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

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

setFullyReadColumns

public static void setFullyReadColumns(org.apache.hadoop.conf.Configuration conf)

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