diff --git a/PartitionFileStorageTest/Program.cs b/PartitionFileStorageTest/Program.cs
index 83ff367..d78393d 100644
--- a/PartitionFileStorageTest/Program.cs
+++ b/PartitionFileStorageTest/Program.cs
@@ -102,10 +102,11 @@ namespace PartitionFileStorageTest
 
         private static void BuildStore(string source, string root)
         {
-            var options = new IStoreOptions<ulong, ulong, byte[], Metadata>
+            var options = new StoreOptions<ulong, ulong, byte[], Metadata>
             {
+                Index = new IndexOptions { Enabled = true, FileIndexCount = 256 },
                 RootFolder = root,
-                FilePartition = new StoreFilePartition<ulong, Metadata>("Last three digits", (ctn, date) => (ctn % 1000).ToString()),
+                FilePartition = new StoreFilePartition<ulong, Metadata>("Last three digits", (ctn, date) => (ctn % 512).ToString()),
                 MergeFunction = list =>
                 {
                     ulong s = 0;
@@ -118,12 +119,11 @@ namespace PartitionFileStorageTest
                 },
                 KeyComparer = (left, right) => left == right ? 0 : (left < right) ? -1 : 1,
             };
-            options.Index.Enabled = true;
             var store = new Store<ulong, ulong, byte[], Metadata>(options);
 
 
-            var storeIncoming = store.CreateAccessor(new Metadata { Date = new DateTime(2022, 11, 08), Incoming = true });
-            var storeOutcoming = store.CreateAccessor(new Metadata { Date = new DateTime(2022, 11, 08), Incoming = false });
+            var storeIncoming = store.CreateBuilder(new Metadata { Date = new DateTime(2022, 11, 08), Incoming = true });
+            var storeOutcoming = store.CreateBuilder(new Metadata { Date = new DateTime(2022, 11, 08), Incoming = false });
             var parser = new CallRecordParser();
             var sw = new Stopwatch();
             sw.Start();
@@ -165,17 +165,13 @@ namespace PartitionFileStorageTest
             Console.WriteLine($"Rebuild indexes: {sw.ElapsedMilliseconds}ms");
         }
 
-        private static void TestReading(string source, string root)
+        private static void TestReading(string root)
         {
-            var options = new IStoreOptions<ulong, ulong, byte[], Metadata>
+            var options = new StoreOptions<ulong, ulong, byte[], Metadata>
             {
-                Index = new IndexOptions
-                {
-                    Enabled = false,
-                    FileIndexCount = 64
-                },
+                Index = new IndexOptions { Enabled = true, FileIndexCount = 256 },
                 RootFolder = root,
-                FilePartition = new StoreFilePartition<ulong, Metadata>("Last three digits", (ctn, date) => (ctn % 1000).ToString()),
+                FilePartition = new StoreFilePartition<ulong, Metadata>("Last three digits", (ctn, date) => (ctn % 512).ToString()),
                 MergeFunction = list =>
                 {
                     ulong s = 0;
@@ -183,10 +179,10 @@ namespace PartitionFileStorageTest
                 },
                 Partitions = new List<StoreCatalogPartition<Metadata>>
                 {
-                    new StoreCatalogPartition<Metadata>("timestamp", m => m.Date.ToString("yyyyMMdd")),
-                    new StoreCatalogPartition<Metadata>("timestamp", m => m.Incoming ? "incoming" : "outcoming")
+                    new StoreCatalogPartition<Metadata>("Date", m => m.Date.ToString("yyyyMMdd")),
+                    new StoreCatalogPartition<Metadata>("Date", m => m.Incoming ? "incoming" : "outcoming")
                 },
-                KeyComparer = (left, right) => left == right ? 0 : (left < right) ? -1 : 1
+                KeyComparer = (left, right) => left == right ? 0 : (left < right) ? -1 : 1,
             };
             var store = new Store<ulong, ulong, byte[], Metadata>(options);
             var request = new StoreSearchRequest<ulong, Metadata>
@@ -245,61 +241,12 @@ namespace PartitionFileStorageTest
             return arr;
         }
 
