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HBase >> mail # dev >> Constructing rowkeys and HBASE-7221


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Constructing rowkeys and HBASE-7221

Greetings folks-

I would like to restart the conversation on https://issues.apache.org/jira/browse/HBASE-7221 because there continue to be conversations on the dist-list about creating composite rowkeys, and while HBase makes just about anything possible, it doesn’t make much easy in this respect.

What I’m lobbying for is a utility class (see the v3 patch in HBASE-7221) that can both create and read rowkeys (so this isn’t just a one-way builder pattern).

This is currently stuck because it was noted that Bytes has an issue with sort-order of numbers specifically if you have both negative and positive values, which is really a different issue, but because this patch uses Bytes it’s related.

What are people’s thoughts on this topic in general, and the v3 version of the patch specifically?  (and the last set of comments).  Thanks!

One of the unit tests shows the example of usage.  The last set of comments suggested that RowKey be renamed FixedLengthRowKey, which I think is a good idea.  A follow-on patch could include VariableLengthRowKey for folks that use strings in the rowkeys.
  public void testCreate() throws Exception {

    int elements[] = {RowKeySchema.SIZEOF_MD5_HASH, RowKeySchema.SIZEOF_INT, RowKeySchema.SIZEOF_LONG};
    RowKeySchema schema = new RowKeySchema(elements);

    RowKey rowkey = schema.createRowKey();
    rowkey.setHash(0, hashVal);
    rowkey.setInt(1, intVal);
    rowkey.setLong(2, longVal);

    byte bytes[] = rowkey.getBytes();
    Assert.assertEquals("key length", schema.getRowKeyLength(), bytes.length);

    Assert.assertEquals("e1", rowkey.getInt(1), intVal);
    Assert.assertEquals("e2", rowkey.getLong(2), longVal);
  }

Doug Meil
Chief Software Architect, Explorys
[EMAIL PROTECTED]