title: Unusually slow Azure table storage query?
body: <p>I have a dotnet app running in Azure App Services and the Application Map in App Insights shows one noticeably slow connection:</p>
  
  <ul>
  <li>393 calls to Redis av. 4.1ms</li>
  <li>146 calls to readonly SQL server av. 11.6ms</li>
  <li>102 calls to writable SQL server av. 24.2ms</li>
  <li>17 calls to blob storage av. 98ms (mostly PUT of a 300Kish file)</li>
  <li>31 calls to AWS Simple Email Service av. 185ms (external and known slow!)</li>
  <li><strong>42 calls to table storage av. 130ms</strong></li>
  </ul>
  
  <p>The calls to table storage are divided into two queries, one that takes av. 100ms and one that takes average 160ms. The slower one simply calls <code>FetchAllAsync</code> e.g. no filter, on a table that has about 10 rows, each of which is very small.</p>
  
  <p>Since the system is showing some pretty impressive latencies on other services, why would table storage be so slow relatively? Is <code>FetchAllAsync</code> slow? Other comments show latencies of 20-30ms so I don't think I am being too strict?</p>
  
  <p>The C# code is simply <code>var results = await azureService.FetchAllAsync&lt;ImageWrapper&gt;("Images");</code> but this is image metadata, not images themselves.</p>