[Yandex Cloud documentation](../../index.md) > [Yandex Managed Service for YDB](../index.md) > [Step-by-step guides](index.md) > Managing tables and directories

# Managing tables and directories

This section describes how to manage row-oriented and document tables as well as directories using the cloud management console or [Terraform](../../tutorials/infrastructure-management/terraform-quickstart.md).

You can do the following:
* [Create a table](#create-table).
* [Change the table schema](#alter-table).
* [Delete a table](#drop-table).
* [Create and delete directories](#directories).

To work with tables and directories, you will need a [database](index.md).

## Creating a table {#create-table}

You can create a row-oriented table or a [document table](../concepts/dynamodb-tables.md).

### Row-oriented table {#create-ydb-table}

{% list tabs group=instructions %}

- Management console {#console}

  1. In the [management console](https://console.yandex.cloud), navigate to the folder page.
  1. Navigate to **Managed Service for YDB**.
  1. Select the database to create your table in.
  1. Navigate to the **Navigation** tab.
  1. Select **Create** → **Table** on the right side of the page.
  1. Configure the table:
     * Table **Name** must be unique within the database.
     * **Table type**: `Row table`.
  1. Add columns:
     * Column **Name** must be unique within the table.
     * Column data **Type**. Regardless of the data type, each column may contain a `NULL` value.
     * **Primary key**. Specify whether the column is part of the primary key. Primary indexes are automatically created based on the primary key.
  1. Set up [secondary indexes](https://ydb.tech/docs/en//concepts/secondary_indexes), if needed:
     * Secondary index **Name** must be unique within the table.
     * **Key**: One or more columns that make up a key for creating a secondary index.
  1. Configure the [partitioning](https://ydb.tech/docs/en//concepts/datamodel) policy:
     * `None`: The table is not partitioned.
     * `Evenly`: The entire range of values of Uint32 or Uint64 key columns (from 0 to the maximum value) is split into same-length partitions. When using this policy, set the number of partitions in the **Count** field.
     * `Explicitly`: Allows you to explicitly specify values for keys that will act as split points for initial table partitioning. To add another split point, click **Add split point**.
  1. Configure automatic partitioning:
     * **By size**: If enabled, a partition is split into two when it reaches a certain data size.
     * **By load**: If enabled, a partition is split into two if it receives high throughput (uses a lot of CPU time) for a certain period of time.
  1. Specify advanced table settings:
     * **Auto-partitioning by size in MB**: Data size threshold that triggers auto-partitioning by size.
     * **Minimum number of partitions**: Number of partitions in the table below which no partitions are merged by size or load.
     * **Maximum number of partitions**: Number of partitions in the table above which no partitions are split by size or load.
     * **Bloom filter for primary key**: If enabled, YDB uses a [Bloom filter](https://en.wikipedia.org/wiki/Bloom_filter) to search data by key. In some cases, it can speed up key reads.
  1. Click **Create table**.

  To create row-oriented tables, you can also use the [`CREATE TABLE`](https://ydb.tech/docs/en//yql/reference/syntax/create_table) command.


- Terraform {#tf}

   To learn how to create a row-oriented table using Terraform, see [Creating row-oriented and column-oriented tables in a database](../terraform/tables.md).

{% endlist %}

### Document table {#create-dynamodb-table}

{% list tabs group=instructions %}

- Management console {#console}

  {% note info %}

  Document tables are only available in Managed Service for YDB serverless mode.

  {% endnote %}

  1. In the [management console](https://console.yandex.cloud), navigate to the folder page.
  1. Navigate to **Managed Service for YDB**.
  1. Select the database to create your table in.
  1. Select **Create** → **Table** on the right side of the page.
  1. Configure the table:
     * Table **Name** must be unique within the database.
     * **Table type**: `Document table`.
  1. Add columns:
     * Column **Name** must be unique within the table.
     * Column data **Type**. Regardless of the data type, each column may contain a `NULL` value.
     * **Partition key**: Simple primary key that consists of one attribute. YDB uses a partition key as an input for internal hashing. The hashing function result determines the partition the element will be stored in.
     * **Sort key**. A primary key can be composite and consist of a partition key and a sort key. All elements sharing the partition key will be stored together and sorted according to their sort key value. In a document table that has both a partition key and a sort key, any two elements may share the partition key value but must have different sort key values.
  1. Click **Create table**.

