diff --git a/src/CloudStructures/IRedisConnection.cs b/src/CloudStructures/IRedisConnection.cs
new file mode 100644
index 0000000..b1618f0
--- /dev/null
+++ b/src/CloudStructures/IRedisConnection.cs
@@ -0,0 +1,25 @@
+using StackExchange.Redis;
+
+namespace CloudStructures
+{
+    /// <summary>
+    /// Represents a Redis connection interface.
+    /// </summary>
+    public interface IRedisConnection
+    {
+        /// <summary>
+        /// Gets the asynchronous database accessor for Redis.
+        /// </summary>
+        IDatabaseAsync Database { get; }
+
+        /// <summary>
+        /// Gets the Redis transaction object.
+        /// </summary>
+        ITransaction Transaction { get; }
+
+        /// <summary>
+        /// Gets an array of Redis server instances connected to the current multiplexer.
+        /// </summary>
+        IServer[] Servers { get; }
+    }
+}
diff --git a/src/CloudStructures/Internals/EnumerableExtensions.cs b/src/CloudStructures/Internals/EnumerableExtensions.cs
index de6a4e6..7440b0a 100644
--- a/src/CloudStructures/Internals/EnumerableExtensions.cs
+++ b/src/CloudStructures/Internals/EnumerableExtensions.cs
@@ -22,7 +22,7 @@ public static bool IsEmpty<T>(this IEnumerable<T> source)
 
 
     /// <summary>
-    /// Projects each element of a sequance into new form with state. 
+    /// Projects each element of a sequance into new form with state.
     /// </summary>
     /// <typeparam name="T">Element type</typeparam>
     /// <typeparam name="TState">State type</typeparam>
@@ -50,7 +50,7 @@ public static IEnumerable<T> Materialize<T>(this IEnumerable<T>? source, bool nu
         if (source is null)
         {
             if (nullToEmpty)
-                return [];
+                return new T[0];
 
 #if NET6_0_OR_GREATER
             ArgumentNullException.ThrowIfNull(source);
diff --git a/src/CloudStructures/RedisConnection.cs b/src/CloudStructures/RedisConnection.cs
index 30b37cb..d16dc92 100644
--- a/src/CloudStructures/RedisConnection.cs
+++ b/src/CloudStructures/RedisConnection.cs
@@ -1,129 +1,157 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using CloudStructures.Converters;
 using CloudStructures.Internals;
 using StackExchange.Redis;
 
-namespace CloudStructures;
-
-
-
-/// <summary>
-/// Provides connection to the server.
-/// </summary>
-/// <remarks>This connection needs to be used w/o destroying. Please hold as static field or static property.</remarks>
-public sealed class RedisConnection
+namespace CloudStructures
 {
-    #region Properties
-    /// <summary>
-    /// Gets configuration.
-    /// </summary>
-    public RedisConfig Config { get; }
-
-
-    /// <summary>
-    /// Gets value converter.
-    /// </summary>
-    internal ValueConverter Converter { get; }
-
-
-    /// <summary>
-    /// Gets connection event handler.
-    /// </summary>
-    private IConnectionEventHandler? Handler { get; }
-
-
-    /// <summary>
-    /// Gets logger.
-    /// </summary>
-    private TextWriter? Logger { get; }
-
-
-    /// <summary>
-    /// Gets an interactive connection to a database inside redis.
-    /// </summary>
-    internal IDatabaseAsync Database
-        => this.Config.Database.HasValue
-        ? this.GetConnection().GetDatabase(this.Config.Database.Value)
-        : this.GetConnection().GetDatabase();
-
-
-    /// <summary>
-    /// Gets a transaction.
-    /// </summary>
-    internal ITransaction Transaction
-        => ((IDatabase)this.Database).CreateTransaction();
-
-
     /// <summary>
-    /// Gets target servers.
+    /// Provides connection to the server.
     /// </summary>
-    internal IServer[] Servers
-        => this.Config.Options
-        .EndPoints
-        .Select(this.GetConnection(), static (x, c) => c.GetServer(x))
-        .ToArray();
-    #endregion
+    /// <remarks>This connection needs to be used w/o destroying. Please hold as static field or static property.</remarks>
+    public sealed class RedisConnection
+    {
+        #region Properties
+        /// <summary>
+        /// Gets configuration.
+        /// </summary>
+        public RedisConfig? Config { get; }
+
+        /// <summary>
+        /// Gets value converter.
+        /// </summary>
+        internal ValueConverter Converter { get; }
+
+
+        /// <summary>
+        /// Gets connection event handler.
+        /// </summary>
+        private IConnectionEventHandler? Handler { get; }
+
+
+        /// <summary>
+        /// Gets logger.
+        /// </summary>
+        private TextWriter? Logger { get; }
+
+
+        /// <summary>
+        /// Gets an interactive connection to a database inside redis.
+        /// </summary>
+        internal IDatabaseAsync Database => _database ?? (this.Config?.Database.HasValue ?? false
+            ? this.GetConnection().GetDatabase(this.Config.Database.Value)
+            : this.GetConnection().GetDatabase());
+
+        /// <summary>
+        /// Gets a transaction.
+        /// </summary>
+        public ITransaction Transaction => ((IDatabase)Database).CreateTransaction();
+
+        /// <summary>
+        /// Gets target servers.
+        /// </summary>
+        public IServer[] Servers
+        {
+            get
+            {
+                if (this.Config != null)
+                {
+                    return this.Config.Options
+                        .EndPoints
+                        .Select(this.GetConnection(), static (x, c) => c.GetServer(x))
+                        .ToArray();
+                }
+                else
+                {
+                    var multiplexer = Database.Multiplexer;
+                    var endpoints = multiplexer.GetEndPoints();
 
