After careful consideration, we decided to end support for Amazon FinSpace, effective October 7, 2026. Amazon FinSpace will no longer accept new customers beginning October 7, 2025. As an existing customer with an Amazon FinSpace environment created before October 7, 2025, you can continue to use the service as normal. After October 7, 2026, you will no longer be able to use Amazon FinSpace. For more information, see [Amazon FinSpace end of support](https://docs.aws.amazon.com/finspace/latest/userguide/amazon-finspace-end-of-support.html). 

# Setting up for database maintenance
<a name="dbmaint-writable-database-dataviews"></a>

To perform the database maintenance operations, you need a writeable shallow copy of a database . A writable shallow copy of a kdb database only loads the metadata of your database files to make them visible on the file system and loads the actual file content as they are accessed. To optimise time and memory utilization, it is recommended not to load file content initially, as not all files may be necessary for a database maintenance operation. For instance, in the case of renaming a table, no files are read or updated directly. 

To create a writeable shallow copy of database, you can create dataviews with read write property set as true and enable on-demand caching in the configuration. A dataview performs minimal loading of files on the file system as needed by a database maintenance operation when on-demand caching is enabled. Reading an existing database file for the first time is slower as compared to accessing the files that have been previously read or newly written. This is because files are loaded onto the file system as they are accessed in case of on-demand caching.

## Creating writeable dataviews by using console
<a name="dbmaint-writable-database-dataviews-console"></a>

Before you proceed, complete the following prerequisites:
+ Create a kdb environment. For more information, see [Creating a kdb environment](using-kdb-environment.md#create-kdb-environment).
+ Create a kdb database. For more information, see [Creating a kdb database](using-kdb-db.md#create-kdb-db).
+ Create a new changeset. For more information, see [Creating a new changeset](using-kdb-db.md#kdb-db-changesets).
+ Create a kdb volume. Make sure this volume is not used by any other resource. For more information, see [Creating a Managed kdb volume](create-volumes.md).

**To create a writeable dataview**

1. Sign in to the AWS Management Console and open the Amazon FinSpace console at [https://console.aws.amazon.com/finspace](https://console.aws.amazon.com/finspace/landing).

1. In the left pane, under **Managed kdb Insights**, choose **Kdb environments**.

1. From the kdb environments table, choose the name of the environment.

1. On the environment details page, choose the **Databases** tab.

1. From the list of databases, choose a database name.

1. On database details page, choose the **Dataviews** tab.

1. Choose **Create dataview**.

1. On the **Create dataview** page, enter a unique name for the dataview.

1. (Optional) Enter a description for your dataview.

1. Choose the availability zone that you want to associate with the dataview. Currently, you can only choose single availability zone.

1. Under **Changeset update settings**, do the following.

   1. Choose **Static** mode of update. 
**Note**  
The **Read Write** option is only available for **Static** update mode as you cannot perform automatic updates on a writeable dataview.

   1. Select the **Changeset ID** for the changeset you created to indicate which version of data you want.

   1. Choose **Read Write** as **True** to make this dataview as writeable. You cannot change this later.

1. Add **Segment configuration**. 
**Note**  
The **Segment configuration** is required if **Read Write** is **True**.
You can only add one segment for a writeable dataview. 
The **Database path** is disabled and defaults to **\$1\$1** when **Read Write** is **True** as you cannot have partial writeable dataviews on cache.

   1. Choose a volume for caching. Use an exclusive volume for writable dataviews, it should not be in use by any other dataviews.

   1. For **On demand caching**, choose **True** to enable on demand caching on the selected database path when a particular file or a column of a database is accessed. When you enable on demand caching, files will only be copied to the dataview when they are accessed by code for reading or writing. When you disable on demand caching, everything is cached. The default value is **False**. 

1. Choose **Create dataview**. The database details page opens and the table under **Dataviews** lists the newly created database along with its status.

## Creating writeable dataviews by using FinSpace API operations
<a name="dbmaint-writable-database-dataviews-api"></a>

Before you proceed, complete the following prerequisites:
+ Create a kdb environment by using the [CreateKxEnvironment](https://docs.aws.amazon.com/finspace/latest/management-api/API_CreateKxEnvironment.html) API operation.
+ Create a kdb database by using the [CreateKxDatabase](https://docs.aws.amazon.com/finspace/latest/management-api/API_CreateKxDatabase.html) API operation.
+ Create a new changeset by using the [CreateKxChangeset](https://docs.aws.amazon.com/finspace/latest/management-api/API_CreateKxChangeset.html) API operation.
+ Create a kdb volume by using the [CreateKxVolume](https://docs.aws.amazon.com/finspace/latest/management-api/API_CreateKxVolume.html) API operation. Make sure this volume is unique for this dataview and is not used by any other resource. 

To create a dataview with writable shallow copy of a database, create a dataview with the volume that has writable segments by using the [CreateKxDataview](https://docs.aws.amazon.com/finspace/latest/management-api/API_CreateKxDataview.html) API operation. You can make dataview as writeable by setting the `readWrite` parameter as true. You can only use this parameter for a static update mode. The `onDemand` parameter allows you to enable or disable on-demand caching on the selected dbPaths.

Sample `CreateKxDataview` API request

```
{
    "autoUpdate": false,
    "availabilityZoneId": "use1-az1",
    "clientToken": "65117136-4421-4371-0f1a-ce012823126",
    "changesetId": "latest_changesetId",
    "readWrite": true,
    "segmentConfigurations": [{
            "volumeName": "test_vol",
            "dbPaths": [
                "/*"
            ],
            "onDemand": true
        }

    ],
    "azMode": "SINGLE",
    "dataviewName": "test_dv"
}
```

Following are some of the considerations for the above request.
+ The `autoUpdate` must be `false` for if `readWrite` is `true` on the dataviews.
+ You need exclusive volume for creating a writable dataview. The volume mentioned in the `segmentConfiguration` should not be used by any other dataview.
+ The `dbPath` must be set as "/\$1" for writable dataview.
+ Only a single `segmentConfiguration` is allowed when `readWrite` is true. The `dbPaths` on the segment should be set as "\$1\$1" .
+ A dataview with `readWrite` set as `true` is not allowed to be updated.
+ You cannot update the `readWrite` property later.
+ A dataview can only have a single segment if `onDemand` is `true` on a segment.