diff --git a/hail/python/hail/backend/backend.py b/hail/python/hail/backend/backend.py
index 7240a7283be..d9873a69b04 100644
--- a/hail/python/hail/backend/backend.py
+++ b/hail/python/hail/backend/backend.py
@@ -9,7 +9,7 @@
 
 class Backend(object):
     @abc.abstractmethod
-    def interpret(self, ir):
+    def execute(self, ir):
         return
 
     @abc.abstractmethod
@@ -30,7 +30,7 @@ def _to_java_ir(self, ir):
             ir._jir = ir.parse(code, ir_map=r.jirs)
         return ir._jir
 
-    def interpret(self, ir):
+    def execute(self, ir):
         return ir.typ._from_json(
             Env.hail().expr.ir.Interpret.interpretJSON(
                 self._to_java_ir(ir)))
@@ -50,7 +50,7 @@ def __init__(self, host, port=80, scheme='http'):
         self.host = host
         self.port = port
 
-    def interpret(self, ir):
+    def execute(self, ir):
         r = Renderer(stop_at_jir=True)
         code = r(ir)
         assert len(r.jirs) == 0
diff --git a/hail/python/hail/expr/expressions/expression_utils.py b/hail/python/hail/expr/expressions/expression_utils.py
index 677cfc2a7ae..34e0a2c2ec5 100644
--- a/hail/python/hail/expr/expressions/expression_utils.py
+++ b/hail/python/hail/expr/expressions/expression_utils.py
@@ -190,7 +190,7 @@ def eval_typed(expression):
     analyze('eval_typed', expression, Indices(expression._indices.source))
 
     if expression._indices.source is None:
-        return (Env.hc()._backend.interpret(expression._ir), expression.dtype)
+        return (Env.backend().execute(expression._ir), expression.dtype)
     else:
         return expression.collect()[0], expression.dtype
 
diff --git a/hail/python/hail/ir/ir.py b/hail/python/hail/ir/ir.py
index 20bcf79980a..9ce3b5a912a 100644
--- a/hail/python/hail/ir/ir.py
+++ b/hail/python/hail/ir/ir.py
@@ -1291,9 +1291,9 @@ def __eq__(self, other):
 class TableExport(IR):
     @typecheck_method(child=TableIR,
                       path=str,
-                      types_file=str,
+                      types_file=nullable(str),
                       header=bool,
-                      export_type=hail_type)
+                      export_type=int)
     def __init__(self, child, path, types_file, header, export_type):
         super().__init__(child)
         self.child = child
@@ -1308,12 +1308,12 @@ def copy(self, child):
         return new_instance(child, self.path, self.types_file, self.header, self.export_type)
 
     def render(self, r):
-        return '(TableExport "{}" "{}" "{}" {} {})'.format(
+        return '(TableExport {} "{}" "{}" {} {})'.format(
+            r(self.child),
             escape_str(self.path),
-            escape_str(self.types_file),
-            escape_str(self.header),
-            self.export_type,
-            r(self.child))
+            escape_str(self.types_file) if self.types_file else 'None',
+            self.header,
+            self.export_type)
 
     def __eq__(self, other):
         return isinstance(other, TableExport) and \
diff --git a/hail/python/hail/ir/table_ir.py b/hail/python/hail/ir/table_ir.py
index a176020e1e8..a86f14cfa15 100644
--- a/hail/python/hail/ir/table_ir.py
+++ b/hail/python/hail/ir/table_ir.py
@@ -25,6 +25,15 @@ def render(self, r):
         return '(TableJoin {} {} {} {})'.format(
             escape_id(self.join_type), self.join_key, r(self.left), r(self.right))
 
+class TableLeftJoinRightDistinct(TableIR):
+    def __init__(self, left, right, root):
+        self.left = left
+        self.right = right
+        self.root = root
+
+    def render(self, r):
+        return '(TableLeftJoinRightDistinct {} {} {})'.format(
+            escape_id(self.root), r(self.left), r(self.right))
 
 class TableUnion(TableIR):
     def __init__(self, children):
diff --git a/hail/python/hail/matrixtable.py b/hail/python/hail/matrixtable.py
index 9175fd3db50..7916c0756e7 100644
--- a/hail/python/hail/matrixtable.py
+++ b/hail/python/hail/matrixtable.py
@@ -1688,7 +1688,7 @@ def aggregate_rows(self, expr) -> Any:
         base, _ = self._process_joins(expr)
         analyze('MatrixTable.aggregate_rows', expr, self._global_indices, {self._row_axis})
         subst_query = subst(expr._ir, {}, {'va': Ref('row')})
-        return Env.hc()._backend.interpret(TableAggregate(MatrixRowsTable(base._mir), subst_query))
+        return Env.backend().execute(TableAggregate(MatrixRowsTable(base._mir), subst_query))
 
