Refactor s3select to support parquet. (#7023)

Also handle pretty formatted JSON documents.

pkg/s3select/sql/record.go

@@ -0,0 +1,25 @@
+/*
+ * Minio Cloud Storage, (C) 2019 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package sql
+
+// Record - is a type containing columns and their values.
+type Record interface {
+	Get(name string) (*Value, error)
+	Set(name string, value *Value) error
+	MarshalCSV(fieldDelimiter rune) ([]byte, error)
+	MarshalJSON() ([]byte, error)
+}