---
title: DataHub
slug: litmusedge/product-features/datahub
description: The DataHub module allows you to store data polled from the connected devices with data storage enabled. A variety of data formats are supported.
docTags: 
createdAt: 2022-03-30T21:10:59.000Z
---

The DataHub module allows you to store data polled from connected DeviceHub devices with data storage enabled. 

To store data, you must select the **Enable Data Store** option for the device you want to store data for. You have the option of storing data for a specific period to support analytics on the historic data in the **Retention Hours** field. See [Enable Data Store](docId\:pal6ABPZbrimdU9LvGJ30) to learn more. 

Litmus Edge stores the polled data in a NoSQL timeseries database.

:::hint{type="info"}
**Limitation**: When using DataHub for storing data polled from connected devices, it's important to note the following limitations:

- InfluxDB initialization for large databases takes a long time with high CPU utilization. Ensure the Litmus Edge device has sufficient computing resources.
- DataHub does not store custom-formatted driver output like JSON or arrays to ensure efficient NoSQL timeseries database handling.
- DataHub handles string values differently than integers. As a result, when querying stored data, the way string and integer values are handled can impact the structure and results of your query.
  Sample Influx Query:
  - **For String Values: **`SELECT "value_str" FROM "temperature_readings" WHERE ("value_str"::field = 'pressure') AND $timeFilter`
  - **For Integer Values:** `SELECT "value" FROM "temperature_readings" WHERE ("value"::field = 555) AND $timeFilter`
:::

You have the option of configuring an internal or external InfluxDB timeseries database. 

The DataHub has the following sub pages:

- **Configuration***: *Toggle the timeseries database, change source type, and perform additional customizations. 
- **DB Management**: Expand a database view to display your connected devices, remove specific data storage for a connected device, and delete the timeseries database.
- **DB Users**: Add and delete database users, reset a user's password, add privileges to a user, as well as view the user list.
- **Edge Cascading**: Configure Edge Cascading v2 to connect multiple Litmus Edge instances in hub-and-spoke or multi-tier configurations.

# Next Steps

- [Configure the Timeseries DB](docId\:HqkH8iNwjerydFcwBQPwt)
- [DB Management](docId:6Q04r99W1eamg_J3q_o48) 
- [DB Users](docId\:wLJ8WK_O5MHLTxwrip5lL)