“Value does not fall within the expected range” for Lookup field and its relation to Resource throttling of the web application

Question

I was querying a list having many columns, some of them being look-ups. My query was to return a SPListItem based on one ID. Now, when I want to bind the value of look-up field from the SPListItem to a drop-down or text field, I came across an interesting situation.

I used the below code for getting the look-up value:

SPFieldLookupValue fieldLookupValue1 = new SPFieldLookupValue(ListItem["LookupField"].ToString());

if (fieldLookupValue1 != null)
   Textbox.text = fieldLookupValue1.LookupValue;

The above was working well when logged in as System Account. But it throws an error "Value does not fall within the expected range" when logged in with a user having read access or above. What is interesting is after increasing the value in "List View Lookup Threshold" under Resource throttling for the Web Application in Central Admin this issue got resolved on its own.

Can someone explain what is happening behind? What is the trade-off for increasing the values under Resource throttling?

Answer 1

As Cameron pointed out, it's because of performance reason. Administrators got permission to query above the default 8 columns, standard user's do not.

Microsoft states the following on their site about list performance. See the part Lookup columns and list views in the article. There's some good graphs showing what happens with the SQL performance as well.

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.

Designing large lists and maximizing list performance