[HBASE-3562] ValueFilter is being evaluated before performing the column match

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Abandoned
• Affects Version/s: 0.90.0, 0.94.7
• Component/s: Filters
• Assignee: Unassigned
• Reporter: Evert Arckens
• Created: 24/Feb/11 16:02
• Updated: 12/Jun/22 00:50
• Resolved: 12/Jun/22 00:50

Description

When performing a Get operation where a both a column is specified and a ValueFilter, the ValueFilter is evaluated before making the column match as is indicated in the javadoc of Get.setFilter() : "

{@link Filter#filterKeyValue(KeyValue)}

is called AFTER all tests for ttl, column match, deletes and max versions have been run. "

The is shown in the little test below, which uses a TestComparator extending a WritableByteArrayComparable.

public void testFilter() throws Exception {
byte[] cf = Bytes.toBytes("cf");
byte[] row = Bytes.toBytes("row");
byte[] col1 = Bytes.toBytes("col1");
byte[] col2 = Bytes.toBytes("col2");
Put put = new Put(row);
put.add(cf, col1, new byte[]

{(byte)1}

);
put.add(cf, col2, new byte[]

{(byte)2}

);
table.put(put);

Get get = new Get(row);
get.addColumn(cf, col2); // We only want to retrieve col2

TestComparator testComparator = new TestComparator();
Filter filter = new ValueFilter(CompareOp.EQUAL, testComparator);
get.setFilter(filter);
Result result = table.get(get);
}

public class TestComparator extends WritableByteArrayComparable {
/**

• Nullary constructor, for Writable
  */
  public TestComparator() { super(); }

@Override
public int compareTo(byte[] theirValue) {
if (theirValue[0] == (byte)1)

{ // If the column match was done before evaluating the filter, we should never get here. throw new RuntimeException("I only expect (byte)2 in col2, not (byte)1 from col1"); }

if (theirValue[0] == (byte)2)

{ return 0; }

else return 1;
}
}

When only one column should be retrieved, this can be worked around by using a SingleColumnValueFilter instead of the ValueFilter.

Issue Links

• relates to: HBASE-8930 Filter evaluates KVs outside requested columns
• relates to: HBASE-16225 Refactor ScanQueryMatcher