[GitHub] carbondata pull request #2127: [CARBONDATA-2301][SDK] CarbonStore interface ...

[ravipesala <gi...@git.apache.org>]

Github user ravipesala commented on a diff in the pull request:

    https://github.com/apache/carbondata/pull/2127#discussion_r179905076
  
    --- Diff: store/sdk/src/main/java/org/apache/carbondata/store/CarbonStore.java ---
    @@ -0,0 +1,67 @@
    +/*
    + * Licensed to the Apache Software Foundation (ASF) under one or more
    + * contributor license agreements.  See the NOTICE file distributed with
    + * this work for additional information regarding copyright ownership.
    + * The ASF licenses this file to You 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 org.apache.carbondata.store;
    +
    +import java.io.Closeable;
    +import java.io.IOException;
    +
    +import org.apache.carbondata.common.annotations.InterfaceAudience;
    +import org.apache.carbondata.common.annotations.InterfaceStability;
    +import org.apache.carbondata.core.datastore.row.CarbonRow;
    +import org.apache.carbondata.core.scan.expression.Expression;
    +
    +/**
    + * User can use {@link CarbonStore} to query data
    + */
    +@InterfaceAudience.User
    +@InterfaceStability.Unstable
    +public interface CarbonStore extends Closeable {
    +
    +  /**
    +   * Scan query on the data in the table path
    +   * @param path table path
    +   * @param projectColumns column names to read
    +   * @return rows
    +   * @throws IOException if unable to read files in table path
    +   */
    +  CarbonRow[] scan(
    --- End diff --
    
    I think it is better to return iterator rather than array, because in case of returning large rows it is not memory efficient to return all rows to driver. Internal implementation can have batch read from each executor and gives to drver.


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