From the left navigation, click **datasets**.
Find the dataset you would like to edit and click the name to be taken to the editor.
Search by tags or dataset name and narrow down by field or category. See Dataset overview.
Click **Run** to retrieve a sample of the data at any time.
You can update the dataset itself, or add fields. (You can't remove fields; contact your Customer Solutions Manager for assistance).
If you update the dataset, revalidate it before it can be saved (see Dataset Validation).
If you add new fields, configure them. (see Field Configuration).
You can also edit the dataset field description:
Once validation passes and any new dataset field is configured, click **Save** to commit your changes.
Dataset updates are reflected after the next run of your Simon pipe.
## For Identity-Providing Datasets
There are a couple of reasons why you’d want to edit an Identity-Providing Dataset.
You need to bring an additional identifier from the data source into Simon.
You need to remove an identifier from the dataset.
### Adding a new identifier
In order to add a new identifier to an existing Identity-Providing Dataset, the identifier must exist in the data source from which the dataset is pulling. Simply add a new row to the Identity-Providing Dataset SQL query for the new identifier.
If you’re adding an identifier that does not currently exist elsewhere in your account, speak to your account manager to ensure it’s available for use in the Identity-Providing Dataset you’re editing.
There are a couple things to keep in mind when attempting to add a new identifier to an existing Identity-Providing Dataset:
Because saving a new query version triggers a backfill with the new data, it may be more difficult to debug where an identifier came from in the future, and;
A backfill could cause a delay in the next pipe run depending on the number of contacts in your account and the size of the dataset.
### Removing an identifier
Because Identity-Providing Datasets are the bedrock of your customer table, it’s extremely risky to remove an identifier from an existing Identity-Providing Dataset. Removing an identifier will cause stale data to be present in your account. Please speak to your account manager if you need to remove an identifier from an existing Identity-Providing Dataset.