Uploaded image for project: 'Documentation'
  1. Documentation
  2. DOCS-417

Add doc for option to disable index prefetching

      Config option for indexPrefetch commandline flag:

      Command line flag --replIndexPrefetch
      Parameter replIndexPrefetch
      values: none, _id_only, all
      "all" is the default if unspecified.

      New parameter replIndexPrefetch.
      Settable via the command line or use setParameter() command on a running server.
      Only valid on a server started with --replSet parameter.
      This allows a user to disable the prefetching of all index pages prior to the application
      of a replicated op on a secondary.
      For most use cases, prefetching all indexes for a given op will provide good performance.
      For use cases that do many in-place updates to documents in a collection with many indexes
      that are unaffected by such updates, using the '_id_only' setting may provide better performance
      than the 'all' setting. The '_id_only' setting only prefetches index pages for the _id index,
      which will always be used to find the document needed to be updated.
      The 'none' setting will be used for debugging only; there should be no production use cases for
      this setting.
      getParameter() supports getting the current value of this parameter.

            sam.kleinman Sam Kleinman (Inactive)
            andrew.leung@10gen.com Andrew Leung (Inactive)
            0 Vote for this issue
            0 Start watching this issue

              11 years, 40 weeks, 2 days ago