+                    return endpoints.Select(endpoint => multiplexer.GetServer(endpoint))
+                        .ToArray();
+                }
+            }
+        }
+        #endregion
+
+
+        #region Constructors
+        /// <summary>
+        /// Creates instance with RedisConfig.
+        /// </summary>
+        /// <param name="config"></param>
+        /// <param name="converter">If null, use <see cref="SystemTextJsonConverter"/> as default.</param>
+        /// <param name="handler"></param>
+        /// <param name="logger"></param>
+        public RedisConnection(RedisConfig config, IValueConverter? converter = null, IConnectionEventHandler? handler = null, TextWriter? logger = null)
+        {
+            this.Config = config;
+            this.Converter = new(converter);
+            this.Handler = handler;
+            this.Logger = logger;
+        }
 
-    #region Constructors
-    /// <summary>
-    /// Creates instance.
-    /// </summary>
-    /// <param name="config"></param>
-    /// <param name="converter">If null, use <see cref="SystemTextJsonConverter"/> as default.</param>
-    /// <param name="handler"></param>
-    /// <param name="logger"></param>
-    public RedisConnection(RedisConfig config, IValueConverter? converter = null, IConnectionEventHandler? handler = null, TextWriter? logger = null)
-    {
-        this.Config = config;
-        this.Converter = new(converter);
-        this.Handler = handler;
-        this.Logger = logger;
-    }
-    #endregion
+        /// <summary>
+        /// Creates a RedisConnection instance with a pre-existing IDatabaseAsync instance.
+        /// </summary>
+        /// <param name="database">Pre-existing IDatabaseAsync instance.</param>
+        /// <param name="converter">Optional value converter.</param>
+        /// <param name="handler">Connection event handler.</param>
+        /// <param name="logger">Logger.</param>
+        public RedisConnection(IDatabaseAsync database, IValueConverter? converter = null, IConnectionEventHandler? handler = null, TextWriter? logger = null)
+        {
+            this._database = database ?? throw new ArgumentNullException(nameof(database));
+            this.Converter = new ValueConverter(converter);
+            this.Handler = handler;
+            this.Logger = logger;
+        }
+        #endregion
 
