title: Painfully Slow Report coming from SSRS 2016
body: <p>I am in the process of moving a batch of reports (26) from SSRS 2014 to SSRS 2016. One of them is absolutely painfully slow, but only in a browser ( both IE and Chrome ). The report depends on a query within the report (not a stored proc). I can determine no significant difference between this reports and its sisters, which return results in 3-4 seconds regardless of browser. The time the query takes to run in SSMS is comparable to times to run similar queries in sister reports. Here are some details. SSMS Query • Execution Plan:</p>
  
  <p>• Returns 1124 Rows • Time Messages o SQL Server Execution Times:  CPU time = 15 ms, elapsed time = 261 ms. o SQL Server parse and compile time:  CPU time = 0 ms, elapsed time = 21 ms. o SQL Server Execution Times:  CPU time = 0 ms, elapsed time = 0 ms. Report Development Report Builder: • Runs well in 5 seconds or less. Visual Studio 2017: • Runs well in 7-10 seconds.   Browsers • Both IE and Chrome deliver results in about 9 minutes. Report Differences in the .rdl Files There are two obvious differences in the .xml files. SSRS 2016 1. DataSources and DataSets are defined at the top of the .xml 2.</p>
  
  <p>SSRS 1. DataSources and DataSets are defined starting at line 4678. 2.</p>
  
  <p>I have done about everything I can think of and have run out of ideas. Query language, .rdl files, and Execution Plan available on request.</p>