Manage large lists for performance (MOSS)

SharePoint Products and Technologies support large lists. However, you must carefully control how end-users view the lists to help prevent adverse effects on performance.

  • For best performance, do not exceed 2,000 items in a list level (for example, the root of the list or a single folder).
  • If you must create and browse large lists, use the following best practices:
  • Index the list on one or more columns.
  • Change the default view of the list to a customized filtered view that follows these recommendations
    • The view returns fewer than 5,000 items
    • The first column that you use to filter the view has an index and that it sufficiently reduces the total number of items returned.
    • The view displays only those columns that are absolutely required.
    • The view includes as few lookup columns as possible. Each lookup column in a list that is included in a view causes an additional join and additional calls to the database.
  • Evaluate list size with regard to the number of columns in a list. Lists with lots of columns can perform slowly.

Be aware that the following settings and operations can significantly affect the performance of a site that has large lists.

  • Complex explicit permissions (permissions on the list or library, folder, or item or document level) force authorization checking on each item.
  • Changing authorization settings.
  • Creating, updating, and deleting indexes.
  • Importing and exporting content.
  • Deleting a list.
  • Deploying new content types or updating existing content types.
  • If you have workflows that generate lots of task and history items, you might be creating large lists. For very active workflows, follow these practices:
  • Keep the AutoCleanupDays timer job running to clean up tasks on completed workflows older than 60 days.
  • When you create workflow associations, if you expect that a workflow will be heavily used or will create lots of task and history items, use non-default task and history lists.

Please be aware that if you have a site that uses large lists, it can slow down the performance of site collection backups performed with the Stsadm backup operations.

More info https://technet.microsoft.com/en-us/magazine/2009.08.insidesharepoint.aspx