Merge pull request #113408 from kevinvngo/patch-154

Updated two recommendations for Advisor

Author: American-Dipper

articles/synapse-analytics/sql-data-warehouse/sql-data-warehouse-concept-recommendations.md

@@ -7,7 +7,7 @@ manager: craigg-msft
 ms.service: synapse-analytics
 ms.topic: conceptual
 ms.subservice: 
-ms.date: 02/05/2020
+ms.date: 04/30/2020
 ms.author: kevin
 ms.reviewer: igorstan
 ms.custom: azure-synapse
@@ -19,7 +19,7 @@ This article describes the Synapse SQL recommendations served through Azure Advi
 
 SQL Analytics provides recommendations to ensure your data warehouse workload is consistently optimized for performance. Recommendations are tightly integrated with [Azure Advisor](../../advisor/advisor-performance-recommendations.md?toc=/azure/synapse-analytics/sql-data-warehouse/toc.json&bc=/azure/synapse-analytics/sql-data-warehouse/breadcrumb/toc.json) to provide you with best practices directly within the [Azure portal](https://aka.ms/Azureadvisor). SQL Analytics collects telemetry and surfaces recommendations for your active workload on a daily cadence. The supported  recommendation scenarios are outlined below along with how to apply recommended actions.
 
-You can [check your recommendations](https://aka.ms/Azureadvisor) today! Currently this feature is applicable to Gen2 data warehouses only.
+You can [check your recommendations](https://aka.ms/Azureadvisor) today! 
 
 ## Data skew
 
@@ -47,14 +47,22 @@ physical characteristics:
 
 Advisor continuously leverages workload-based heuristics such as table access frequency, rows returned on average, and thresholds around data warehouse size and activity to ensure high-quality recommendations are generated.
 
-The following describes workload-based heuristics you may find in the Azure portal for each replicated table recommendation:
+The following section describes workload-based heuristics you may find in the Azure portal for each replicated table recommendation:
 
 - Scan avg- the average percent of rows that were returned from the table for each table access over the past seven days
 - Frequent read, no update - indicates that the table has not been updated in the past seven days while showing access activity
 - Read/update ratio - the ratio of how frequent the table was accessed relative to when it gets updated over the past seven days
-- Activity - measures the usage based on access activity. This compares the table access activity relative to the average table access activity across the data warehouse over the past seven days.
+- Activity - measures the usage based on access activity. This activity compares the table access activity relative to the average table access activity across the data warehouse over the past seven days.
 
 Currently Advisor will only show at most four replicated table candidates at once with clustered columnstore indexes prioritizing the highest activity.
 
 > [!IMPORTANT]
-> The replicated table recommendation is not full proof and does not take into account data movement operations. We are working on adding this as a heuristic but in the meantime, you should always validate your workload after applying the recommendation. Please contact [email protected] if you discover replicated table recommendations that causes your workload to regress. To learn more about replicated tables, visit the following [documentation](design-guidance-for-replicated-tables.md#what-is-a-replicated-table).
+> The replicated table recommendation is not full proof and does not take into account data movement operations. We are working on adding this as a heuristic but in the meantime, you should always validate your workload after applying the recommendation. To learn more about replicated tables, visit the following [documentation](design-guidance-for-replicated-tables.md#what-is-a-replicated-table).
+
+
+## Adaptive (Gen2) cache utilization
+When you have a large working set, you can experience a low cache hit percentage and high cache utilization. For this scenario, you should scale up to increase cache capacity and rerun your workload. For more information visit the following [documentation](https://docs.microsoft.com/azure/synapse-analytics/sql-data-warehouse/sql-data-warehouse-how-to-monitor-cache). 
+
+## Tempdb contention
+
+Query performance can degrade when there is high tempdb contention.  Tempdb contention can occur via user-defined temporary tables or when there is a large amount of data movement. For this scenario, you can scale for more tempdb allocation and [configure resource classes and workload management](https://docs.microsoft.com/azure/synapse-analytics/sql-data-warehouse/sql-data-warehouse-workload-management) to provide more memory to your queries.