Indexed properties with Linq?

In a database we create indexes on columns that we want to query with joins.

Does Linq to objects facilitate this in any way?

I imagine that search performance could be (much) improved when somehow List's can be supported by binary trees (indexes) in memory that are mapped to spec开发者_运维问答ific properties of T.

I am thinking of Lists that do not have to be optimized for inserts or deletes.

One could turn off the index for another optimization.

No; LINQ does not use indexes.

Instead, you can use i4o, which does.

Note that many LINQ operations, such as Distinct, Join, GroupBy, and others, will build a hasttable (or hashset, as appropriate) to avoid O(n²) performance.
For more information, see Jon Skeet's EduLINQ series.