 
-    #region Connection management
-    /// <summary>
-    /// Gets underlying connection.
-    /// </summary>
-    /// <returns></returns>
-    public ConnectionMultiplexer GetConnection()
-    {
-        lock (this._gate)
+        #region Connection management
+        /// <summary>
+        /// Gets underlying connection.
+        /// </summary>
+        /// <returns></returns>
+        public ConnectionMultiplexer GetConnection()
         {
-            if (this._connection is null || !this._connection.IsConnected)
+            lock (this._gate)
             {
-                try
+                if (this._connection is null || !this._connection.IsConnected)
                 {
-                    //--- create inner connection
-                    var stopwatch = Stopwatch.StartNew();
-                    this._connection = ConnectionMultiplexer.Connect(this.Config.Options, this.Logger);
-                    stopwatch.Stop();
-                    this.Handler?.OnConnectionOpened(this, new(stopwatch.Elapsed));
-
-                    //--- attach events
-                    this._connection.ConfigurationChanged += (_, e) => this.Handler?.OnConfigurationChanged(this, e);
-                    this._connection.ConfigurationChangedBroadcast += (_, e) => this.Handler?.OnConfigurationChangedBroadcast(this, e);
-                    this._connection.ConnectionFailed += (_, e) => this.Handler?.OnConnectionFailed(this, e);
-                    this._connection.ConnectionRestored += (_, e) => this.Handler?.OnConnectionRestored(this, e);
-                    this._connection.ErrorMessage += (_, e) => this.Handler?.OnErrorMessage(this, e);
-                    this._connection.HashSlotMoved += (_, e) => this.Handler?.OnHashSlotMoved(this, e);
-                    this._connection.InternalError += (_, e) => this.Handler?.OnInternalError(this, e);
-                    this._connection.ServerMaintenanceEvent += (_, e) => this.Handler?.OnServerMaintenanceEvent(this, e);
-                }
-                catch
-                {
-                    this._connection = null;
-                    throw;
+                    try
+                    {
+                        //--- create inner connection
+                        var stopwatch = Stopwatch.StartNew();
+                        this._connection = ConnectionMultiplexer.Connect(this.Config!.Options, this.Logger);
+                        stopwatch.Stop();
+                        this.Handler?.OnConnectionOpened(this, new(stopwatch.Elapsed));
+
+                        //--- attach events
+                        this._connection.ConfigurationChanged += (_, e) => this.Handler?.OnConfigurationChanged(this, e);
+                        this._connection.ConfigurationChangedBroadcast += (_, e) => this.Handler?.OnConfigurationChangedBroadcast(this, e);
+                        this._connection.ConnectionFailed += (_, e) => this.Handler?.OnConnectionFailed(this, e);
+                        this._connection.ConnectionRestored += (_, e) => this.Handler?.OnConnectionRestored(this, e);
+                        this._connection.ErrorMessage += (_, e) => this.Handler?.OnErrorMessage(this, e);
+                        this._connection.HashSlotMoved += (_, e) => this.Handler?.OnHashSlotMoved(this, e);
+                        this._connection.InternalError += (_, e) => this.Handler?.OnInternalError(this, e);
+                        this._connection.ServerMaintenanceEvent += (_, e) => this.Handler?.OnServerMaintenanceEvent(this, e);
+                    }
+                    catch
+                    {
+                        this._connection = null;
+                        throw;
+                    }
                 }
+                return this._connection;
             }
-            return this._connection;
         }
+
+        private readonly object _gate = new();
+        private ConnectionMultiplexer? _connection = null;
+        private readonly IDatabaseAsync? _database = null;
+        #endregion
     }
-    private readonly object _gate = new();
-    private ConnectionMultiplexer? _connection = null;
-    #endregion
 }
diff --git a/src/CloudStructures/Structures/RedisSortedSet.cs b/src/CloudStructures/Structures/RedisSortedSet.cs
index 210f7ca..566fcac 100644
--- a/src/CloudStructures/Structures/RedisSortedSet.cs
+++ b/src/CloudStructures/Structures/RedisSortedSet.cs
@@ -131,7 +131,7 @@ public Task<long> CombineAndStoreAsync(SetOperation operation, RedisSortedSet<T>
 #if NETSTANDARD2_1 || NET5_0_OR_GREATER
         var keys = others.Select(static x => x.Key).Append(this.Key).ToArray();
 #else
-        var keys = others.Select(static x => x.Key).Concat([this.Key]).ToArray();
+        var keys = others.Select(x => x.Key).Concat(new[] { this.Key }).ToArray();
 #endif
         return this.Connection.Database.SortedSetCombineAndStoreAsync(operation, destination.Key, keys, weights, aggregate, flags);
     }