-        private static KeyIndex<long> BinarySearchInIndex(KeyIndex<long>[] index,
-            long key,
-            Func<long, long, int> keyComparer,
-            ref int position)
-        {
-            if (index == null || index.Length == 0)
-            {
-                return new KeyIndex<long> { Key = key, Offset = 0 };
-            }
-            int left = position;
-            int right = index.Length - 1;
-            int mid = 0;
-            long test;
-            while (left <= right)
-            {
-                mid = (int)Math.Floor((right + left) / 2d);
-                test = index[mid].Key;
-                var c = keyComparer(test, key);
-                if (c < 0)
-                {
-                    left = mid + 1;
-                }
-                else if (c > 0)
-                {
-                    right = mid - 1;
-                }
-                else
-                {
-                    position = mid;
-                    return index[mid];
-                }
-            }
-            position = mid;
-            return index[mid];
-        }
-
         static void Main(string[] args)
         {
             var root = @"H:\temp";
             var source = @"H:\319a9c31-d823-4dd1-89b0-7fb1bb9c4859.txt";
             //BuildStore(source, root);
-            TestReading(source, root);
-
-            /*
-            Func<long, long, int> keyComparer =
-                (left, right) =>
-                    (left == right) ? 0 : (left < right) ? -1 : 1;
-            var indexes = Generate(77);
-            int position = 0;
-            for (long i = 65; i < 700; i++)
-            {
-                var ind = BinarySearchInIndex(indexes, i, keyComparer, ref position);
-                Console.WriteLine($"{i}: {ind.Offset}. [{ind.Key}]");
-            }
-            */
+            TestReading(root);
             Console.ReadKey();
         }
     }
diff --git a/ZeroLevel/Services/PartitionStorage/Indexes/KeyIndex.cs b/ZeroLevel/Services/PartitionStorage/Indexes/KeyIndex.cs
new file mode 100644
index 0000000..7afd3e2
--- /dev/null
+++ b/ZeroLevel/Services/PartitionStorage/Indexes/KeyIndex.cs
@@ -0,0 +1,8 @@
+namespace ZeroLevel.Services.PartitionStorage
+{
+    internal struct KeyIndex<TKey>
+    {
+        public TKey Key { get; set; }
+        public long Offset { get; set; }
+    }
+}
diff --git a/ZeroLevel/Services/PartitionStorage/StorePartitionIndex.cs b/ZeroLevel/Services/PartitionStorage/Indexes/StorePartitionSparseIndex.cs
similarity index 94%
rename from ZeroLevel/Services/PartitionStorage/StorePartitionIndex.cs
rename to ZeroLevel/Services/PartitionStorage/Indexes/StorePartitionSparseIndex.cs
index d4a4c17..9049701 100644
--- a/ZeroLevel/Services/PartitionStorage/StorePartitionIndex.cs
+++ b/ZeroLevel/Services/PartitionStorage/Indexes/StorePartitionSparseIndex.cs
@@ -5,13 +5,7 @@ using ZeroLevel.Services.Serialization;
 
 namespace ZeroLevel.Services.PartitionStorage
 {
-    internal struct KeyIndex<TKey>
-    {
-        public TKey Key { get; set; }
-        public long Offset { get; set; }
-    }
-
-    internal class StorePartitionIndex<TKey, TMeta>
+    internal class StorePartitionSparseIndex<TKey, TMeta>
         : IStorePartitionIndex<TKey>
     {
         private readonly Dictionary<string, KeyIndex<TKey>[]> _indexCachee
@@ -22,7 +16,7 @@ namespace ZeroLevel.Services.PartitionStorage
         private readonly string _indexFolder;
         private readonly bool _indexExists = false;
         private readonly TMeta _meta;
-        public StorePartitionIndex(string partitionFolder, TMeta meta,
+        public StorePartitionSparseIndex(string partitionFolder, TMeta meta,
             StoreFilePartition<TKey, TMeta> filePartition,
             Func<TKey, TKey, int> keyComparer)
         {
diff --git a/ZeroLevel/Services/PartitionStorage/IStore.cs b/ZeroLevel/Services/PartitionStorage/Interfaces/IStore.cs
similarity index 79%
rename from ZeroLevel/Services/PartitionStorage/IStore.cs
rename to ZeroLevel/Services/PartitionStorage/Interfaces/IStore.cs
index 100a028..884edc8 100644
--- a/ZeroLevel/Services/PartitionStorage/IStore.cs
+++ b/ZeroLevel/Services/PartitionStorage/Interfaces/IStore.cs
@@ -13,9 +13,11 @@ namespace ZeroLevel.Services.PartitionStorage
     /// <typeparam name="TMeta">Meta information for partition search</typeparam>
     public interface IStore<TKey, TInput, TValue, TMeta>
     {
-        IStorePartitionAccessor<TKey, TInput, TValue> CreateAccessor(TMeta info);
+        IStorePartitionBuilder<TKey, TInput, TValue> CreateBuilder(TMeta info);
+
+        IStorePartitionBuilder<TKey, TInput, TValue> CreateMergeAccessor(TMeta info, Func<TValue, IEnumerable<TInput>> decompressor);
 
-        IStorePartitionAccessor<TKey, TInput, TValue> CreateMergeAccessor(TMeta info, Func<TValue, IEnumerable<TInput>> decompressor);
+        IStorePartitionAccessor<TKey, TInput, TValue> CreateAccessor(TMeta info);
 
         Task<StoreSearchResult<TKey, TValue, TMeta>> Search(StoreSearchRequest<TKey, TMeta> searchRequest);
     }
diff --git a/ZeroLevel/Services/PartitionStorage/IStorePartitionAccessor.cs b/ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionAccessor.cs
similarity index 54%
rename from ZeroLevel/Services/PartitionStorage/IStorePartitionAccessor.cs
rename to ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionAccessor.cs
index 7eb04ed..3a19b76 100644
--- a/ZeroLevel/Services/PartitionStorage/IStorePartitionAccessor.cs
+++ b/ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionAccessor.cs
@@ -1,28 +1,16 @@
-using System;
-using System.Collections.Generic;
+using System.Collections.Generic;
 
