Queryable Vs. IEnumerable in terms of LINQ to SQL queries

Few days ago I was working on my project which is having Linq to Sql as database layer. I got requirement to get the first of all employee who's designation starts with "soft".

I get fired below query and got the result in IEnumerable varible

  IEnumerable<employee> emp =          dc.Employees.Where(x => x.Desc.StartsWith("soft")); emp = emp.Take(1); 

But later on I found there it's taking too much time to get the count.
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