Compare PostgreSQL and SQL Server regarding CanConnectAsync

Program.cs

using System.Diagnostics;
using Microsoft.EntityFrameworkCore;
using Testcontainers.MsSql;
using Testcontainers.PostgreSql;

var msSqlContainer = new MsSqlBuilder()
    .WithImage(MsSqlBuilder.MsSqlImage.Replace("mcr.microsoft.com/", string.Empty))
    .Build();
await msSqlContainer.StartAsync();
SqlServerContext.Port = msSqlContainer.GetMappedPublicPort(MsSqlBuilder.MsSqlPort);

var postgresContainer = new PostgreSqlBuilder()
    .WithImage(PostgreSqlBuilder.PostgreSqlImage)
    .Build();
await postgresContainer.StartAsync();
PostgresContext.Port = postgresContainer.GetMappedPublicPort(PostgreSqlBuilder.PostgreSqlPort);

var factories = new List<Func<DbContext>> { () => new SqlServerContext(), () => new PostgresContext() };
const int runs = 10;

var results = new Dictionary<string, double>(runs*factories.Count);
foreach (var factory in factories)
{
    var tester = new Tester(factory);
    await tester.InitializeAsync();
    results = results.Concat(await tester.TestAsync(runs)).ToDictionary(x => x.Key, x => x.Value);
}

foreach (var (key, value) in results)
{
    Console.WriteLine($"{key}: {value} ms");
}

public class Tester
{
    private readonly Func<DbContext> _factory;

    public Tester(Func<DbContext> factory) => _factory = factory;

    public async Task InitializeAsync()
    {
        using var context = _factory();
        await context.Database.EnsureCreatedAsync();
    }
    
    public async Task<Dictionary<string, double>> TestAsync(int runs)
    {
        var results = new Dictionary<string, double>(runs);
        
        for (int i = 0; i < runs; i++)
        {
            using var context = _factory();
            var stopwatch = Stopwatch.StartNew();
            await context.Database.CanConnectAsync();
            stopwatch.Stop();
            results.Add($"{context.GetType().Name}-{i}", stopwatch.ElapsedMilliseconds);
        }

        return results;
    }
}

public class SqlServerContext : DbContext
{
    public static int Port { get; set; }

    readonly string _connectionString = $"server=127.0.0.1,{Port};user id={MsSqlBuilder.DefaultUsername};password={MsSqlBuilder.DefaultPassword};database={MsSqlBuilder.DefaultDatabase};encrypt=false";

    protected override void OnConfiguring(DbContextOptionsBuilder options)
        => options.UseSqlServer(_connectionString);
}

public class PostgresContext : DbContext
{
    public static int Port { get; set; }

    readonly string _connectionString = $"Host=127.0.0.1;Port={Port};Database={PostgreSqlBuilder.DefaultDatabase};User Id={PostgreSqlBuilder.DefaultUsername};Password={PostgreSqlBuilder.DefaultPassword};Include Error Detail=true;";

    protected override void OnConfiguring(DbContextOptionsBuilder options)
        => options.UseNpgsql(_connectionString);
}