---
name: "mdb_dump"
section: "1"
platform: "linux"
package: "lmdb"
version: "0.9.35-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/mdb_dump"
---

# mdb\_dump(1)

LMDB environment export tool

## NAME

mdb\_dump - LMDB environment export tool

## SYNOPSIS

**mdb\_dump** \[**-V**\] \[**-f** *file\]* \[**-l**\] \[**-n**\] \[**-p**\] \[**-a** \| **-s** *subdb\]*  **envpath**

## DESCRIPTION

The **mdb\_dump** utility reads a database and writes its contents to the standard output using a portable flat-text format understood by the [**mdb\_load**(1)](/mdb_load/1.md) utility.

## OPTIONS

- **-V**

  Write the library version number to the standard output, and exit.

- **-f** file

  Write to the specified file instead of to the standard output.

- **-l**

  List the databases stored in the environment. Just the names will be listed, no data will be output.

- **-n**

  Dump an LMDB database which does not use subdirectories.

- **-p**

  If characters in either the key or data items are printing characters (as defined by [isprint(3)](/isprint/3.md)), output them directly. This option permits users to use standard text editors and tools to modify the contents of databases.

  Note: different systems may have different notions about what characters are considered printing characters, and databases dumped in this manner may be less portable to external systems.

- **-a**

  Dump all of the subdatabases in the environment.

- **-s** subdb

  Dump a specific subdatabase. If no database is specified, only the main database is dumped.

## DIAGNOSTICS

Exit status is zero if no errors occur. Errors result in a non-zero exit status and a diagnostic message being written to standard error.

Dumping databases that use user-defined comparison functions will output records with the ordering imposed by those comparison functions. If **mdb\_load** is invoked without including the **-a** option when reloading those records, the new databases will likely be damaged beyond repair, permitting neither record storage nor retrieval.

## SEE ALSO

[**mdb\_load**(1)](/mdb_load/1.md)

## AUTHOR

Howard Chu of Symas Corporation \<http://www.symas.com\>