fbrescue FAQ

Can I get the data out of a Firebird database without the Firebird server?

Yes. fbrescue reads the .fdb file directly, without the engine and without fbclient, and exports every table to CSV, SQL (INSERT statements) or JSON Lines. It is a single binary for Windows, Linux and macOS. It also works when the database no longer opens and gbak cannot back it up. Step by step: open a .fdb file without Firebird.

Does fbrescue change or repair my database file?

No. It opens the file read-only and never writes to it; a test in CI runs every command on read-only copies of real databases and checks that nothing changed. fbrescue gets the data out into files you load into a new database; it does not repair the original. Still work on a copy: other tools you try may write to it.

Which Firebird versions does it support?

Firebird 2.5, 3.0, 4.0 and 5.0 (ODS 11.2 to 13.1), including Firebird 4 types (INT128, DECFLOAT, TIME and TIMESTAMP WITH TIME ZONE), BLOBs and multi-file databases. InterBase and Firebird 1.x, 2.0 and 2.1 are not supported.

Is it free?

Yes. fbrescue is open source under the MIT license: no license per database, no limit on the number of rows or databases.

Should I try gfix and gbak first?

Yes. On a copy of the file run gfix -v -full -n, then gfix -mend -full -ignore and gbak -b -ig -g. If the backup completes and restores, you get the whole database back, with indexes, triggers and procedures. Use fbrescue when gbak still stops.

How is fbrescue different from IBSurgeon FirstAID?

FirstAID is a commercial Windows tool that can repair the database file in place or extract data, and supports InterBase and older Firebird versions. fbrescue is free, read-only, runs on Windows, Linux and macOS, and only extracts data, from Firebird 2.5 to 5.0. See the comparison.

What does fbrescue not recover?

Indexes, triggers, stored procedures, views, users, generator values and constraints: it exports table definitions (schema.sql) and rows. Array columns are not exported yet. Rows on pages that are zeroed or cut off from the file are lost; every row it could not read is listed in _errors.jsonl.

Can it recover deleted or overwritten rows?

Often, if the old record versions are still on disk (not yet garbage-collected): --include-deleted writes deleted rows to a separate file, and --versions all writes every version of every row with its transaction and that transaction’s state.

What if the system tables are damaged?

Tables whose definitions are partly lost are exported as TABLE_<id> with columns FIELD_<n>. If the record formats themselves are lost, pass the CREATE TABLE statements of the database with --ddl schema.sql (the creation script, isql -x output, or an earlier fbrescue export), and fbrescue computes the record layout from them.

How much data does it recover?

It depends on the damage. On copies of a test database damaged in 13 different ways on Firebird 2.5 to 5.0, it recovers 100% of the rows when pointer, index, transaction inventory or header pages are zeroed, and everything but the damaged page’s rows when data pages are lost. The full table is in the README.

How can I get help without sending my data?

Run fbrescue report copy.fdb and attach the output to a GitHub issue. It describes the damage without any data, with table and column names replaced by numbers.

More: recovery steps, error messages, download.