Open Document Database

OpenDocument Database (ODB) is an open, vendor-neutral database document format, standardized as part of ISO/IEC 26300 (the OASIS OpenDocument Format). It's the database member of the OpenDocument family alongside Open Document Text, Open Document Spreadsheet, Open Document Presentation, Open Document Graphics, and Open Document Formula — and the closest OpenDocument counterpart to Microsoft Access's .accdb/.mdb.

Two very different things an .odb file can be

This is the most important thing to know about .odb, and the one place it departs sharply from its sibling formats: an .odb file doesn't always contain the actual data.

• Embedded database — the file bundles a real database engine and its data inside the package. LibreOffice Base's default embedded engine switched from HSQLDB (a Java-based engine) to Firebird starting around LibreOffice 7.1, largely to drop the Java runtime dependency and move to a more actively maintained engine; either way, the actual tables live inside the .odb ZIP.
• Connection-only document — the file stores forms, reports, queries, and connection settings (via JDBC/ODBC) pointing at an external database (MySQL, PostgreSQL, another server), but holds none of the actual data itself. Opening the file without access to that external database gets you the UI, not the rows.

Package structure

Like every OpenDocument format, .odb is a ZIP archive:

• mimetype — a plain-text file holding the string application/vnd.oasis.opendocument.database; it must be the first entry in the ZIP and stored uncompressed.
• content.xml — forms, reports, and query definitions.
• settings.xml and database/ — connection configuration and, for an embedded database, the actual engine files.
• META-INF/manifest.xml — an index of every file in the package and its media type.

Software compatibility

| Category | Software | | --- | --- | | Native/open-source | LibreOffice Base (its default format), Apache OpenOffice Base | | Cloud-based | No direct Google Workspace equivalent — there's no mainstream cloud desktop-database app comparable to Base/Access | | Commercial | Microsoft Access doesn't natively open .odb, unlike PowerPoint/Word/Excel's direct ODF support; interoperability means exporting tables (e.g. to CSV or via SQL) rather than opening the file directly |

Common pitfalls

• Assuming an .odb file always contains the data — a connection-only file is just forms/reports/settings; losing access to the external database it points at makes the file effectively empty, even though it opens fine.
• Expecting Access-level drop-in compatibility — unlike the odt/ods/odp trio, there's no major commercial suite offering direct .odb support, so migrating between Base and Access means exporting and rebuilding, not just reopening the file.
• Forgetting the embedded engine matters for portability — an embedded HSQLDB-based .odb (older files) and a Firebird-based one (current default) aren't interchangeable at the engine level, even though both are valid .odb files; this rarely matters for normal use but can surprise anyone inspecting the package's internals.

Learn more

• ISO/IEC 26300 — the international standard defining OpenDocument Format.
• SQL for the query language used against the databases .odb files connect to or embed.
• Open Document Text, Open Document Spreadsheet, Open Document Presentation, Open Document Graphics, Open Document Formula for the other members of the OpenDocument family.