     @typecheck_method(expr=expr_any)
     def aggregate_cols(self, expr) -> Any:
@@ -1733,7 +1733,7 @@ def aggregate_cols(self, expr) -> Any:
         base, _ = self._process_joins(expr)
         analyze('MatrixTable.aggregate_cols', expr, self._global_indices, {self._col_axis})
         subst_query = subst(expr._ir, {}, {'sa': Ref('row')})
-        return Env.hc()._backend.interpret(TableAggregate(MatrixColsTable(base._mir), subst_query))
+        return Env.backend().execute(TableAggregate(MatrixColsTable(base._mir), subst_query))
 
     @typecheck_method(expr=expr_any)
     def aggregate_entries(self, expr) -> Any:
@@ -1773,7 +1773,7 @@ def aggregate_entries(self, expr) -> Any:
 
         base, _ = self._process_joins(expr)
         analyze('MatrixTable.aggregate_entries', expr, self._global_indices, {self._row_axis, self._col_axis})
-        return Env.hc()._backend.interpret(MatrixAggregate(base._mir, expr._ir))
+        return Env.backend().execute(MatrixAggregate(base._mir, expr._ir))
 
     @typecheck_method(field_expr=oneof(str, Expression))
     def explode_rows(self, field_expr) -> 'MatrixTable':
@@ -2088,7 +2088,7 @@ def count_rows(self) -> int:
             Number of rows in the matrix.
         """
 
-        return Env.hc()._backend.interpret(
+        return Env.backend().execute(
             TableCount(MatrixRowsTable(self._mir)))
 
     def _force_count_rows(self):
@@ -2113,7 +2113,7 @@ def count_cols(self) -> int:
             Number of columns in the matrix.
         """
 
-        return Env.hc()._backend.interpret(
+        return Env.backend().execute(
             TableCount(MatrixColsTable(self._mir)))
 
     def count(self) -> Tuple[int, int]:
@@ -2160,7 +2160,7 @@ def write(self, output: str, overwrite: bool = False, stage_locally: bool = Fals
         """
 
         writer = MatrixNativeWriter(output, overwrite, stage_locally, _codec_spec)
-        Env.hc()._backend.interpret(MatrixWrite(self._mir, writer))
+        Env.backend().execute(MatrixWrite(self._mir, writer))
 
     def globals_table(self) -> Table:
         """Returns a table with a single row with the globals of the matrix table.
diff --git a/hail/python/hail/methods/impex.py b/hail/python/hail/methods/impex.py
index 87fb6f77968..50af4850546 100644
--- a/hail/python/hail/methods/impex.py
+++ b/hail/python/hail/methods/impex.py
@@ -160,7 +160,7 @@ def export_gen(dataset, output, precision=4, gp=None, id1=None, id2=None,
                                   entry_exprs=entry_exprs)
 
     writer = MatrixGENWriter(output, precision)
-    Env.hc()._backend.interpret(MatrixWrite(dataset._mir, writer))
+    Env.backend().execute(MatrixWrite(dataset._mir, writer))
 
 
 @typecheck(dataset=MatrixTable,
@@ -301,7 +301,7 @@ def export_plink(dataset, output, call=None, fam_id=None, ind_id=None, pat_id=No
         raise TypeError("\n".join(errors))
 
     writer = MatrixPLINKWriter(output)
-    Env.hc()._backend.interpret(MatrixWrite(dataset._mir, writer))
+    Env.backend().execute(MatrixWrite(dataset._mir, writer))
 
 
 @typecheck(dataset=MatrixTable,
@@ -418,7 +418,7 @@ def export_vcf(dataset, output, append_to_header=None, parallel=None, metadata=N
                              append_to_header,
                              Env.hail().utils.ExportType.getExportType(parallel),
                              metadata)
-    Env.hc()._backend.interpret(MatrixWrite(dataset._mir, writer))
+    Env.backend().execute(MatrixWrite(dataset._mir, writer))
 
 
 @typecheck(path=str,
diff --git a/hail/python/hail/table.py b/hail/python/hail/table.py
index e916c44a6ef..400dec28946 100644
--- a/hail/python/hail/table.py
+++ b/hail/python/hail/table.py
@@ -411,7 +411,7 @@ def count(self):
         -------
         :obj:`int`
         """
-        return Env.hc()._backend.interpret(TableCount(self._tir))
+        return Env.backend().execute(TableCount(self._tir))
 
     def _force_count(self):
         return self._jt.forceCount()
@@ -996,7 +996,8 @@ def export(self, output, types_file=None, header=True, parallel=None):
             the export will be slower.
         """
 
