LINQ value.contains function error

Question

m facing the following error while using LINQ with RavenDB

`Contains is not supported, doing a substring match over a text field is a very slow operation, and is not allowed using the Linq API.
The recommended method is to use full text search (mark the field as Analyzed and use the Search() method to query it.`

here is my LINQ Query


`query = from u in Session.Query<Article>() where u.Tags.Contains(tags) orderby u.CreationDate descending select `

plz help me solve my problem