- Terraform {#tf}

   You can learn how to create a document table using Terraform in [Creating document tables in a database](../terraform/dynamodb-tables.md).

{% endlist %}

### Column-oriented table {#create-column-table}

{% list tabs group=instructions %}

- Management console {#console}

  1. In the [management console](https://console.yandex.cloud), navigate to the folder page.
  1. Navigate to **Managed Service for YDB**.
  1. Select the database to create your table in.
  1. Navigate to the **Navigation** tab.
  1. Select **Create** → **Table** on the right side of the page.
  1. Configure the table:
     * Table **Name** must be unique within the database.
     * **Table type**: `Column table`.
  1. Add columns:
     * Column **Name** must be unique within the table.
     * Column data **Type**.
     * **Primary key**. Specify whether the column is part of the primary key. Primary indexes are automatically created based on the primary key.

        {% note info %}

        The column order in the primary key depends on the column order in the table you are creating.

        {% endnote %}

     * **NOT NULL constraint**. Specify whether the column may contain a `NULL` value.
     <!-- * **Default value**. Specify a default value for the column. -->
  1. Configure the table TTL parameters:
     * **Column**. Select the column whose value will be used to calculate the lifetime of rows.
     * **Lifetime**. Specify the lifetime of table rows.
     * **Unit**. Select the measurement unit for the table row lifetime you specified.
  1. Configure partitioning:
     * **Partition key**: Specify the column to split the table by.
     * **Partition count**: Specify the number of partitions for the table.
  1. Click **Create table**.

  To create column-oriented tables, you can also use the [`CREATE TABLE`](https://ydb.tech/docs/en//yql/reference/syntax/create_table) command.


- Terraform {#tf}

   You can learn how to create a column-oriented table using Terraform in [Creating row-oriented and column-oriented tables in a database](../terraform/tables.md).

{% endlist %}

## Changing the table schema {#alter-table}

### Row-oriented table {#alter-ydb-table}

{% list tabs group=instructions %}

- Management console {#console}

   In the YDB cloud console, you can add non-key columns to a table and change its automatic partitioning settings.

   1. In the [management console](https://console.yandex.cloud), navigate to the folder page.
   1. Navigate to **Managed Service for&nbsp;YDB**.
   1. Select the database to update a table in.
   1. Find the table in the list and select ![image](../../_assets/horizontal-ellipsis.svg) → **Edit**.
   1. Add new columns to the table and specify their parameters:
      * Column **Name** must be unique within the table.
      * Column data **Type**. Regardless of the data type, each column may contain a `NULL` value.
   1. To delete non-key columns from the table, click ![image](../../_assets/cross.svg) in the relevant row. You cannot delete columns that make up a primary key.
   1. Configure automatic partitioning:
      * **By size**: If enabled, a partition is split into two when it reaches a certain data size.
      * **By load**: If enabled, a partition is split into two if it receives high throughput (uses a lot of CPU time) for a certain period of time.
   1. Specify advanced table settings:
      * **Auto-partitioning by size in MB**: Data size threshold that triggers auto-partitioning by size.
      * **Minimum number of partitions**: Number of partitions in the table below which no partitions are merged by size or load.
      * **Maximum number of partitions**: Number of partitions in the table above which no partitions are split by size or load.
      * **Bloom filter for primary key**: If enabled, YDB uses a [Bloom filter](https://en.wikipedia.org/wiki/Bloom_filter) to search data by key. In some cases, it can speed up key reads.
   1. Click **Alter table**.

- Terraform {#tf}

   Learn more about the table entities you can change using Terraform in [Creating row-oriented and column-oriented tables in a database](../terraform/tables.md).

{% endlist %}

### Document table {#alter-dynamodb-table}

{% list tabs group=instructions %}

- Management console {#console}

   {% note info %}

   Currently, you can only add new rows to a table, without any preview in the management console.

   {% endnote %}

   1. In the [management console](https://console.yandex.cloud), navigate to the folder page.
   1. Navigate to **Managed Service for&nbsp;YDB**.
   1. Select the database to update a table in.
   1. Find the table in the list and click it.
   1. Click **Add row**.
   1. Enter the values for the columns listed in the form, then click **Add**.