 namespace ZeroLevel.Services.PartitionStorage
 {
     /// <summary>
-    /// Provides read-write operations in catalog partition
+    /// Provides read/reindex operations in catalog partition
     /// </summary>
     /// <typeparam name="TKey">Key type</typeparam>
     /// <typeparam name="TInput">Type of one input value</typeparam>
     /// <typeparam name="TValue">Type of records aggregate</typeparam>
     public interface IStorePartitionAccessor<TKey, TInput, TValue>
-        : IDisposable
+        : IStorePartitionBase<TKey, TInput, TValue>
     {
-        string GetCatalogPath();
-        /// <summary>
-        /// Has any files
-        /// </summary>
-        int CountDataFiles();
-        /// <summary>
-        /// Remove all files
-        /// </summary>
-        void DropData();
-
-        #region API !only after data compression!
         /// <summary>
         /// Rebuild indexes
         /// </summary>
@@ -37,18 +25,5 @@ namespace ZeroLevel.Services.PartitionStorage
         IEnumerable<StorePartitionKeyValueSearchResult<TKey, TValue>> Find(IEnumerable<TKey> keys);
         IEnumerable<StorePartitionKeyValueSearchResult<TKey, TValue>> Iterate();
         IEnumerable<StorePartitionKeyValueSearchResult<TKey, TValue>> IterateKeyBacket(TKey key);
-        #endregion
-
-        #region API !only before data compression!
-        /// <summary>
-        /// Save one record
-        /// </summary>
-        void Store(TKey key, TInput value);
-        /// <summary>
-        /// Complete the recording and perform the conversion of the records from 
-        /// (TKey; TInput) to (TKey; TValue)
-        /// </summary>
-        void CompleteAddingAndCompress();
-        #endregion
     }
 }
diff --git a/ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionBase.cs b/ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionBase.cs
new file mode 100644
index 0000000..a24c544
--- /dev/null
+++ b/ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionBase.cs
@@ -0,0 +1,24 @@
+using System;
+
+namespace ZeroLevel.Services.PartitionStorage
+{
+    /// <summary>
+    /// Provides common operations in catalog partition
+    /// </summary>
+    /// <typeparam name="TKey">Key type</typeparam>
+    /// <typeparam name="TInput">Type of one input value</typeparam>
+    /// <typeparam name="TValue">Type of records aggregate</typeparam>
+    public interface IStorePartitionBase<TKey, TInput, TValue>
+        : IDisposable
+    {
+        string GetCatalogPath();
+        /// <summary>
+        /// Has any files
+        /// </summary>
+        int CountDataFiles();
+        /// <summary>
+        /// Remove all files
+        /// </summary>
+        void DropData();
+    }
+}
diff --git a/ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionBuilder.cs b/ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionBuilder.cs
new file mode 100644
index 0000000..26d6379
--- /dev/null
+++ b/ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionBuilder.cs
@@ -0,0 +1,23 @@
+namespace ZeroLevel.Services.PartitionStorage
+{
+    /// <summary>
+    /// Provides write operations in catalog partition
+    /// </summary>
+    /// <typeparam name="TKey">Key type</typeparam>
+    /// <typeparam name="TInput">Type of one input value</typeparam>
+    /// <typeparam name="TValue">Type of records aggregate</typeparam>
+    public interface IStorePartitionBuilder<TKey, TInput, TValue>
+       : IStorePartitionBase<TKey, TInput, TValue>
+    {
+        /// <summary>
+        /// Save one record
+        /// </summary>
+        void Store(TKey key, TInput value);
+        /// <summary>
+        /// Complete the recording and perform the conversion of the records from 
+        /// (TKey; TInput) to (TKey; TValue)
+        /// </summary>
+        void CompleteAddingAndCompress();
+        void RebuildIndex();
+    }
+}
diff --git a/ZeroLevel/Services/PartitionStorage/IStorePartitionIndex.cs b/ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionIndex.cs
similarity index 67%
rename from ZeroLevel/Services/PartitionStorage/IStorePartitionIndex.cs
rename to ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionIndex.cs
index bf4eb35..8ff9f9c 100644
--- a/ZeroLevel/Services/PartitionStorage/IStorePartitionIndex.cs
+++ b/ZeroLevel/Services/PartitionStorage/Interfaces/IStorePartitionIndex.cs
@@ -1,6 +1,4 @@
-using System.Collections.Generic;
-
-namespace ZeroLevel.Services.PartitionStorage
+namespace ZeroLevel.Services.PartitionStorage
 {
     internal interface IStorePartitionIndex<TKey>
     {
diff --git a/ZeroLevel/Services/PartitionStorage/Options/CacheOptions.cs b/ZeroLevel/Services/PartitionStorage/Options/CacheOptions.cs
new file mode 100644
index 0000000..6e22ec8
--- /dev/null
+++ b/ZeroLevel/Services/PartitionStorage/Options/CacheOptions.cs
@@ -0,0 +1,17 @@
+namespace ZeroLevel.Services.PartitionStorage
+{
+    public class CacheOptions
+    {
+        public bool UsePersistentCache { get; set; }
+
+        public string PersistentCacheFolder { get; set; } = "cachee";
+
+        public int PersistentCacheRemoveTimeoutInSeconds { get; set; } = 3600;
+
+        public bool UseMemoryCache { get; set; }
+
+        public int MemoryCacheLimitInMb { get; set; } = 1024;
+
+        public int MemoryCacheRemoveTimeoutInSeconds { get; set; } = 900;
+    }
+}
diff --git a/ZeroLevel/Services/PartitionStorage/Options/IndexOptions.cs b/ZeroLevel/Services/PartitionStorage/Options/IndexOptions.cs
new file mode 100644
index 0000000..e1830fc
--- /dev/null
+++ b/ZeroLevel/Services/PartitionStorage/Options/IndexOptions.cs
@@ -0,0 +1,8 @@
+namespace ZeroLevel.Services.PartitionStorage
+{
+    public class IndexOptions
+    {
+        public bool Enabled { get; set; }
+        public int FileIndexCount { get; set; } = 64;
+    }
+}
diff --git a/ZeroLevel/Services/PartitionStorage/IStoreOptions.cs b/ZeroLevel/Services/PartitionStorage/Options/StoreOptions.cs
similarity index 73%
rename from ZeroLevel/Services/PartitionStorage/IStoreOptions.cs
rename to ZeroLevel/Services/PartitionStorage/Options/StoreOptions.cs
index 189a636..f97104a 100644
--- a/ZeroLevel/Services/PartitionStorage/IStoreOptions.cs
+++ b/ZeroLevel/Services/PartitionStorage/Options/StoreOptions.cs
@@ -6,12 +6,6 @@ using ZeroLevel.Services.FileSystem;
 
