diff --git a/bigfile/__init__.py b/bigfile/__init__.py
index 8d07f5a..fb141cb 100644
--- a/bigfile/__init__.py
+++ b/bigfile/__init__.py
@@ -5,6 +5,8 @@
 from .pyxbigfile import ColumnLowLevelAPI
 from .pyxbigfile import FileLowLevelAPI
 from .pyxbigfile import set_buffer_size
+from . import pyxbigfile
+from functools import wraps
 
 import os
 import numpy
@@ -243,6 +245,10 @@ def create(self, f, blockname, dtype=None, size=None, Nfile=1):
             super(ColumnMPI, self).close()
         return self.open(f, blockname)
 
+    @_enhance_getslice
+    def __getitem__(self, index):
+        return Column.__getitem__(self, index)
+
     def open(self, f, blockname):
         if not check_unique(blockname, self.comm):
             raise BigFileError("blockname is inconsistent between ranks")
@@ -429,9 +435,6 @@ def __getitem__(self, sl):
         elif isstrlist(sl):
             assert all([(col in self.dtype.names) for col in sl])
             return type(self)(self.file, sl)
-        elif numpy.isscalar(sl):
-            sl = slice(sl, sl + 1)
-            return self[sl][0]
         else:
             return self._getslice(sl)
 
diff --git a/bigfile/pyxbigfile.pyx b/bigfile/pyxbigfile.pyx
index fca04ea..9d6add7 100644
--- a/bigfile/pyxbigfile.pyx
+++ b/bigfile/pyxbigfile.pyx
@@ -21,7 +21,7 @@ except NameError:
         return isinstance(s, str)
 
 
-cdef extern from "bigfile.c":
+cdef extern from "bigfile.h":
     ctypedef void * CBigFileStream "BigFileStream"
 
     struct CBigFileMethods "BigFileMethods":
@@ -784,3 +784,93 @@ cdef class ColumnLowLevelAPI:
         except:
             return "<CBigBlock is invalid>"
         
+
+cdef class Dataset:
+    cdef CBigRecordType rtype
+    cdef readonly FileLowLevelAPI file
+    cdef readonly size_t size
+    cdef readonly tuple shape
+    cdef readonly numpy.dtype dtype
+
+    def __init__(self, file, dtype, size):
+        self.file = file
+        self.rtype.nfield = 0
+        big_record_type_clear(&self.rtype)
+        fields = []
+
+        for i, name in enumerate(dtype.names):
+            basedtype = dtype[name].base.str.encode()
+            nmemb = int(numpy.prod(dtype[name].shape))
+
+            big_record_type_set(&self.rtype, i,
+                name.encode(),
+                basedtype,
+                nmemb,
+            )
+        big_record_type_complete(&self.rtype)
+
+        self.size = size
+        self.ndim = 1
+        self.shape = (size, )
+
+        dtype = []
+        # No need to use offset, because numpy is also
+        # compactly packed
+        for i in range(self.rtype.nfield):
+            if self.rtype.fields[i].nmemb == 1:
+                shape = 1
+            else:
+                shape = (self.rtype.fields[i].nmemb, )
+            dtype.append((
+                self.rtype.fields[i].name.decode(),
+                self.rtype.fields[i].dtype,
+                shape)
+            )
+        self.dtype = numpy.dtype(dtype, align=False)
+        assert self.dtype.itemsize == self.rtype.itemsize
+
+    def read(self, numpy.intp_t start, numpy.intp_t length, numpy.ndarray out=None):
+        if out is None:
+            out = numpy.empty(length, self.dtype)
+        with nogil:
+            rt = big_file_read_records(&self.file.bf, &self.rtype, start, length, out.data)
+        if rt != 0:
+            raise Error()
+        return out
+
+    def _create_records(self, numpy.intp_t size, numpy.intp_t Nfile=1, char * mode=b"w+"):
+        """ mode can be a+ or w+."""
+        cdef numpy.ndarray fsize
+
+        if Nfile < 0:
+            raise ValueError("Cannot create negative number of files.")
+        if Nfile == 0 and size != 0:
+            raise ValueError("Cannot create zero files for non-zero number of items.")
+
+        fsize = numpy.empty(dtype='intp', shape=Nfile)
+        fsize[:] = (numpy.arange(Nfile) + 1) * size // Nfile \
+                 - (numpy.arange(Nfile)) * size // Nfile
+
+        with nogil:
+            rt = big_file_create_records(&self.file.bf, &self.rtype, mode, Nfile, <size_t*>fsize.data)
+        if rt != 0:
+            raise Error()
+        self.size = self.size + size
+
+    def append(self, numpy.ndarray buf, numpy.intp_t Nfile=1):
+        assert buf.dtype == self.dtype
+        assert buf.ndim == 1
+        tail = self.size
+        self._create_records(len(buf), Nfile=Nfile, mode=b"a+")
+        self.write(tail, buf)
+
+    def write(self, numpy.intp_t start, numpy.ndarray buf):
+        assert buf.dtype == self.dtype
+        assert buf.ndim == 1
+        with nogil:
+            rt = big_file_write_records(&self.file.bf, &self.rtype, start, buf.shape[0], buf.data)
+        if rt != 0:
+            raise Error()
+
+    def __dealloc__(self):
+        big_record_type_clear(&self.rtype)
diff --git a/bigfile/tests/test_bigfile.py b/bigfile/tests/test_bigfile.py
index 4bf7873..0a8cceb 100644
--- a/bigfile/tests/test_bigfile.py
+++ b/bigfile/tests/test_bigfile.py
@@ -395,7 +395,7 @@ def test_mpi_attr(comm):
 
