# Translation Memory

Pootle provides matching translations to the current string. Translator can use these matches as their translation or to aid their translation.

Matches are based on previous translations of similar strings. These Translation Memory (TM) matches mean that you can speed up your translation and ensure consistency across your work.

## Using Translation Memory

Translation Memory matches are automatically retrieved when you enter a new translation unit. These are displayed below the editing widget. You can insert a TM match by clicking on a match row.

The differences between the current string and the match are highlighted, this allows you to see how the two differ and helps you make changes to the match to adapt it for use with the current string.

## Configuring Translation Memory

Translation Memory will work out of the box with a default Pootle installation. There are three methods of getting Translation Memory.

1. Amagama - for remote Translation Memory
2. Elasticsearch - for local Translation Memory
3. Elasticsearch - for external Translation Memory

### Amagama based remote TM

By default Pootle will query Translate’s Amagama Translation Memory server, which hosts translations of an extensive collection of Opensource software.

If you want to setup and connect to your own TM server then the `AMAGAMA_URL` will allow you to point to a private TM server.

To disable Amagama set `AMAGAMA_URL` to `''`.

### Elasticsearch-based TMs

New in version 2.7.

Pootle can also retrieve TM matches stored on Elasticsearch-based TM servers. These TM servers require Elasticsearch to be installed and running.

Note

Elasticsearch depends on Java. Note that some systems may ship with OpenJDK, however elasticsearch recommends using Oracle JDK.

Install the required Python libraries:

    (env) $ pip install --process-dependency-links Pootle[es5]

Note

Elasticsearch TM should work with any version of Elasticsearch, our tests run against Elasticsearch 5.x. For support for Elasticsearch 1.x and Elasticsearch 2.x, simply replace es5 with es1 and es2 respectively in the above command.

Pootle supports two types of Elasticsearch-based TMs:

- Local TM: (just one, named `local`) is populated using translations stored in Pootle database and every new translation gets automatically imported to it.
- External TMs: (several) are populated from translation files specifically provided by the server admins, and are not automatically updated.

Both local and external TM settings can be adjusted in `POOTLE_TM_SERVER`. A configuration example for local and external TM can be found in the default `~/.pootle/pootle.conf`, and can be enabled by uncommenting the example.

Please see the `POOTLE_TM_SERVER-WEIGHT` for a full example of the configuration necessary to set up local/external TM.

Both Amagama and Elasticsearch based TMs can operate together. Though you may want to disable Amagama.

#### Elasticsearch-based local TM

New in version 2.7.

To use it, the `local` TM must be enabled in `POOTLE_TM_SERVER` and will need to be populated using the `update_tmserver` command:

    (env) $ pootle update_tmserver

Once populated Pootle will keep Local TM up-to-date.

#### Elasticsearch-based external TMs

New in version 2.7.3.

In order to use them they must be enabled in `POOTLE_TM_SERVER` and you will need to populate them using the `update_tmserver` command specifying the TM to use with `--tm` and the display name with `--display-name`:

    (env) $ pootle update_tmserver --tm=external --display-name=Pidgin af.po gl.tmx

A display name is a label used to group translations within a TM. A given TM can host translations for several labels. Just specify them with `--display-name`:

    (env) $ pootle update_tmserver --tm=external --display-name=GNOME pt.tmx eu.po xh.po

It is possible to have several Elasticsearch-based external TM servers working at once, along with the Elasticsearch-based local TM server. In order to do so just add new entries to `POOTLE_TM_SERVER`:

    POOTLE_TM_SERVER = {

        ...

        'libreoffice': {
            'ENGINE': 'pootle.core.search.backends.ElasticSearchBackend',
            'HOST': 'localhost',
            'PORT': 9200,
            'INDEX_NAME': 'whatever',
            'WEIGHT': 0.9,
            'MIN_SCORE': 'AUTO',
        },
    }

Make sure `INDEX_NAME` is unique. You might also want to tweak `WEIGHT` to change the score of the TM results in relation to other TM servers (valid values are between `0.0` and `1.0`).

To use these additional external TMs you will need to populate them using the `update_tmserver` command specifying the TM server with `--tm`:

    (env) $ pootle update_tmserver --tm=libreoffice --display-name=LibreOffice af.po gl.tmx

Check `update_tmserver` for more options.

Note that Pootle will not push new translations to these TM servers unless you explicitly use the `update_tmserver` command, giving you full control of which translations make into them.