title: SQL server virtual memory usage and performance
body: <p>I have  a very large DB used mostly for analytics. The performance overall is very sluggish. I just noticed that when running the query below, the amount of virtual memory used greatly exceeds the amount of physical memory available. Currently, physical memory is 10GB (10238k bytes) whereas the virtual memory returns significantly more - 8388607k bytes. That seems really wrong, but I'm at a bit of a loss on how to proceed.</p>
  
  <pre><code>USE [master];
  GO
  select 
      cpu_count
  ,    hyperthread_ratio
  ,    physical_memory_in_bytes / 1048576 as 'mem_MB'
  ,    virtual_memory_in_bytes / 1048576 as 'virtual_mem_MB'
  ,    max_workers_count
  ,    os_error_mode
  ,    os_priority_class
  from 
      sys.dm_os_sys_info 
  </code></pre>