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Database Autonomy Service:Missing index

Last Updated:Mar 30, 2026

Missing indexes cause more than 90% of performance issues in ApsaraDB RDS for SQL Server instances, including high CPU utilization, high IOPS, slow queries, and request timeouts. Database Autonomy Service (DAS) detects these missing indexes and generates CREATE INDEX scripts so you can apply them during off-peak hours.

Limitations

SQL Server 2008 R2 instances running on standard SSDs or enhanced SSDs (ESSDs) are not supported.

View missing indexes

  1. Log on to the DAS console.

  2. In the left-side navigation pane, click Instance Monitoring.

  3. Find the instance you want to manage and click its instance ID.

  4. In the left-side navigation pane, choose Performance Optimization > Missing Indexes.

The Missing Indexes page has three sections:

Missing Index Overview

Provides an overview of missing index statistics for the instance.

  • To refresh the statistics, click Recollect, then click OK. After a few minutes, refresh the page to see the updated index usage statistics.

  • To save the overview as a file, click Save as PDF File.

Charts of Missing Index Information

Displays the trend of missing indexes over time.

Missing Index Details

Lists all detected missing indexes.

Action Description
Custom Search Set filter conditions to query specific missing index information.
Export Script Set filter conditions and export the CREATE INDEX statements for the missing indexes.
Export File Set filter conditions and export the missing index data to an Excel, CVS, or TXT file.