Modifier and Type | Field and Description |
---|---|
protected byte[][] |
columns |
static java.lang.String |
GROUP_COLUMNS
JobConf parameter to specify the columns used to produce the key passed to
collect from the map phase
|
Constructor and Description |
---|
GroupingTableMap() |
Modifier and Type | Method and Description |
---|---|
void |
configure(JobConf job) |
protected ImmutableBytesWritable |
createGroupKey(byte[][] vals)
Create a key by concatenating multiple column values.
|
protected byte[][] |
extractKeyValues(Result r)
Extract columns values from the current record.
|
static void |
initJob(java.lang.String table,
java.lang.String columns,
java.lang.String groupColumns,
java.lang.Class<? extends TableMap> mapper,
JobConf job)
Use this before submitting a TableMap job.
|
void |
map(ImmutableBytesWritable key,
Result value,
<any> output,
Reporter reporter)
Extract the grouping columns from value to construct a new key.
|
public static final java.lang.String GROUP_COLUMNS
protected byte[][] columns
public static void initJob(java.lang.String table, java.lang.String columns, java.lang.String groupColumns, java.lang.Class<? extends TableMap> mapper, JobConf job)
table
- table to be processedcolumns
- space separated list of columns to fetchgroupColumns
- space separated list of columns used to form the key
used in collectmapper
- map classjob
- job configuration objectpublic void configure(JobConf job)
public void map(ImmutableBytesWritable key, Result value, <any> output, Reporter reporter) throws java.io.IOException
key
- value
- output
- reporter
- java.io.IOException
protected byte[][] extractKeyValues(Result r)
r
- protected ImmutableBytesWritable createGroupKey(byte[][] vals)
vals
-