-        self._jt.export(output, types_file, header, Env.hail().utils.ExportType.getExportType(parallel))
+        Env.backend().execute(
+            TableExport(self._tir, output, types_file, header, Env.hail().utils.ExportType.getExportType(parallel)))
 
     def group_by(self, *exprs, **named_exprs) -> 'GroupedTable':
         """Group by a new key for use with :meth:`.GroupedTable.aggregate`.
@@ -1135,7 +1136,7 @@ def aggregate(self, expr):
         base, _ = self._process_joins(expr)
         analyze('Table.aggregate', expr, self._global_indices, {self._row_axis})
 
-        return Env.hc()._backend.interpret(TableAggregate(base._tir, expr._ir))
+        return Env.backend().execute(TableAggregate(base._tir, expr._ir))
 
     @typecheck_method(output=str,
                       overwrite=bool,
@@ -1165,7 +1166,7 @@ def write(self, output: str, overwrite = False, stage_locally: bool = False,
             If ``True``, overwrite an existing file at the destination.
         """
 
-        Env.hc()._backend.interpret(TableWrite(self._tir, output, overwrite, stage_locally, _codec_spec))
+        Env.backend().execute(TableWrite(self._tir, output, overwrite, stage_locally, _codec_spec))
 
     @typecheck_method(n=int, width=int, truncate=nullable(int), types=bool, handler=anyfunc)
     def show(self, n=10, width=90, truncate=None, types=True, handler=print):
@@ -1341,10 +1342,11 @@ def types_compatible(left, right):
             def joiner(left):
                 if not is_key:
                     original_key = list(left.key)
-                    left = Table._from_java(left.key_by()._jt.mapRows(str(Apply('annotate',
-                                                             left._row._ir,
-                                                             hl.struct(**dict(zip(uids, exprs)))._ir)))
-                                 ).key_by(*uids)
+                    left = Table(TableMapRows(left.key_by()._tir,
+                                              Apply('annotate',
+                                                    left._row._ir,
+                                                    hl.struct(**dict(zip(uids, exprs)))._ir))
+                           ).key_by(*uids)
                     rekey_f = lambda t: t.key_by(*original_key)
                 else:
                     rekey_f = identity
@@ -1352,7 +1354,7 @@ def joiner(left):
                 if is_interval:
                     left = Table._from_java(left._jt.intervalJoin(self._jt, uid))
                 else:
-                    left = Table._from_java(left._jt.leftJoinRightDistinct(self._jt, uid))
+                    left = Table(TableLeftJoinRightDistinct(left._tir, self._tir, uid))
                 return rekey_f(left)
 
             all_uids.append(uid)
@@ -1387,7 +1389,8 @@ def joiner(left):
                     key = None
                 else:
                     key = [str(k._ir) for k in exprs]
-                joiner = lambda left: MatrixTable._from_java(left._jmt.annotateRowsTableIR(right._jt, uid, key))
+                joiner = lambda left: MatrixTable(MatrixAnnotateRowsTable(
+                    left._mir, right._tir, uid, key))
                 ast = Join(GetField(TopLevelReference('va'), uid),
                            [uid],
                            exprs,
@@ -1399,7 +1402,7 @@ def joiner(left):
                         exprs[i] is src.col_key[i] for i in range(len(exprs))]):
                     # key is already correct
                     def joiner(left):
-                        return MatrixTable._from_java(left._jmt.annotateColsTable(right._jt, uid))
+                        return MatrixTable(MatrixAnnotateColsTable(left._mir, right._tir, uid))
                 else:
                     index_uid = Env.get_uid()
                     uids = [Env.get_uid() for _ in exprs]
@@ -1417,10 +1420,12 @@ def joiner(left: MatrixTable):
                                   .join(self, 'inner')
                                   .key_by(index_uid)
                                   .drop(*uids))
-                        result = MatrixTable._from_java(left.add_col_index(index_uid)
-                                                        .key_cols_by(index_uid)
-                                                        ._jmt
-                                                        .annotateColsTable(joined._jt, uid)).key_cols_by(*prev_key)
+                        result = MatrixTable(MatrixAnnotateColsTable(
+                            (left.add_col_index(index_uid)
+                             .key_cols_by(index_uid)
+                             ._mir),
+                            joined._tir,
+                            uid)).key_cols_by(*prev_key)
                         return result
                 ir = Join(GetField(TopLevelReference('sa'), uid),
                           all_uids,
@@ -2318,11 +2323,8 @@ def to_matrix_table(self, row_key, col_key, row_fields=[], col_fields=[], n_part
         if len(col_key) == 0:
             raise ValueError(f"'to_matrix_table': require at least one col key field")
 
