Indexing on Multiple Columns

[Michelan Arendse <mi...@addynamo.com>]

Hi.

I am having trouble indexing multiple columns in hbase.
This is my code:
IndexKeyGenerator keyGen = new SimpleIndexKeyGenerator();

                  Map <byte[], byte[]> indexColumnsMap = new HashMap<byte[], byte[]>();

                  for ( int x =0; x < columns.length; x++)
                        indexColumnsMap.put(Bytes.toBytes(x), Bytes.toBytes(columns[x]));

                  keyGen.createIndexKey(Bytes.toBytes(tableName+ "IndexKey") , indexColumnsMap); // Problem lies here.
                  hbAdmin.addIndex(Bytes.toBytes(tableName), new IndexSpecification(tableName + "Index", Bytes.toByteArrays(columns), null, keyGen ));

I am able to index the tables in hbase, but when I want to index the table on multiple columns I get the following error:
Exception in thread "main" java.lang.NullPointerException
      at org.apache.hadoop.hbase.util.Bytes.add(Bytes.java:1131)
      at org.apache.hadoop.hbase.util.Bytes.add(Bytes.java:1121)
      at org.apache.hadoop.hbase.client.tableindexed.SimpleIndexKeyGenerator.createIndexKey(SimpleIndexKeyGenerator.java:46)

I read that SimpleIndexKeyGenerator is  used for single columns. If this is so please advise me on using another way of indexing the tables on multiple columns.

Thank you,

Michelan Arendse
Junior Developer | AD:DYNAMO // happy business ;-)
Office 0861 Dynamo (0861 396266)  | Fax +27 (0) 21 465 2587

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