System.UnauthorizedAccessException when inserting

Today I found LiteDB and took some very basic tests:

• I’ve used the Basic example from www.litedb.org
• Put it into a 1000 loop.

What happens next will shock you 😉:

After several iterations (sometimes 28, sometimes 101, sometimes …) I get an exception:

System.UnauthorizedAccessException
Access to MyData-journal.db was denied.

This is the complete source code of my .NET 4.7 console application:

namespace TestNoSQL
{
    using LiteDB;
    using System;
    using System.Diagnostics;
    using System.IO;
    using System.Reflection;

    // Basic example
    public class Customer
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string[] Phones { get; set; }
        public bool IsActive { get; set; }
    }

    internal static class Program
    {
        private static readonly string _path =
            Path.GetDirectoryName(Assembly.GetEntryAssembly().Location).TrimEnd('\\') + 
            @"\MyData.db";

        private static void Main(string[] args)
        {
            const int count = 1000;

            var sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < count; ++i)
            {
                one();
            }
            sw.Stop();

            Console.WriteLine($@"{count} times '{nameof(one)}' took. {sw.Elapsed}.");
        }

        private static void one()
        {
            // Open database (or create if not exits)
            using (var db = new LiteDatabase(_path))
            {
                // Get customer collection
                var customers = db.GetCollection<Customer>("customers");

                // Create your new customer instance
                var customer = new Customer
                {
                    Name = "John Doe",
                    Phones = new string[] { "8000-0000", "9000-0000" },
                    IsActive = true
                };

                // Insert new customer document (Id will be auto-incremented)
                customers.Insert(customer);

                // Update a document inside a collection
                customer.Name = "Joana Doe";

                customers.Update(customer);
            }
        }
    }
}

My question:

Is this a design limitation or am I doing something significantly wrong?

[mbdavid]

Huge difference between Access and LiteDB 😄

LiteDB is 100% managed .NET code, runs in-process. Read access are optimized to re-use cached block pages, so disk access are reduced too.

[UweKeim]

One last addition, my comparison between MS Access and LiteDB:

Access             of 1000 WRITE iterations took 00:00:38.9010116.
LiteDB             of 1000 WRITE iterations took 00:00:02.0247147.
LiteDB (in-memory) of 1000 WRITE iterations took 00:00:00.1703879.

Access             of 1000 READ  iterations took 00:00:47.4544505.
LiteDB             of 1000 READ  iterations took 00:00:00.0133699.
LiteDB (in-memory) of 1000 READ  iterations took 00:00:00.0122957.

This is based on the Basic example with the Customer class.

I’ve also added a test based on this ticket in order to compare with an in-memory version of the LiteDB database file.