-        return hl.MatrixTable._from_java(self._jt.jToMatrixTable(row_key,
-                                                                 col_key,
-                                                                 row_fields,
-                                                                 col_fields,
-                                                                 n_partitions))
+        return hl.MatrixTable(TableToMatrixTable(
+            self._tir, row_key, col_key, row_fields, col_fields, n_partitions))
 
     @property
     def globals(self) -> 'StructExpression':
@@ -2617,8 +2619,8 @@ def _filter_partitions(self, parts, keep=True):
                       entries_field_name=str,
                       col_key=sequenceof(str))
     def _unlocalize_entries(self, entries_field_name, cols_field_name, col_key):
-        return hl.MatrixTable._from_java(
-                self._jt.unlocalizeEntries(entries_field_name, cols_field_name, col_key))
+        return hl.MatrixTable(CastTableToMatrix(
+            self._tir, entries_field_name, cols_field_name, col_key))
 
     @staticmethod
     @typecheck(tables=sequenceof(table_type), data_field_name=str, global_field_name=str)
@@ -2632,9 +2634,7 @@ def _multi_way_zip_join(tables, data_field_name, global_field_name):
             raise TypeError('All input tables to multi_way_zip_join must have the same row type')
         if any(head.globals.dtype != t.globals.dtype for t in tables):
             raise TypeError('All input tables to multi_way_zip_join must have the same global type')
-        jt = Env.hail().table.Table.multiWayZipJoin([t._jt for t in tables],
-                                                    data_field_name,
-                                                    global_field_name)
-        return Table._from_java(jt)
+        return Table(TableMultiWayZipJoin(
+            [t._tir for t in tables], data_field_name, global_field_name))
 
 table_type.set(Table)
diff --git a/hail/python/hail/utils/java.py b/hail/python/hail/utils/java.py
index 2dc78e1492a..d82d269bb6a 100644
--- a/hail/python/hail/utils/java.py
+++ b/hail/python/hail/utils/java.py
@@ -61,6 +61,10 @@ def hc():
             assert Env._hc is not None
         return Env._hc
 
+    @staticmethod
+    def backend():
+        return Env.hc()._backend
+
     @staticmethod
     def sql_context():
         return Env.hc()._sql_context
diff --git a/hail/src/main/scala/is/hail/expr/ir/Parser.scala b/hail/src/main/scala/is/hail/expr/ir/Parser.scala
index 751a10ffc1c..a0a817a42ee 100644
--- a/hail/src/main/scala/is/hail/expr/ir/Parser.scala
+++ b/hail/src/main/scala/is/hail/expr/ir/Parser.scala
@@ -730,6 +730,13 @@ object IRParser {
         val child = table_ir(env)(it)
         val query = ir_value_expr(env.update(child.typ.refMap))(it)
         TableAggregate(child, query)
+      case "TableExport" =>
+        val child = table_ir(env)(it)
+        val path = string_literal(it)
+        val typesFile = opt(it, string_literal).orNull
+        val header = boolean_literal(it)
+        val exportType = int32_literal(it)
+        TableExport(child, path, typesFile, header, exportType)
       case "TableWrite" =>
         val path = string_literal(it)
         val overwrite = boolean_literal(it)
diff --git a/hail/src/main/scala/is/hail/table/Table.scala b/hail/src/main/scala/is/hail/table/Table.scala
index b74bfb70e0e..cdf3bdc9f26 100644
--- a/hail/src/main/scala/is/hail/table/Table.scala
+++ b/hail/src/main/scala/is/hail/table/Table.scala
@@ -439,17 +439,6 @@ class Table(val hc: HailContext, val tir: TableIR) {
       signature = keySignature ++ TStruct(name -> TArray(valueSignature)))
   }
 
-  def jToMatrixTable(rowKeys: java.util.ArrayList[String],
-    colKeys: java.util.ArrayList[String],
-    rowFields: java.util.ArrayList[String],
-    colFields: java.util.ArrayList[String],
-    nPartitions: java.lang.Integer): MatrixTable = {
-
-    toMatrixTable(rowKeys.asScala.toArray, colKeys.asScala.toArray,
-      rowFields.asScala.toArray, colFields.asScala.toArray,
-      Option(nPartitions).map(_.asInstanceOf[Int])
-    )
-  }
 
   def toMatrixTable(
     rowKeys: Array[String],