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It is evident that the most appropriate approach for executing logical backup dumping and restoration is by leveraging the core PostgreSQL utilities, specifically pg_dump and pg_restore. Greenmask has been purposefully designed to align with PostgreSQL's native utilities, ensuring compatibility. Greenmask primarily handles data dumping operations independently and delegates the responsibilities of schema dumping and restoration to pg_dump and pg_restore respectively, maintaining seamless integration with PostgreSQL's standard tools.

Backup process

The process of backing up PostgreSQL databases is divided into three distinct sections:

  • Pre-data — this section encompasses the raw schema of tables, excluding primary keys (PK) and foreign keys (FK).
  • Data — the data section contains the actual table data in COPY format, including information about sequence current values and Large Objects data.
  • Post-data — in this section, you'll find the definitions of indexes, triggers, rules, and constraints (such as PK and FK).

Greenmask focuses exclusively on the data section during runtime. It delegates the handling of the pre-data and post-data sections to the core PostgreSQL utilities, pg_dump and pg_restore.

Greenmask employs the directory format of pg_dump and pg_restore. This format is particularly suitable for parallel execution and partial restoration, and it includes clear metadata files that aid in determining the backup and restoration steps. Greenmask has been optimized to work seamlessly with remote storage systems and obfuscation procedures.

When performing data dumping, Greenmask utilizes the COPY command in TEXT format, maintaining reliability and compatibility with the vanilla PostgreSQL utilities.

Additionally, Greenmask supports parallel execution, significantly reducing the time required for the dumping process.

Storage options

The core PostgreSQL utilities, pg_dump and pg_restore, traditionally operate with files in a directory format, offering no alternative methods. To meet modern backup requirements and provide flexible approaches, Greenmask introduces the concept of storages.

  • s3 — this option supports any S3-like storage system, including AWS S3, which makes it versatile and adaptable to various cloud-based storage solutions.
  • directory — this is the standard choice, representing the ordinary filesystem directory for local storage.


If you have suggestions for additional storage options that would be valuable to implement, feel free to share your ideas with us. Greenmask aims to accommodate a wide range of storage preferences to suit diverse backup needs.

Restoration process

In the restoration process, Greenmask combines the capabilities of different tools:

  • For schema restoration Greenmask utilizes pg_restore to restore the database schema. This ensures that the schema is accurately reconstructed.
  • For data restoration Greenmask independently applies the data using the COPY protocol. This allows Greenmask to handle the data efficiently, especially when working with various storage solutions. Greenmask is aware of the restoration metadata, which enables it to download only the necessary data. This feature is particularly useful for partial restoration scenarios, such as restoring a single table from a complete backup.

Greenmask also supports parallel restoration, which can significantly reduce the time required to complete the restoration process. This parallel execution enhances the efficiency of restoring large datasets.

Data obfuscation and validation

Greenmask works with COPY lines, collects schema metadata using the Golang driver, and employs this driver in the encoding and decoding process. The validate command offers a way to assess the impact on both schema (validation warnings) and data (transformation and displaying differences). This command allows you to validate the schema and data transformations, ensuring the desired outcomes during the obfuscation process.


If your table schema relies on functional dependencies between columns, you can address this challenge using the TemplateRecord transformer. This transformer enables you to define transformation logic for entire tables, offering type-safe operations when assigning new values.

Greenmask provides a framework for creating your custom transformers, which can be reused efficiently. These transformers can be seamlessly integrated without requiring recompilation, thanks to the PIPE (stdin/stdout) interaction.


Furthermore, Greenmask's architecture is designed to be highly extensible, making it possible to introduce other interaction protocols, such as HTTP or Socket, for conducting obfuscation procedures.

PostgreSQL version compatibility

Greenmask is compatible with PostgreSQL versions 11 and higher.