- Terraform {#tf}

   Learn more about the table entities you can change using Terraform in [Creating document tables in a database](../terraform/dynamodb-tables.md).

{% endlist %}

To edit row-oriented tables, you can also use the [`ALTER TABLE`](https://ydb.tech/docs/en//yql/reference/syntax/alter_table) command.

### Column-oriented table {#alter-column-table}

{% list tabs group=instructions %}

- Management console {#console}

   1. In the [management console](https://console.yandex.cloud), navigate to the folder page.
   1. Navigate to **Managed Service for&nbsp;YDB**.
   1. Select the database to update a table in.
   1. Find the table in the list and select ![image](../../_assets/horizontal-ellipsis.svg) → **Edit**.

        Update the table schema as needed. You can do the following:

        -  Add new columns to the table and specify their parameters:
            * Column **Name** must be unique within the table.
            * Column data **Type**. Regardless of the data type, each column may contain a `NULL` value.
        -  To delete non-key columns from the table, click ![image](../../_assets/cross.svg) in the relevant row. You cannot delete columns that make up a primary key.
        -  Configure the table TTL parameters:
            * **Column**. Select the column whose value will be used to calculate the lifetime of rows.
            * **Lifetime**. Specify the lifetime of table rows.
            * **Unit**. Select the measurement unit for the table row lifetime you specified.

   1. Click **Alter table**.

  To update column-oriented tables, you can also use the [`ALTER TABLE`](https://ydb.tech/docs/en//yql/reference/syntax/alter_table) command.


- Terraform {#tf}

   Learn more about the table entities you can change using Terraform in [Creating row-oriented and column-oriented tables in a database](../terraform/tables.md).

   {% note info %}

   Updating the `store` and `partition_by` parameters of the column-oriented table will result in recreating the table.

   {% endnote %}

{% endlist %}

## Deleting a table {#drop-table}

### Row-oriented table {#drop-ydb-table}

{% list tabs group=instructions %}

- Management console {#console}

   1. In the [management console](https://console.yandex.cloud), navigate to the folder page.
   1. Navigate to **Managed Service for&nbsp;YDB**.
   1. Select the database to delete your table from.
   1. Find the table in the list and select ![image](../../_assets/horizontal-ellipsis.svg) → **Delete**.
   1. Confirm the deletion.

- Terraform {#tf}

   To delete a row-oriented table, delete the `yandex_ydb_table` resource.

{% endlist %}

### Document table {#drop-dynamodb-table}

{% list tabs group=instructions %}

- Management console {#console}

   1. In the [management console](https://console.yandex.cloud), navigate to the folder page.
   1. Navigate to **Managed Service for&nbsp;YDB**.
   1. Navigate to the database to delete your document table from.
   1. Select the document table from the list, then click ![image](../../_assets/horizontal-ellipsis.svg) → **Delete**.
   1. Confirm the deletion.

- Terraform {#tf}

   To delete a document table, delete the `aws_dynamodb_table` resource.

{% endlist %}

### Column-oriented table {#drop-ydb-column-table}

{% list tabs group=instructions %}

- Management console {#console}

   1. In the [management console](https://console.yandex.cloud), navigate to the folder page.
   1. Navigate to **Managed Service for&nbsp;YDB**.
   1. Select the database to delete your table from.
   1. Find the table in the list and select ![image](../../_assets/horizontal-ellipsis.svg) → **Delete**.
   1. Confirm the deletion.

- Terraform {#tf}

   To delete a column-oriented table, delete the `yandex_ydb_table` resource.

{% endlist %}

To delete tables, you can also use the [`DROP TABLE`](https://ydb.tech/docs/en//yql/reference/syntax/drop_table) command.

## Creating and deleting directories {#directories}

{% list tabs group=instructions %}

- Management console {#console}

  1. In the [management console](https://console.yandex.cloud), navigate to the folder page.
  1. Navigate to **Managed Service for&nbsp;YDB**.
  1. Select the database to create a directory in.
  1. Select **Create** → **Directory** on the right side of the page.
  1. Enter a name for your directory and click **Create directory**.

{% endlist %}