Merge pull request #259770 from guywi-ms/custom-table-updates

Create-custom-table.md updates and clarifications

Author: prmerger-automator[bot]

articles/azure-monitor/logs/create-custom-table.md

@@ -8,13 +8,16 @@ ms.service: azure-monitor
 ms.custom: devx-track-azurepowershell
 ms.topic: how-to 
 ms.date: 10/23/2023
-# Customer intent: As a Log Analytics workspace administrator, I want to create a table with a custom schema to store logs from an Azure or non-Azure data source.
+# Customer intent: As a Log Analytics workspace administrator, I want to manage table schemas and be able create a table with a custom schema to store logs from an Azure or non-Azure data source.
 ---
 
 # Add or delete tables and columns in Azure Monitor Logs
 
 [Data collection rules](../essentials/data-collection-rule-overview.md) let you [filter and transform log data](../essentials/data-collection-transformations.md) before sending the data to an [Azure table or a custom table](../logs/manage-logs-tables.md#table-type-and-schema). This article explains how to create custom tables and add custom columns to tables in your Log Analytics workspace.  
 
+> [!IMPORTANT]
+> Whenever you update a table schema, be sure to [update any data collection rules](../essentials/data-collection-rule-overview.md) that send data to the table. The table schema you define in your data collection rule determines how Azure Monitor streams data to the destination table. Azure Monitor does not update data collection rules automatically when you make table schema changes.  
+
 ## Prerequisites
 
 To create a custom table, you need:
@@ -49,6 +52,9 @@ To create a custom table, you need:
 
 Azure tables have predefined schemas. To store log data in a different schema, use data collection rules to define how to collect, transform, and send the data to a custom table in your Log Analytics workspace.
 
+> [!IMPORTANT]
+> Custom tables have a suffix of **_CL**; for example, *tablename_CL*. The Azure portal adds the **_CL** suffix to the table name automatically. When you create a custom table using a different method, you need to add the **_CL** suffix yourself. The *tablename_CL* in the [DataFlows Streams](../essentials/data-collection-rule-structure.md#dataflows) properties in your data collection rules must match the *tablename_CL* name in the Log Analytics workspace.
+
 > [!NOTE]
 > For information about creating a custom table for logs you ingest with the deprecated Log Analytics agent, also known as MMA or OMS, see [Collect text logs with the Log Analytics agent](../agents/data-sources-custom-logs.md#define-a-custom-log-table).
 
@@ -111,9 +117,6 @@ To create a custom table, run the [az monitor log-analytics workspace table crea
 
 Use the [Tables - Update PATCH API](/rest/api/loganalytics/tables/update) to create a custom table with the PowerShell code below. This code creates a table called *MyTable_CL* with two columns. Modify this schema to collect a different table. 
 
-> [!IMPORTANT]
-> Custom tables have a suffix of *_CL*; for example, *tablename_CL*. The *tablename_CL* in the DataFlows Streams must match the *tablename_CL* name in the Log Analytics workspace.
-
 1. Select the **Cloud Shell** button in the Azure portal and ensure the environment is set to **PowerShell**.
 
     :::image type="content" source="../logs/media/tutorial-workspace-transformations-api/open-cloud-shell.png" lightbox="../logs/media/tutorial-workspace-transformations-api/open-cloud-shell.png" alt-text="Screenshot of opening Cloud Shell in the Azure portal.":::