# groonga - An open-source fulltext search engine and column store.

- 日本語

# 7.1.1. `grndb`

## 7.1.1.1. Summary

New in version 4.0.9.

`grndb` manages a Groonga database.

Here are features:

> - Checks whether database is broken or not.
> - Recovers broken database automatically if the database is recoverable.

## 7.1.1.2. Syntax

`grndb` requires command and database path:

    grndb COMMAND [OPTIONS] DATABASE_PATH

Here are available commands:

> - `check` - Checks whether database is broken or not.
> - `recover` - Recovers database.

## 7.1.1.3. Usage

Here is an example to check the database at `/var/lib/groonga/db/db`:

    % grndb check /var/lib/groonga/db/db

Here is an example to recover the database at `/var/lib/groonga/db/db`:

    % grndb recover /var/lib/groonga/db/db

## 7.1.1.4. Commands

This section describes available commands.

### 7.1.1.4.1. `check`

It checks an existing Groonga database. If the database is broken, `grndb` reports reasons and exits with non-`0` exit status.

Note

You must not use this command for opened database. If the database is opened, this command may report wrong result.

`check` has some options.

#### 7.1.1.4.1.1. `--target`

New in version 5.1.2.

It specifies a check target object.

If your database is large and you know an unreliable object, this option will help you. `check` need more time for large database. You can reduce check time by `--target` option to reduce check target.

The check target is checked recursive. Because related objects of unreliable object will be unreliable.

If the check target is a table, all columns of the table are also checked recursive.

If the check target is a table and its key type is another table, the another table is also checked recursive.

If the check target is a column and its value type is a table, the table is also checked recursive.

If the check target is an index column, the table specified as value type and all sources are also checked recursive.

Here is an example that checks only `Entries` table and its columns:

    % grndb check --target Entries /var/lib/groonga/db/db

Here is an example that checks only `Entries.name` column:

    % grndb check --target Entries.name /var/lib/groonga/db/db

### 7.1.1.4.2. `recover`

It recovers an existing broken Groonga database.

If the database is not broken, `grndb` does nothing and exits with `0` exit status.

If the database is broken and one or more index columns are only broken, `grndb` recovers these index columns and exists with `0` exit status. It may take a long time for large indexed data.

If the database is broken and tables or data columns are broken, `grndb` reports broken reasons and exits with non-`0` exit status. You can know whether the database is recoverable or not by `check` command.

Note

You must not use this command for opened database. If the database is opened, this command may break the database.