 namespace ZeroLevel.Services.PartitionStorage
 {
-    public class IndexOptions
-    {
-        public bool Enabled { get; set; }
-        public int FileIndexCount { get; set; } = 64;
-    }
-
     /// <summary>
     /// Options
     /// </summary>
@@ -19,7 +13,7 @@ namespace ZeroLevel.Services.PartitionStorage
     /// <typeparam name="TInput">The value that is written in the stream</typeparam>
     /// <typeparam name="TValue">Value after compression of TInput values by duplicate keys (TInput list or similar)</typeparam>
     /// <typeparam name="TMeta">Meta information for partition search</typeparam>
-    public class IStoreOptions<TKey, TInput, TValue, TMeta>
+    public class StoreOptions<TKey, TInput, TValue, TMeta>
     {
         /// <summary>
         /// Method for key comparison
@@ -47,7 +41,17 @@ namespace ZeroLevel.Services.PartitionStorage
         /// </summary>
         public StoreFilePartition<TKey, TMeta> FilePartition { get; set; }
 
-        public IndexOptions Index { get; set; } = new IndexOptions { Enabled = false, FileIndexCount = 64 };
+        public IndexOptions Index { get; set; } = new IndexOptions
+        {
+            Enabled = false,
+            FileIndexCount = 64
+        };
+
+        public CacheOptions Cache { get; set; } = new CacheOptions
+        {
+            UseMemoryCache = false,
+            UsePersistentCache = false
+        };
 
         internal string GetFileName(TKey key, TMeta info)
         {
@@ -69,9 +73,9 @@ namespace ZeroLevel.Services.PartitionStorage
             return path;
         }
 
