SharePoint List View Lookup Threshold

With the release of SharePoint 2010, resource throttling was introduced at the web application level to limit the number of items a list view (database query) can process in a single request, as well as to limit the number of lookup columns a single view can utilize at one time.

By default, List View Lookup threshold is set to 8.

To view the settings page for

Central Admin -> Application Management -> Manage Web Applications -> Select the web application -> General Settings -> Resource Throttling

As per TechNet,

�Each lookup column in a list view causes a join with another table. Each additional lookup column in a view increases the complexity of metadata navigation and list view queries. In addition to standard lookup columns, single-value managed metadata, multiple-value managed metadata, single-value people and group columns, and multiple-value people and group columns count as lookup columns. Adding lookup columns to a view does not cause a gradual or linear decrease in performance, rather performance is somewhat stable until after eight columns when it rapidly degrades.�

In short, all the below column types are considered towards list view look up threshold:

- Standard lookup columns

- Single-value managed metadata columns

- Multiple-value managed metadata columns

- Single-value people and group columns

- Multiple-value people and group columns

Note

As the number of look up columns increases beyond the default value in a list, you will come across performance issues in your farm.