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Buffer Pool Extension With Multiple Files RRS feed

  • Question

  • So I support a Dynamics CRM environment where we have deployed Buffer Pool Extension to expand the buffer pool size for clean pages. This works okay in theory except that I am getting long query times with waits for "EC". Looking around this seems to relate to buffer pool extension waits. I am concerned that while expanding the available buffer pool I have introduced another bottleneck with the BPE.

    Looking at the output from querying sys.dm_os_buffer_pool_extension_configuration one of the columns is file_id. To me this would indicate that BPE possibly supports multiple files, like with other database files. Does anyone have any experience with this? All documentation and examples I have seen online only show a single file. I would be interested to see if my current issues could be mitigated with adding multiple files, I just need a way to try it to be able to test.


    Joie Andrew "Since 1982"


    • Edited by Joie Andrew Wednesday, November 13, 2019 4:40 PM
    Wednesday, November 13, 2019 4:37 PM

All replies

  • The documented syntax shows only a single BPE file is currently supported. The current actual file_id value is zero, which suggests multi-file support is not implemented but there may be hooks to facilitate implementing such a feature in the future should Microsoft choose to go there. 

    What is your ratio of BPE size to max memory? Is the BPE file on local SSD PCIe NVMe storage?

     


    Dan Guzman, Data Platform MVP, http://www.dbdelta.com

    Thursday, November 14, 2019 11:29 AM