-        public IStoreOptions<TKey, TInput, TValue, TMeta> Clone()
+        public StoreOptions<TKey, TInput, TValue, TMeta> Clone()
         {
-            var options = new IStoreOptions<TKey, TInput, TValue, TMeta>
+            var options = new StoreOptions<TKey, TInput, TValue, TMeta>
             {
                 Index = new IndexOptions
                 {
@@ -85,7 +89,16 @@ namespace ZeroLevel.Services.PartitionStorage
                 Partitions = this.Partitions
                     .Select(p => new StoreCatalogPartition<TMeta>(p.Name, p.PathExtractor))
                     .ToList(),
-                RootFolder = this.RootFolder
+                RootFolder = this.RootFolder,
+                Cache = new CacheOptions
+                {
+                    MemoryCacheLimitInMb = this.Cache.MemoryCacheLimitInMb,
+                    MemoryCacheRemoveTimeoutInSeconds = this.Cache.MemoryCacheRemoveTimeoutInSeconds,
+                    PersistentCacheFolder = this.Cache.PersistentCacheFolder,
+                    PersistentCacheRemoveTimeoutInSeconds = this.Cache.PersistentCacheRemoveTimeoutInSeconds,
+                    UseMemoryCache = this.Cache.UseMemoryCache,
+                    UsePersistentCache = this.Cache.UsePersistentCache
+                }
             };
             return options;
         }
diff --git a/ZeroLevel/Services/PartitionStorage/StoreCatalogPartition.cs b/ZeroLevel/Services/PartitionStorage/Partition/StoreCatalogPartition.cs
similarity index 100%
rename from ZeroLevel/Services/PartitionStorage/StoreCatalogPartition.cs
rename to ZeroLevel/Services/PartitionStorage/Partition/StoreCatalogPartition.cs
diff --git a/ZeroLevel/Services/PartitionStorage/StoreFilePartition.cs b/ZeroLevel/Services/PartitionStorage/Partition/StoreFilePartition.cs
similarity index 100%
rename from ZeroLevel/Services/PartitionStorage/StoreFilePartition.cs
rename to ZeroLevel/Services/PartitionStorage/Partition/StoreFilePartition.cs
diff --git a/ZeroLevel/Services/PartitionStorage/StoreMergePartitionAccessor.cs b/ZeroLevel/Services/PartitionStorage/Partition/StoreMergePartitionAccessor.cs
similarity index 81%
rename from ZeroLevel/Services/PartitionStorage/StoreMergePartitionAccessor.cs
rename to ZeroLevel/Services/PartitionStorage/Partition/StoreMergePartitionAccessor.cs
index 15dbb55..fba4650 100644
--- a/ZeroLevel/Services/PartitionStorage/StoreMergePartitionAccessor.cs
+++ b/ZeroLevel/Services/PartitionStorage/Partition/StoreMergePartitionAccessor.cs
@@ -13,7 +13,7 @@ namespace ZeroLevel.Services.PartitionStorage
     /// 
     /// </summary>
     public class StoreMergePartitionAccessor<TKey, TInput, TValue, TMeta>
-        : IStorePartitionAccessor<TKey, TInput, TValue>
+        : IStorePartitionBuilder<TKey, TInput, TValue>
     {
         private readonly Func<TValue, IEnumerable<TInput>> _decompress;
         /// <summary>
@@ -23,8 +23,8 @@ namespace ZeroLevel.Services.PartitionStorage
         /// <summary>
         /// Write catalog
         /// </summary>
-        private readonly IStorePartitionAccessor<TKey, TInput, TValue> _temporaryAccessor;
-        public StoreMergePartitionAccessor(IStoreOptions<TKey, TInput, TValue, TMeta> options,
+        private readonly IStorePartitionBuilder<TKey, TInput, TValue> _temporaryAccessor;
+        public StoreMergePartitionAccessor(StoreOptions<TKey, TInput, TValue, TMeta> options,
             TMeta info, Func<TValue, IEnumerable<TInput>> decompress)
         {
             if (decompress == null) throw new ArgumentNullException(nameof(decompress));
@@ -33,7 +33,7 @@ namespace ZeroLevel.Services.PartitionStorage
             var tempCatalog = Path.Combine(_accessor.GetCatalogPath(), Guid.NewGuid().ToString());
             var tempOptions = options.Clone();
             tempOptions.RootFolder = tempCatalog;
-            _temporaryAccessor = new StorePartitionAccessor<TKey, TInput, TValue, TMeta>(tempOptions, info);
+            _temporaryAccessor = new StorePartitionBuilder<TKey, TInput, TValue, TMeta>(tempOptions, info);
         }
 
         private IEnumerable<StorePartitionKeyValueSearchResult<TKey, IEnumerable<TInput>>>
@@ -86,7 +86,7 @@ namespace ZeroLevel.Services.PartitionStorage
                         }
                     }
                     // compress new file
-                    (_temporaryAccessor as StorePartitionAccessor<TKey, TInput, TValue, TMeta>)
+                    (_temporaryAccessor as StorePartitionBuilder<TKey, TInput, TValue, TMeta>)
                             .CompressFile(file);
                     
                     // replace old file by new
@@ -98,16 +98,6 @@ namespace ZeroLevel.Services.PartitionStorage
             Directory.Delete(_temporaryAccessor.GetCatalogPath(), true);
         }
 
-        public StorePartitionKeyValueSearchResult<TKey, TValue> Find(TKey key)
-            => _accessor.Find(key);
-
-        public IEnumerable<StorePartitionKeyValueSearchResult<TKey, TValue>> Find(IEnumerable<TKey> keys)
-            => _accessor.Find(keys);
-        public IEnumerable<StorePartitionKeyValueSearchResult<TKey, TValue>> Iterate()
-            => _accessor.Iterate();
-        public IEnumerable<StorePartitionKeyValueSearchResult<TKey, TValue>> IterateKeyBacket(TKey key)
-            => _accessor.IterateKeyBacket(key);
-
         /// <summary>
         /// Deletes only new entries. Existing entries remain unchanged.
         /// </summary>
diff --git a/ZeroLevel/Services/PartitionStorage/StorePartitionAccessor.cs b/ZeroLevel/Services/PartitionStorage/Partition/StorePartitionAccessor.cs
similarity index 74%
rename from ZeroLevel/Services/PartitionStorage/StorePartitionAccessor.cs
rename to ZeroLevel/Services/PartitionStorage/Partition/StorePartitionAccessor.cs
index aa8db87..e6da0b8 100644
--- a/ZeroLevel/Services/PartitionStorage/StorePartitionAccessor.cs
+++ b/ZeroLevel/Services/PartitionStorage/Partition/StorePartitionAccessor.cs
@@ -1,9 +1,7 @@
 using System;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Threading.Tasks;
 using ZeroLevel.Services.FileSystem;
 using ZeroLevel.Services.Serialization;
 