 def test_version():
     import bigfile
-    assert hasattr(File, '__version__')
+    assert hasattr(bigfile, '__version__')
 
 @MPITest(commsize=[1, 4])
 def test_mpi_large(comm):
diff --git a/src/bigfile-mpi.c b/src/bigfile-mpi.c
index 4cf57db..2920895 100644
--- a/src/bigfile-mpi.c
+++ b/src/bigfile-mpi.c
@@ -206,12 +206,12 @@ _big_block_mpi_create(BigBlock * bb,
 
     int i;
     for(i = (size_t) bb->Nfile * rank / NTask; i < (size_t) bb->Nfile * (rank + 1) / NTask; i ++) {
-        FILE * fp = _big_file_open_a_file(bb->methods, bb->basename, i, "w", 1);
+        BigFileStream fp = _big_file_open_a_file(bb->methods, bb->basename, i, "w", 1);
         if(fp == NULL) {
             rt = -1;
             break;
         }
-        fclose(fp);
+        bb->methods->fclose(fp);
     }
 
     BCAST_AND_RAISEIF(rt, comm);
@@ -251,12 +251,12 @@ int big_block_mpi_grow(BigBlock * bb,
 
     int i;
     for(i = (size_t) Nfile_grow * rank / NTask; i < (size_t) Nfile_grow * (rank + 1) / NTask; i ++) {
-        FILE * fp = _big_file_open_a_file(bb->methods, bb->basename, i + oldNfile, "w", 1);
+        BigFileStream fp = _big_file_open_a_file(bb->methods, bb->basename, i + oldNfile, "w", 1);
         if(fp == NULL) {
             rt = -1;
             break;
         }
-        fclose(fp);
+        bb->methods->fclose(fp);
     }
 
     BCAST_AND_RAISEIF(rt, comm);
diff --git a/src/bigfile.c b/src/bigfile.c
index e999777..150c3d5 100644
--- a/src/bigfile.c
+++ b/src/bigfile.c
@@ -638,6 +638,7 @@ _big_block_grow_internal(BigBlock * bb, int Nfile_grow, const size_t fsize_grow[
     bb->fchecksum = fchecksum;
     bb->Nfile = Nfile;
     bb->size = bb->foffset[Nfile];
+    bb->dirty = 1;
 
     return 0;
 }