# Avoid a hidden merge dependency that stops a workbook's downstream result

> Will a hidden workbook merge step run when another merge step depends on it?

- Canonical URL: https://update.dsesecurity.com/updates/dse-20260909-244-avoid-a-hidden-merge-dependency-that-stops-a-workbook-s-downstream-result/
- Publisher: Detection Systems & Engineering (DSE Security)
- Author: DSE Security Editorial Team
- Published: 2026-09-10T00:27:52+00:00
- Modified: 2026-09-10T01:20:46+00:00
- Last reviewed by DSE: 2026-09-09
- Resource type: Guide
- DSE priority: Information
- Topics: IT
- Reading time: 2 minutes

## What you need to know

Will a hidden workbook merge step run when another merge step depends on it?

## Potentially affected

Azure Workbooks using a merge data source that references another hidden merge step.

## DSE recommendation

Flatten a chained merge where practical and test visibility-dependent execution before publishing the workbook.

## Article

## Source facts

Workbooks can run hidden query and metric steps when a merge references them, but hidden steps that themselves use the merge data source do not run. A downstream merge referencing such a hidden merge waits until that step becomes visible. Microsoft notes that one merge can combine several sources, so chaining merge steps is rarely necessary. [Microsoft Learn](https://learn.microsoft.com/en-us/azure/azure-monitor/visualize/workbooks-data-sources).

## Applicability

Use this execution check when a workbook result disappears after an author hides an intermediate step. Distinguish an ordinary hidden source query from a hidden merge; their treatment is not interchangeable.

## DSE recommendation

Flatten a chained merge where practical and test visibility-dependent execution before publishing the workbook. Sketch which source steps feed the final result and identify any intermediate merge that is hidden by default or by a parameter choice. Keep presentation cleanup separate from changes to the data dependency structure. Preserve the original workbook while revising the chain so expected results can be compared.

## Verification

Run the workbook with the intermediate merge visible and record the downstream result. Repeat with the intended hidden state and check whether the dependency still executes. After restructuring, compare the final rows and values with the known visible-step result across relevant parameter choices. Do not treat a newly empty final grid as evidence that the monitored environment has no matching data until this execution dependency has been excluded.

## Official references

[Microsoft Learn: Workbook data sources and merge behavior](https://learn.microsoft.com/en-us/azure/azure-monitor/visualize/workbooks-data-sources). Source reviewed September 9, 2026.

## Primary reference

- Name: Azure Workbooks data sources - Azure Monitor | Microsoft Learn
- Authority: Microsoft Learn
- URL: https://learn.microsoft.com/en-us/azure/azure-monitor/visualize/workbooks-data-sources
- Source publication date: Not stated by the source

## Citation and use

Preferred citation: “Avoid a hidden merge dependency that stops a workbook's downstream result,” DSE Security, https://update.dsesecurity.com/updates/dse-20260909-244-avoid-a-hidden-merge-dependency-that-stops-a-workbook-s-downstream-result/
Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/
Usage and citation policy: https://update.dsesecurity.com/usage/
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