@@ -12,30 +10,23 @@ namespace ZeroLevel.Services.PartitionStorage
     public class StorePartitionAccessor<TKey, TInput, TValue, TMeta>
         : IStorePartitionAccessor<TKey, TInput, TValue>
     {
-        private readonly ConcurrentDictionary<string, MemoryStreamWriter> _writeStreams
-            = new ConcurrentDictionary<string, MemoryStreamWriter>();
-        private readonly IStoreOptions<TKey, TInput, TValue, TMeta> _options;
+        private readonly StoreOptions<TKey, TInput, TValue, TMeta> _options;
         private readonly string _catalog;
         private readonly TMeta _info;
 
         public string Catalog { get { return _catalog; } }
-        public StorePartitionAccessor(IStoreOptions<TKey, TInput, TValue, TMeta> options, TMeta info)
+        public StorePartitionAccessor(StoreOptions<TKey, TInput, TValue, TMeta> options, TMeta info)
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
             _info = info;
             _options = options;
             _catalog = _options.GetCatalogPath(info);
-            if (Directory.Exists(_catalog) == false)
-            {
-                Directory.CreateDirectory(_catalog);
-            }
         }
 
         public int CountDataFiles() => Directory.GetFiles(_catalog)?.Length ?? 0;
         public string GetCatalogPath() => _catalog;
         public void DropData() => FSUtils.CleanAndTestFolder(_catalog);
 
-        #region API !only after data compression!
         public StorePartitionKeyValueSearchResult<TKey, TValue> Find(TKey key)
         {
             var fileName = _options.GetFileName(key, _info);
@@ -44,7 +35,7 @@ namespace ZeroLevel.Services.PartitionStorage
                 long startOffset = 0;
                 if (_options.Index.Enabled)
                 {
-                    var index = new StorePartitionIndex<TKey, TMeta>(_catalog, _info, _options.FilePartition, _options.KeyComparer);
+                    var index = new StorePartitionSparseIndex<TKey, TMeta>(_catalog, _info, _options.FilePartition, _options.KeyComparer);
                     var offset = index.GetOffset(key);
                     startOffset = offset.Offset;
                 }
@@ -171,35 +162,6 @@ namespace ZeroLevel.Services.PartitionStorage
                 }
             }
         }
-        #endregion
-
-
-        #region API !only before data compression!
-        public void Store(TKey key, TInput value)
-        {
-            var fileName = _options.GetFileName(key, _info);
-            var stream = GetWriteStream(fileName);
-            stream.SerializeCompatible(key);
-            stream.SerializeCompatible(value);
-        }
-        public void CompleteAddingAndCompress()
-        {
-            // Close all write streams
-            foreach (var s in _writeStreams)
-            {
-                try
-                {
-                    s.Value.Dispose();
-                }
-                catch { }
-            }
-            var files = Directory.GetFiles(_catalog);
-            if (files != null && files.Length > 1)
-            {
-                Parallel.ForEach(files, file => CompressFile(file));
-            }
-        }
-        #endregion
 
