CODEWITHSUNDEEP
c#sqlentity-frameworkout-of-memory
sharmila
sharmila

Reputation: 85

OutOfMemory Exception for Where clause

I am using entity Framework 6 with LazyLoadEnabled = false configuration nothing else.I am using UnitOfwork repository pattern in my project. And I have around 1,50,000 records in a table with foreign key relations to around 5 tables. Now my requirement is I have to implement server side pagination.For that, first I am querying this table to get exact count after applying some basic filters(like isactive and created by user) like below :

public long Count(Func<TEntity,bool> where)
{
    return DbSet.Where(where).Count();
}

then I am applying some search string filter and include some foreign references like below :

public IQueryable<TEntity> GetWithInclude(Expression<Func<TEntity, bool>> predicate, params string[] include)
{
    IQueryable<TEntity> query = this.DbSet;
    query = include.Aggregate(query, (current, inc) => current.Include(inc));
    return query.Where(predicate);
}

but in both methods, I am getting OutOfMemory exception since I have used Where clause . Kindly help me to get rid of this problem.

Upvotes: 0

Views: 127

Answers (2)

DavidG
DavidG

Reputation: 118937

This is really just to expand on the answer from Daniel. Because your Count method takes a Func<TEntity,bool>, you are forcing the compiler to choose Enumerable.Where instead of the more specific Queryable.Where. This forces your entire DbSet to be materialised into memory - all 1,500,000 rows. So change the method signature to take an Expression instead, and while you're there, you don't need to call Where, instead use the other overload of Count:

public long Count(Expression<Func<TEntity,bool>> where)
{
    return DbSet.Count(where);
}

Upvotes: 0

Daniel A. White
Daniel A. White

Reputation: 190915

Perhaps you should change your signature to include Expression to avoid the full load of the records into memory.

public long Count(Expression<Func<TEntity,bool>> where)

Aside: LINQ already has a Count operator that you can use.

Upvotes: 2

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