19, Hevo has stopped supporting XMIN as a query mode for all variants of the PostgreSQL Source. As a result, you will not be able to create new Pipelines using this query mode. This change does not affect existing Pipelines. However, you will not be able to change the query mode to XMIN for any objects currently ingesting data using other query modes.

PostgreSQL is a highly stable database management system, used as the primary data store or data warehouse for many web, mobile, geospatial, and analytics applications. Generic PostgreSQL represents a self-hosted PostgreSQL server.

You can ingest data from your PostgreSQL database using Hevo Pipelines and replicate it to a Destination of your choice.


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.

  • PostgreSQL does not support logical replication on read replicas. To enable log-based replication, you must select the primary database instance.

  • When you delete a row in the Source table, its XMIN value is deleted as well. As a result, for Pipelines created with the XMIN ingestion mode, Hevo cannot track deletes in the Source object(s). To capture deletes, you need to restart the historical load for the respective object.

  • XMIN is a system-generated column in PostgreSQL, and it cannot be indexed. Hence, to identify the updated rows in Pipelines created with the XMIN ingestion mode, Hevo scans the entire table. This action may lead to slower data ingestion and increased processing overheads on your PostgreSQL database host. Due to this, Hevo recommends that you create the Pipeline in the Logical Replication mode.

Note: The XMIN limitations specified above are applicable only to Pipelines created using the XMIN ingestion mode, which is currently available for Early Access.


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.

  • If your Source data has indexes (indices) and constraints, you must recreate them in your Destination table, as Hevo does not replicate them from the Source. It only creates the existing primary keys.

  • Hevo does not set the __hevo_marked_deleted field to True for data deleted from the Source table using the TRUNCATE command. This could result in a data mismatch between the Source and Destination tables.


See Also


Revision History

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

Date Release Description of Change
May-30-2024 NA Updated section, Grant privileges to the user to add all the necessary permissions.
Apr-29-2024 NA Updated section, Specify PostgreSQL Connection Settings to include more detailed steps.
Mar-18-2024 2.21.2 Updated section, Specify PostgreSQL Connection Settings to add information about the Load all CA certificates option.
Mar-05-2024 2.21 Added the Data Replication section.
Feb-05-2024 NA Updated sections, Specify PostgreSQL Connection Settings and Object and Query Mode Settings to add information about the XMIN ingestion mode.
Jan-22-2024 2.19.2 Updated section, Object and Query Mode Settings to add a note about the enhanced object selection flow available for log-based Pipelines.
Jan-10-2024 NA - Updated section, Source Considerations to add information about limitations of XMIN query mode.
- Removed mentions of XMIN as a query mode.
Nov-03-2023 NA Renamed section, Object Settings to Object and Query Mode Settings.
Oct-27-2023 NA Added subsection, Create a database user.
Oct-03-2023 NA Updated sections:
- Specify PostgreSQL Connection Settings to describe the schema name displayed in Table and Custom SQL ingestion modes,
- Source Considerations to add information about logical replication not supported on read replicas, and
- Limitations to add limitations about data replicated by Hevo.
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 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 PostgreSQL Connection Settings to mention about SEE MORE in the Select an Ingestion Mode section.
Dec-19-2022 2.04 Updated section, Specify PostgreSQL Connection Settings to add information that you must specify all fields to create a Pipeline.
Dec-07-2022 2.03 Updated section, Specify PostgreSQL Connection Settings to mention about including skipped objects post-Pipeline creation.
Dec-07-2022 2.03 Updated section, Specify PostgreSQL Connection Settings to mention about the connectivity checker.
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, Update the client authentication file.
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.
Jun-14-2021 1.65 Updated the Grant Privileges to the User section to include latest commands.

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