> ## Documentation Index
> Fetch the complete documentation index at: https://pearsdb.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Collection Structure

## General Structure

On start-up, the MindsDB project consists of 2 collections: `models` and `models_versions`.

You can verify it by running the following MQL commands:

1. First, switch to the `mindsdb` project.

   ```bash theme={null}
   > use mindsdb
   < 'switched to db mindsdb'
   ```

   <Tip>
     Here is the [doc page on the `PROJECT` entity](/sql/project) to learn more.
   </Tip>

2. Then, query for the available collections.

   ```bash theme={null}
   > show collections
   < models
     models_versions
   ```

## The `models` Collection

The `models` collection stores information about the models, such as name, status, accuracy, and more.

```bash theme={null}
> db.models.find({})
< {
    NAME: 'home_rentals_model',
    ENGINE: 'lightwood',
    PROJECT: 'mindsdb',
    VERSION: 1,
    STATUS: 'complete',
    ACCURACY: 1,
    PREDICT: 'rental_price',
    UPDATE_STATUS: 'up_to_date',
    MINDSDB_VERSION: '23.2.4.0',
    ERROR: null,
    SELECT_DATA_QUERY: 'db.home_rentals.find({})',
    TRAINING_OPTIONS: "{'target': 'rental_price', 'using': {}}",
    TAG: null,
    CREATED_AT: 2023-02-24T16:05:43.248Z,
    _id: ObjectId("000000000000007725907968")
  }
```

Where:

| Name                | Description                                                                     |
| ------------------- | ------------------------------------------------------------------------------- |
| `NAME`              | The name of the model.                                                          |
| `ENGINE`            | The engine used to create the model.                                            |
| `PROJECT`           | The project where the model resides.                                            |
| `VERSION`           | The version of the model.                                                       |
| `STATUS`            | Training status (`generating`, or `training`, or `complete`, or `error`).       |
| `ACCURACY`          | The model accuracy (`0.999` is a sample accuracy value).                        |
| `PREDICT`           | The name of the target column to be predicted.                                  |
| `UPDATE_STATUS`     | Training update status (`up_to_date`, or `updating`, or `available`).           |
| `MINDSDB_VERSION`   | The MindsDB version used while training (`22.8.2.1` is a sample version value). |
| `ERROR`             | Error message stores a value in case of an error, otherwise, it is null.        |
| `SELECT_DATA_QUERY` | It is a query that selects input data.                                          |
| `TRAINING_OPTIONS`  | Additional training parameters.                                                 |
| `TAG`               | The models can have tags to classify them into categories.                      |

Check out [this doc page](/sql/project#working-with-models) to learn how to create, view, and drop models.

## The `models_versions` Collection

The `models_versions` collection stores information about all present and past versions of each model.

<Tip>
  To learn more about managing models' versions, follow our [docs here](/sql/api/manage-models-versions).
</Tip>

```bash theme={null}
> db.models_versions.find({})
< {
    NAME: 'home_rentals_model',
    ENGINE: 'lightwood',
    PROJECT: 'mindsdb',
    ACTIVE: true,
    VERSION: 1,
    STATUS: 'complete',
    ACCURACY: 1,
    PREDICT: 'rental_price',
    UPDATE_STATUS: 'up_to_date',
    MINDSDB_VERSION: '23.2.4.0',
    ERROR: null,
    SELECT_DATA_QUERY: 'db.home_rentals.find({})',
    TRAINING_OPTIONS: "{'target': 'rental_price', 'using': {}}",
    TAG: null,
    CREATED_AT: 2023-02-24T16:05:43.248Z,
    _id: ObjectId("000000000000007725907969")
  }
```

Where:

| Name                | Description                                                                                         |
| ------------------- | --------------------------------------------------------------------------------------------------- |
| `NAME`              | The name of the model.                                                                              |
| `ENGINE`            | The engine used to create the model.                                                                |
| `PROJECT`           | The project where the model resides.                                                                |
| `ACTIVE`            | The status of the model's version. The value of `true` if active, the value fo `false` if inactive. |
| `VERSION`           | The version of the model.                                                                           |
| `STATUS`            | Training status (`generating`, or `training`, or `complete`, or `error`).                           |
| `ACCURACY`          | The model accuracy (`0.999` is a sample accuracy value).                                            |
| `PREDICT`           | The name of the target column to be predicted.                                                      |
| `UPDATE_STATUS`     | Training update status (`up_to_date`, or `updating`, or `available`).                               |
| `MINDSDB_VERSION`   | The MindsDB version used while training (`22.8.2.1` is a sample version value).                     |
| `ERROR`             | Error message stores a value in case of an error, otherwise, it is null.                            |
| `SELECT_DATA_QUERY` | It is a query that selects input data.                                                              |
| `TRAINING_OPTIONS`  | Additional training parameters.                                                                     |
| `TAG`               | The models can have tags to classify them into categories.                                          |

Check out [this doc page](/sql/project#working-with-models-version) to learn how to work with models' versions.

<Tip>
  To view all databases/projects, use the command below.

  ```bash theme={null}
  > show databases
  < admin               64.00 KiB
    information_schema  64.00 KiB
    mindsdb             64.00 KiB
    files               64.00 KiB
    mongo_demo_db       64.00 KiB
  ```

  Please note that `mindsdb` is the default project. Here is the [doc page on the `PROJECT` entity](/sql/project) to learn more.
</Tip>

<Tip>
  Please follow the [MindsDB Information Schema doc page](/sql/table-structure) to learn more.
</Tip>