         #region Private methods
         private IEnumerable<StorePartitionKeyValueSearchResult<TKey, TValue>> Find(string fileName,
@@ -209,7 +171,7 @@ namespace ZeroLevel.Services.PartitionStorage
             {
                 if (_options.Index.Enabled)
                 {
-                    var index = new StorePartitionIndex<TKey, TMeta>(_catalog, _info, _options.FilePartition, _options.KeyComparer);
+                    var index = new StorePartitionSparseIndex<TKey, TMeta>(_catalog, _info, _options.FilePartition, _options.KeyComparer);
                     var offsets = index.GetOffset(keys, true);
                     using (var reader = GetReadStream(fileName))
                     {
@@ -278,46 +240,7 @@ namespace ZeroLevel.Services.PartitionStorage
                 }
             }
         }
-        internal void CompressFile(string file)
-        {
-            var dict = new Dictionary<TKey, HashSet<TInput>>();
-            using (var reader = new MemoryStreamReader(new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.None, 4096 * 1024)))
-            {
-                while (reader.EOS == false)
-                {
-                    TKey k = reader.ReadCompatible<TKey>();
-                    TInput v = reader.ReadCompatible<TInput>();
-                    if (false == dict.ContainsKey(k))
-                    {
-                        dict[k] = new HashSet<TInput>();
-                    }
-                    dict[k].Add(v);
-                }
-            }
-            var tempPath = Path.GetTempPath();
-            var tempFile = Path.Combine(tempPath, Path.GetTempFileName());
-            using (var writer = new MemoryStreamWriter(new FileStream(tempFile, FileMode.Create, FileAccess.Write, FileShare.None, 4096 * 1024)))
-            {
-                // sort for search acceleration
-                foreach (var pair in dict.OrderBy(p => p.Key))
-                {
-                    var v = _options.MergeFunction(pair.Value);
-                    writer.SerializeCompatible(pair.Key);
-                    writer.SerializeCompatible(v);
-                }
-            }
-            File.Delete(file);
-            File.Move(tempFile, file, true);
-        }        
-        private MemoryStreamWriter GetWriteStream(string fileName)
-        {
-            return _writeStreams.GetOrAdd(fileName, k =>
-            {
-                var filePath = Path.Combine(_catalog, k);
-                var stream = new FileStream(filePath, FileMode.Append, FileAccess.Write, FileShare.None, 4096 * 1024);
-                return new MemoryStreamWriter(stream);
-            });
-        }
+      
         private MemoryStreamReader GetReadStream(string fileName)
         {
             var filePath = Path.Combine(_catalog, fileName);
@@ -328,7 +251,5 @@ namespace ZeroLevel.Services.PartitionStorage
         public void Dispose()
         {
         }
-
-
     }
 }
diff --git a/ZeroLevel/Services/PartitionStorage/Partition/StorePartitionBuilder.cs b/ZeroLevel/Services/PartitionStorage/Partition/StorePartitionBuilder.cs
new file mode 100644
index 0000000..9323aec
--- /dev/null
+++ b/ZeroLevel/Services/PartitionStorage/Partition/StorePartitionBuilder.cs
@@ -0,0 +1,160 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using ZeroLevel.Services.FileSystem;
+using ZeroLevel.Services.Serialization;
+
+namespace ZeroLevel.Services.PartitionStorage
+{
+    public class StorePartitionBuilder<TKey, TInput, TValue, TMeta>
+        : IStorePartitionBuilder<TKey, TInput, TValue>
+    {
+        private readonly ConcurrentDictionary<string, MemoryStreamWriter> _writeStreams
+            = new ConcurrentDictionary<string, MemoryStreamWriter>();
+        private readonly StoreOptions<TKey, TInput, TValue, TMeta> _options;
+        private readonly string _catalog;
+        private readonly TMeta _info;
+
+        public string Catalog { get { return _catalog; } }
+        public StorePartitionBuilder(StoreOptions<TKey, TInput, TValue, TMeta> options, TMeta info)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+            _info = info;
+            _options = options;
+            _catalog = _options.GetCatalogPath(info);
+            if (Directory.Exists(_catalog) == false)
+            {
+                Directory.CreateDirectory(_catalog);
+            }
+        }
+
+        public int CountDataFiles() => Directory.GetFiles(_catalog)?.Length ?? 0;
+        public string GetCatalogPath() => _catalog;
+        public void DropData() => FSUtils.CleanAndTestFolder(_catalog);
+
+        public void Store(TKey key, TInput value)
+        {
+            var fileName = _options.GetFileName(key, _info);
+            var stream = GetWriteStream(fileName);
+            stream.SerializeCompatible(key);
+            stream.SerializeCompatible(value);
+        }
+        public void CompleteAddingAndCompress()
+        {
+            // Close all write streams
+            foreach (var s in _writeStreams)
+            {
+                try
+                {
+                    s.Value.Dispose();
+                }
+                catch { }
+            }
+            var files = Directory.GetFiles(_catalog);
+            if (files != null && files.Length > 1)
+            {
+                Parallel.ForEach(files, file => CompressFile(file));
+            }
+        }
+        public void RebuildIndex()
+        {
+            if (_options.Index.Enabled)
+            {
+                var indexFolder = Path.Combine(_catalog, "__indexes__");
+                FSUtils.CleanAndTestFolder(indexFolder);
+                var files = Directory.GetFiles(_catalog);
+                if (files != null && files.Length > 1)
+                {
+                    var dict = new Dictionary<TKey, long>();
+                    foreach (var file in files)
+                    {
+                        dict.Clear();
+                        using (var reader = GetReadStream(Path.GetFileName(file)))
+                        {
+                            while (reader.EOS == false)
+                            {
+                                var pos = reader.Stream.Position;
+                                var k = reader.ReadCompatible<TKey>();
+                                dict[k] = pos;
+                                reader.ReadCompatible<TValue>();
+                            }
+                        }
+                        if (dict.Count > _options.Index.FileIndexCount * 8)
+                        {
+                            var step = (int)Math.Round(((float)dict.Count / (float)_options.Index.FileIndexCount), MidpointRounding.ToZero);
+                            var index_file = Path.Combine(indexFolder, Path.GetFileName(file));
+                            var d_arr = dict.OrderBy(p => p.Key).ToArray();
+                            using (var writer = new MemoryStreamWriter(
+                                new FileStream(index_file, FileMode.Create, FileAccess.Write, FileShare.None)))
+                            {
+                                for (int i = 0; i < _options.Index.FileIndexCount; i++)
+                                {
+                                    var pair = d_arr[i * step];
+                                    writer.WriteCompatible(pair.Key);
+                                    writer.WriteLong(pair.Value);
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        #region Private methods
+        internal void CompressFile(string file)
+        {
+            var dict = new Dictionary<TKey, HashSet<TInput>>();
+            using (var reader = new MemoryStreamReader(new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.None, 4096 * 1024)))
+            {
+                while (reader.EOS == false)
+                {
+                    TKey k = reader.ReadCompatible<TKey>();
+                    TInput v = reader.ReadCompatible<TInput>();
+                    if (false == dict.ContainsKey(k))
+                    {
+                        dict[k] = new HashSet<TInput>();
+                    }
+                    dict[k].Add(v);
+                }
+            }
+            var tempPath = Path.GetTempPath();
+            var tempFile = Path.Combine(tempPath, Path.GetTempFileName());
+            using (var writer = new MemoryStreamWriter(new FileStream(tempFile, FileMode.Create, FileAccess.Write, FileShare.None, 4096 * 1024)))
+            {
+                // sort for search acceleration
+                foreach (var pair in dict.OrderBy(p => p.Key))
+                {
+                    var v = _options.MergeFunction(pair.Value);
+                    writer.SerializeCompatible(pair.Key);
+                    writer.SerializeCompatible(v);
+                }
+            }
+            File.Delete(file);
+            File.Move(tempFile, file, true);
+        }
+        private MemoryStreamWriter GetWriteStream(string fileName)
+        {
+            return _writeStreams.GetOrAdd(fileName, k =>
+            {
+                var filePath = Path.Combine(_catalog, k);
+                var stream = new FileStream(filePath, FileMode.Append, FileAccess.Write, FileShare.None, 4096 * 1024);
+                return new MemoryStreamWriter(stream);
+            });
+        }
+        private MemoryStreamReader GetReadStream(string fileName)
+        {
+            var filePath = Path.Combine(_catalog, fileName);
+            var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite, 4096 * 1024);
+            return new MemoryStreamReader(stream);
+        }
+        #endregion
+        public void Dispose()
+        {
+        }
+
+
+    }
+}
diff --git a/ZeroLevel/Services/PartitionStorage/Search/PartitionSearchRequest.cs b/ZeroLevel/Services/PartitionStorage/Search/PartitionSearchRequest.cs
new file mode 100644
index 0000000..74dafb4
--- /dev/null
+++ b/ZeroLevel/Services/PartitionStorage/Search/PartitionSearchRequest.cs
@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+
+namespace ZeroLevel.Services.PartitionStorage
+{
+    public class PartitionSearchRequest<TKey, TMeta>
+    {
+        public TMeta Info { get; set; }
+        public IEnumerable<TKey> Keys { get; set; }
+    }
+}
diff --git a/ZeroLevel/Services/PartitionStorage/StorePartitionKeyValueSearchResult.cs b/ZeroLevel/Services/PartitionStorage/Search/StorePartitionKeyValueSearchResult.cs
similarity index 100%
rename from ZeroLevel/Services/PartitionStorage/StorePartitionKeyValueSearchResult.cs
rename to ZeroLevel/Services/PartitionStorage/Search/StorePartitionKeyValueSearchResult.cs
diff --git a/ZeroLevel/Services/PartitionStorage/StoreSearchRequest.cs b/ZeroLevel/Services/PartitionStorage/Search/StoreSearchRequest.cs
similarity index 61%
rename from ZeroLevel/Services/PartitionStorage/StoreSearchRequest.cs
rename to ZeroLevel/Services/PartitionStorage/Search/StoreSearchRequest.cs
index efa5935..8753085 100644
--- a/ZeroLevel/Services/PartitionStorage/StoreSearchRequest.cs
+++ b/ZeroLevel/Services/PartitionStorage/Search/StoreSearchRequest.cs
@@ -2,11 +2,6 @@
 
