org.apache.hadoop.hive.serde2
Class ColumnProjectionUtils

java.lang.Object
  org.apache.hadoop.hive.serde2.ColumnProjectionUtils

public final class ColumnProjectionUtils
extends Object

ColumnProjectionUtils.

Field Summary

static String

READ_COLUMN_IDS_CONF_STR

Method Summary

static void	appendReadColumnIDs(Configuration conf, List<Integer> ids) Sets read columns' ids(start from zero) for RCFile's Reader.
static ArrayList<Integer>	getReadColumnIDs(Configuration conf) Returns an array of column ids(start from zero) which is set in the given parameter conf.
static void	setFullyReadColumns(Configuration conf) Clears the read column ids set in the conf, and will read all columns.
static void	setReadColumnIDs(Configuration conf, List<Integer> ids) Sets read columns' ids(start from zero) for RCFile's Reader.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

READ_COLUMN_IDS_CONF_STR

public static final String READ_COLUMN_IDS_CONF_STR

See Also:

Constant Field Values

Method Detail

setReadColumnIDs

public static void setReadColumnIDs(Configuration conf,
                                    List<Integer> ids)

Sets read columns' ids(start from zero) for RCFile's Reader. Once a column is included in the list, RCFile's reader will not skip its value.

appendReadColumnIDs

public static void appendReadColumnIDs(Configuration conf,
                                       List<Integer> ids)

Sets read columns' ids(start from zero) for RCFile's Reader. Once a column is included in the list, RCFile's reader will not skip its value.

getReadColumnIDs

public static ArrayList<Integer> getReadColumnIDs(Configuration conf)

Returns an array of column ids(start from zero) which is set in the given parameter conf.

setFullyReadColumns

public static void setFullyReadColumns(Configuration conf)

Clears the read column ids set in the conf, and will read all columns.