diff --git a/parquet/metadata/statistics_test.go b/parquet/metadata/statistics_test.go
index d312437a..a0d107fa 100644
--- a/parquet/metadata/statistics_test.go
+++ b/parquet/metadata/statistics_test.go
@@ -603,3 +603,40 @@ func TestBooleanStatisticsUpdateFromBitmapSpaced(t *testing.T) {
 		assert.Equal(t, int64(8), stats.NullCount())
 	})
 }
+
+func TestNewStatisticsDistinctCountUnset(t *testing.T) {
+	// Issue #806: factories must not pre-set hasDistinctCount, otherwise
+	// Encode() emits distinct_count=0 for every column instead of leaving the
+	// optional Thrift field absent. IncDistinct() is responsible for marking
+	// it set when an actual distinct count is computed.
+	mk := func(n *schema.PrimitiveNode) metadata.TypedStatistics {
+		col := schema.NewColumn(n, 0, 0)
+		return metadata.NewStatistics(col, memory.DefaultAllocator)
+	}
+	cases := []struct {
+		name string
+		s    metadata.TypedStatistics
+	}{
+		{"Int32", mk(schema.NewInt32Node("i32", parquet.Repetitions.Required, -1))},
+		{"Int64", mk(schema.NewInt64Node("i64", parquet.Repetitions.Required, -1))},
+		{"Float32", mk(schema.NewFloat32Node("f32", parquet.Repetitions.Required, -1))},
+		{"Float64", mk(schema.NewFloat64Node("f64", parquet.Repetitions.Required, -1))},
+		{"Boolean", mk(schema.NewBooleanNode("b", parquet.Repetitions.Required, -1))},
+		{"ByteArray", mk(schema.NewByteArrayNode("ba", parquet.Repetitions.Required, -1))},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			assert.False(t, c.s.HasDistinctCount(), "fresh stats must not advertise a distinct count")
+			enc, err := c.s.Encode()
+			require.NoError(t, err)
+			assert.False(t, enc.HasDistinctCount, "encoded stats must leave distinct_count unset until IncDistinct is called")
+
+			c.s.IncDistinct(3)
+			assert.True(t, c.s.HasDistinctCount())
+			enc, err = c.s.Encode()
+			require.NoError(t, err)
+			assert.True(t, enc.HasDistinctCount)
+			assert.Equal(t, int64(3), enc.DistinctCount)
+		})
+	}
+}
diff --git a/parquet/metadata/statistics_types.gen.go b/parquet/metadata/statistics_types.gen.go
index a00010f9..a9a19ea1 100644
--- a/parquet/metadata/statistics_types.gen.go
+++ b/parquet/metadata/statistics_types.gen.go
@@ -57,12 +57,11 @@ func NewInt32Statistics(descr *schema.Column, mem memory.Allocator) *Int32Statis
 
 	return &Int32Statistics{
 		statistics: statistics{
-			descr:            descr,
-			hasNullCount:     true,
-			hasDistinctCount: true,
-			order:            descr.SortOrder(),
-			encoder:          encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
-			mem:              mem,
+			descr:        descr,
+			hasNullCount: true,
+			order:        descr.SortOrder(),
+			encoder:      encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
+			mem:          mem,
 		},
 	}
 }
@@ -358,12 +357,11 @@ func NewInt64Statistics(descr *schema.Column, mem memory.Allocator) *Int64Statis
 
 	return &Int64Statistics{
 		statistics: statistics{
-			descr:            descr,
-			hasNullCount:     true,
-			hasDistinctCount: true,
-			order:            descr.SortOrder(),
-			encoder:          encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
-			mem:              mem,
+			descr:        descr,
+			hasNullCount: true,
+			order:        descr.SortOrder(),
+			encoder:      encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
+			mem:          mem,
 		},
 	}
 }
@@ -659,12 +657,11 @@ func NewInt96Statistics(descr *schema.Column, mem memory.Allocator) *Int96Statis
 
 	return &Int96Statistics{
 		statistics: statistics{
-			descr:            descr,
-			hasNullCount:     true,
-			hasDistinctCount: true,
-			order:            descr.SortOrder(),
-			encoder:          encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
-			mem:              mem,
+			descr:        descr,
+			hasNullCount: true,
+			order:        descr.SortOrder(),
+			encoder:      encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
+			mem:          mem,
 		},
 	}
 }
@@ -938,12 +935,11 @@ func NewFloat32Statistics(descr *schema.Column, mem memory.Allocator) *Float32St
 
 	return &Float32Statistics{
 		statistics: statistics{
-			descr:            descr,
-			hasNullCount:     true,
-			hasDistinctCount: true,
-			order:            descr.SortOrder(),
-			encoder:          encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
-			mem:              mem,
+			descr:        descr,
+			hasNullCount: true,
+			order:        descr.SortOrder(),
+			encoder:      encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
+			mem:          mem,
 		},
 	}
 }
@@ -1231,12 +1227,11 @@ func NewFloat64Statistics(descr *schema.Column, mem memory.Allocator) *Float64St
 