 namespace ZeroLevel.Services.PartitionStorage
 {
-    public class PartitionSearchRequest<TKey, TMeta>
-    {
-        public TMeta Info { get; set; }
-        public IEnumerable<TKey> Keys { get; set; }
-    }
     public class StoreSearchRequest<TKey, TMeta>
     {
         public IEnumerable<PartitionSearchRequest<TKey, TMeta>> PartitionSearchRequests { get; set; }
diff --git a/ZeroLevel/Services/PartitionStorage/StoreSearchResult.cs b/ZeroLevel/Services/PartitionStorage/Search/StoreSearchResult.cs
similarity index 100%
rename from ZeroLevel/Services/PartitionStorage/StoreSearchResult.cs
rename to ZeroLevel/Services/PartitionStorage/Search/StoreSearchResult.cs
diff --git a/ZeroLevel/Services/PartitionStorage/Store.cs b/ZeroLevel/Services/PartitionStorage/Store.cs
index 58aadbb..9bc6494 100644
--- a/ZeroLevel/Services/PartitionStorage/Store.cs
+++ b/ZeroLevel/Services/PartitionStorage/Store.cs
@@ -10,8 +10,8 @@ namespace ZeroLevel.Services.PartitionStorage
     public class Store<TKey, TInput, TValue, TMeta> :
         IStore<TKey, TInput, TValue, TMeta>
     {
-        private readonly IStoreOptions<TKey, TInput, TValue, TMeta> _options;
-        public Store(IStoreOptions<TKey, TInput, TValue, TMeta> options)
+        private readonly StoreOptions<TKey, TInput, TValue, TMeta> _options;
+        public Store(StoreOptions<TKey, TInput, TValue, TMeta> options)
         {
             if (options == null) throw new ArgumentNullException(nameof(options));
             _options = options;
@@ -26,8 +26,12 @@ namespace ZeroLevel.Services.PartitionStorage
             return new StorePartitionAccessor<TKey, TInput, TValue, TMeta>(_options, info);
         }
 
-        public IStorePartitionAccessor<TKey, TInput, TValue> CreateMergeAccessor(TMeta info
-            , Func<TValue, IEnumerable<TInput>> decompressor)
+        public IStorePartitionBuilder<TKey, TInput, TValue> CreateBuilder(TMeta info)
+        {
+             return new StorePartitionBuilder<TKey, TInput, TValue, TMeta>(_options, info);
+        }
+
+        public IStorePartitionBuilder<TKey, TInput, TValue> CreateMergeAccessor(TMeta info, Func<TValue, IEnumerable<TInput>> decompressor)
         {
             return new StoreMergePartitionAccessor<TKey, TInput, TValue, TMeta>(_options, info, decompressor);
         }