---
title: "Define primary index of data set"
slug: "define-primary-index-of-data-set"
tags: ["Task", "Data Modeling Studio", "DMS"]
updated: 2026-03-20T11:27:19Z
published: 2026-03-20T17:44:45Z
canonical: "docs.staedean.com/define-primary-index-of-data-set"
---

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

# Define primary index of data set

The standard table index for D365 F&SCM tables, as used by Data Modeling Studio, consists of these fields: **RecId** and **RecVersion**. You can select additional primary indexes, if available for the data set table. These additional primary indexes are then used as well by Data Modeling Studio.

> [!NOTE]
> **Note**
> 
> To use additional indexes, the table system fields must be added as well. If you select an additional index and the '**Add system fields**' field was set to '**No**', this field is automatically set to '**Yes**'.

### Steps

1. Go to **Data modeling studio** > **Data modeling studio** > **Data sets**.
2. In the list, click the link of the desired data set.
3. On the **Action Pane**, click **Create**.
4. Click **Index**.
5. On the dialog, all indexes, as defined for the data set table, are shown.

In the list, find the index that you want to use for the data set.
6. For each index that you want to use, select the '**Selected**' check box.
7. Click **OK**.
8. An index consists of one or more fields. To use an index, you must add the index fields to the data set. If you select an index, and the index field is not added to the data set, you get a message to add the index field to the data set.

Click **Yes**.

## Related

- [Set up data sets](/set-up-data-sets.md)