 	return &Float64Statistics{
 		statistics: statistics{
-			descr:            descr,
-			hasNullCount:     true,
-			hasDistinctCount: true,
-			order:            descr.SortOrder(),
-			encoder:          encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
-			mem:              mem,
+			descr:        descr,
+			hasNullCount: true,
+			order:        descr.SortOrder(),
+			encoder:      encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
+			mem:          mem,
 		},
 	}
 }
@@ -1524,12 +1519,11 @@ func NewBooleanStatistics(descr *schema.Column, mem memory.Allocator) *BooleanSt
 
 	return &BooleanStatistics{
 		statistics: statistics{
-			descr:            descr,
-			hasNullCount:     true,
-			hasDistinctCount: true,
-			order:            descr.SortOrder(),
-			encoder:          encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
-			mem:              mem,
+			descr:        descr,
+			hasNullCount: true,
+			order:        descr.SortOrder(),
+			encoder:      encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
+			mem:          mem,
 		},
 	}
 }
@@ -1879,12 +1873,11 @@ func NewByteArrayStatistics(descr *schema.Column, mem memory.Allocator) *ByteArr
 
 	return &ByteArrayStatistics{
 		statistics: statistics{
-			descr:            descr,
-			hasNullCount:     true,
-			hasDistinctCount: true,
-			order:            descr.SortOrder(),
-			encoder:          encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
-			mem:              mem,
+			descr:        descr,
+			hasNullCount: true,
+			order:        descr.SortOrder(),
+			encoder:      encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
+			mem:          mem,
 		},
 
 		min: make([]byte, 0),
@@ -2187,12 +2180,11 @@ func NewFixedLenByteArrayStatistics(descr *schema.Column, mem memory.Allocator)
 
 	return &FixedLenByteArrayStatistics{
 		statistics: statistics{
-			descr:            descr,
-			hasNullCount:     true,
-			hasDistinctCount: true,
-			order:            descr.SortOrder(),
-			encoder:          encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
-			mem:              mem,
+			descr:        descr,
+			hasNullCount: true,
+			order:        descr.SortOrder(),
+			encoder:      encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
+			mem:          mem,
 		},
 	}
 }
@@ -2502,12 +2494,11 @@ func NewFloat16Statistics(descr *schema.Column, mem memory.Allocator) *Float16St
 
 	return &Float16Statistics{
 		statistics: statistics{
-			descr:            descr,
-			hasNullCount:     true,
-			hasDistinctCount: true,
-			order:            descr.SortOrder(),
-			encoder:          encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
-			mem:              mem,
+			descr:        descr,
+			hasNullCount: true,
+			order:        descr.SortOrder(),
+			encoder:      encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
+			mem:          mem,
 		},
 	}
 }
diff --git a/parquet/metadata/statistics_types.gen.go.tmpl b/parquet/metadata/statistics_types.gen.go.tmpl
index 83493998..76657943 100644
--- a/parquet/metadata/statistics_types.gen.go.tmpl
+++ b/parquet/metadata/statistics_types.gen.go.tmpl
@@ -62,7 +62,6 @@ func New{{.Name}}Statistics(descr *schema.Column, mem memory.Allocator) *{{.Name
     statistics: statistics{
       descr: descr,
       hasNullCount: true,
-      hasDistinctCount: true,
       order: descr.SortOrder(),
       encoder: encoding.NewEncoder(descr.PhysicalType(), parquet.Encodings.Plain, false, descr, mem),
       mem: mem,
diff --git a/parquet/pqarrow/file_writer_test.go b/parquet/pqarrow/file_writer_test.go
index 7b98b212..7ba4b85b 100644
--- a/parquet/pqarrow/file_writer_test.go
+++ b/parquet/pqarrow/file_writer_test.go
@@ -171,8 +171,8 @@ func TestFileWriterTotalBytes(t *testing.T) {
 	require.NoError(t, writer.Close())
 
 	// Verify total bytes & compressed bytes are correct
-	assert.Equal(t, int64(340), writer.TotalCompressedBytes())
-	assert.Equal(t, int64(799), writer.TotalBytesWritten())
+	assert.Equal(t, int64(332), writer.TotalCompressedBytes())
+	assert.Equal(t, int64(783), writer.TotalBytesWritten())
 }
 
 func TestFileWriterTotalBytesBuffered(t *testing.T) {
@@ -205,8 +205,8 @@ func TestFileWriterTotalBytesBuffered(t *testing.T) {
 	require.NoError(t, writer.Close())
 
 	// Verify total bytes & compressed bytes are correct
-	assert.Equal(t, int64(494), writer.TotalCompressedBytes())
-	assert.Equal(t, int64(1139), writer.TotalBytesWritten())
+	assert.Equal(t, int64(482), writer.TotalCompressedBytes())
+	assert.Equal(t, int64(1115), writer.TotalBytesWritten())
 }
 
 func TestWriteOnClosedFileWriter(t *testing.T) {