RavenDb OutOfMemoryException with batch export loop

namespace ImdbLoader
{
    class Program
    {
        private static DocumentStore Store;
        private static Encoding encoding = Encoding.GetEncoding(1252);

        static void Main(string[] args)
        {
            Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
            Reinitialize();

            Test();

            Console.WriteLine("Press any key to close...");
            Console.ReadLine();
        }

        private static void Reinitialize()
        {
            if (Store != null)
            {
                Store.Dispose();
                Store = null;
            }

            Store = new DocumentStore { ConnectionStringName = "RavenDB" };
            Store.Conventions.IdentityPartsSeparator = "-";
            Store.Initialize();
        }

        private static void Test()
        {
            Console.WriteLine(@"Exporting all MediaIds to file...");
            var mediaIdsPath = Path.GetTempFileName();
            var mediaIdsOrderedPath = Path.GetTempFileName();
            using (var f = File.Open(mediaIdsPath, FileMode.Truncate, FileAccess.Write, FileShare.Read))
            {
                using (var sw = new StreamWriter(f, encoding))
                {
                    int offset = 0, num = 0, i = 0, batchSize = 1024;

                    while (true)
                    {
                        if ((num = WriteDocs(offset, batchSize, sw)) == 0) break;
                        offset += num;

                        //uncomment to fix OutOfMemoryException
                        //if (++i % 10 == 0) Reinitialize();
                    }
                }
            }
        }

        private static int WriteDocs(int offset, int batchSize, StreamWriter sw)
        {
            int num = 0;

            using (var session = Store.OpenSession())
            {
                using (var foo = session.Advanced.DocumentStore.DisableAggressiveCaching())
                {
                    var batch = session.Query<ImdbMedia>("Raven/DocumentsByEntityName")
                        .Skip(offset)
                        .Take(batchSize)
                        .Select(x => new { GlobalId = x.Id, ImdbFullTitle = x.ImdbFullTitle });

                    foreach (var item in batch)
                    {
                        sw.Write(string.Format("{0}{1}\t\t\t{2}", (offset + num++ > 0 ? "\n" : ""), item.ImdbFullTitle, item.GlobalId));
                    }

                    sw.Flush();
                }
            }

            return num;
        }
    }
}