Java 类org.apache.cassandra.thrift.IndexOperator 实例源码

/**
 * Returns IndexOperator from string representation
 * @param operator - string representing IndexOperator (=, >=, >, <, <=)
 * @return IndexOperator - enum value of IndexOperator or null if not found
 */
public static IndexOperator getIndexOperator(String operator)
{
    if (operator.equals("="))
    {
        return IndexOperator.EQ;
    }
    else if (operator.equals(">="))
    {
        return IndexOperator.GTE;
    }
    else if (operator.equals(">"))
    {
        return IndexOperator.GT;
    }
    else if (operator.equals("<"))
    {
        return IndexOperator.LT;
    }
    else if (operator.equals("<="))
    {
        return IndexOperator.LTE;
    }

    return null;
}

/**
 * Returns IndexOperator from string representation
 * @param operator - string representing IndexOperator (=, >=, >, <, <=)
 * @return IndexOperator - enum value of IndexOperator or null if not found
 */
public static IndexOperator getIndexOperator(String operator)
{
    if (operator.equals("="))
    {
        return IndexOperator.EQ;
    }
    else if (operator.equals(">="))
    {
        return IndexOperator.GTE;
    }
    else if (operator.equals(">"))
    {
        return IndexOperator.GT;
    }
    else if (operator.equals("<"))
    {
        return IndexOperator.LT;
    }
    else if (operator.equals("<="))
    {
        return IndexOperator.LTE;
    }

    return null;
}

private static int getPriority(IndexOperator op)
{
    switch (op)
    {
        case EQ:
            return 4;

        case GTE:
        case GT:
            return 3;

        case LTE:
        case LT:
            return 2;

        case NOT_EQ:
            return 1;

        default:
            return 0;
    }
}

@Test
public void testSatisfiedByWithMultipleTerms()
{
    final ByteBuffer comment = UTF8Type.instance.decompose("comment");
    final ColumnFamilyStore store = Keyspace.open("sasecondaryindex").getColumnFamilyStore("saindexed1");
    final IPartitioner<?> partitioner = StorageService.getPartitioner();

    ColumnFamily cf = ArrayBackedSortedColumns.factory.create(store.metadata);
    cf.addColumn(new Column(comment, UTF8Type.instance.decompose("software engineer is working on a project"), System.currentTimeMillis()));

    Operation.Builder builder = new Operation.Builder(OperationType.AND, UTF8Type.instance, controller,
                                        new IndexExpression(comment, IndexOperator.EQ, UTF8Type.instance.decompose("eng is a work")));
    Operation op = builder.complete();

    Assert.assertTrue(op.satisfiedBy(new Row(partitioner.decorateKey(UTF8Type.instance.decompose("key1")), cf), null, false));

    builder = new Operation.Builder(OperationType.AND, UTF8Type.instance, controller,
                                        new IndexExpression(comment, IndexOperator.EQ, UTF8Type.instance.decompose("soft works fine")));
    op = builder.complete();

    Assert.assertTrue(op.satisfiedBy(new Row(partitioner.decorateKey(UTF8Type.instance.decompose("key1")), cf), null, false));
}

/**
 * Returns IndexOperator from string representation
 * @param operator - string representing IndexOperator (=, >=, >, <, <=)
 * @return IndexOperator - enum value of IndexOperator or null if not found
 */
public static IndexOperator getIndexOperator(String operator)
{
    if (operator.equals("="))
    {
        return IndexOperator.EQ;
    }
    else if (operator.equals(">="))
    {
        return IndexOperator.GTE;
    }
    else if (operator.equals(">"))
    {
        return IndexOperator.GT;
    }
    else if (operator.equals("<"))
    {
        return IndexOperator.LT;
    }
    else if (operator.equals("<="))
    {
        return IndexOperator.LTE;
    }

    return null;
}

public static boolean satisfies(int comparison, IndexOperator op)
{
    switch (op)
    {
        case EQ:
            return comparison == 0;
        case GTE:
            return comparison >= 0;
        case GT:
            return comparison > 0;
        case LTE:
            return comparison <= 0;
        case LT:
            return comparison < 0;
        default:
            throw new IllegalStateException();
    }
}

/**
 * Returns IndexOperator from string representation
 * @param operator - string representing IndexOperator (=, >=, >, <, <=)
 * @return IndexOperator - enum value of IndexOperator or null if not found
 */
public static IndexOperator getIndexOperator(String operator)
{
    if (operator.equals("="))
    {
        return IndexOperator.EQ;
    }
    else if (operator.equals(">="))
    {
        return IndexOperator.GTE;
    }
    else if (operator.equals(">"))
    {
        return IndexOperator.GT;
    }
    else if (operator.equals("<"))
    {
        return IndexOperator.LT;
    }
    else if (operator.equals("<="))
    {
        return IndexOperator.LTE;
    }

    return null;
}

/**
 * Returns IndexOperator from string representation
 * @param operator - string representing IndexOperator (=, >=, >, <, <=)
 * @return IndexOperator - enum value of IndexOperator or null if not found
 */
public static IndexOperator getIndexOperator(String operator)
{
    if (operator.equals("="))
    {
        return IndexOperator.EQ;
    }
    else if (operator.equals(">="))
    {
        return IndexOperator.GTE;
    }
    else if (operator.equals(">"))
    {
        return IndexOperator.GT;
    }
    else if (operator.equals("<"))
    {
        return IndexOperator.LT;
    }
    else if (operator.equals("<="))
    {
        return IndexOperator.LTE;
    }

    return null;
}

/**
 * Returns IndexOperator from string representation
 * @param operator - string representing IndexOperator (=, >=, >, <, <=)
 * @return IndexOperator - enum value of IndexOperator or null if not found
 */
public static IndexOperator getIndexOperator(String operator)
{
    if (operator.equals("="))
    {
        return IndexOperator.EQ;
    }
    else if (operator.equals(">="))
    {
        return IndexOperator.GTE;
    }
    else if (operator.equals(">"))
    {
        return IndexOperator.GT;
    }
    else if (operator.equals("<"))
    {
        return IndexOperator.LT;
    }
    else if (operator.equals("<="))
    {
        return IndexOperator.LTE;
    }

    return null;
}

public static boolean satisfies(int comparison, IndexOperator op)
{
    switch (op)
    {
        case EQ:
            return comparison == 0;
        case GTE:
            return comparison >= 0;
        case GT:
            return comparison > 0;
        case LTE:
            return comparison <= 0;
        case LT:
            return comparison < 0;
        default:
            throw new IllegalStateException();
    }
}

/**
 * Returns IndexOperator from string representation
 * @param operator - string representing IndexOperator (=, >=, >, <, <=)
 * @return IndexOperator - enum value of IndexOperator or null if not found
 */
public static IndexOperator getIndexOperator(String operator)
{
    if (operator.equals("="))
    {
        return IndexOperator.EQ;
    }
    else if (operator.equals(">="))
    {
        return IndexOperator.GTE;
    }
    else if (operator.equals(">"))
    {
        return IndexOperator.GT;
    }
    else if (operator.equals("<"))
    {
        return IndexOperator.LT;
    }
    else if (operator.equals("<="))
    {
        return IndexOperator.LTE;
    }

    return null;
}

/**
 * Returns IndexOperator from string representation
 * @param operator - string representing IndexOperator (=, >=, >, <, <=)
 * @return IndexOperator - enum value of IndexOperator or null if not found
 */
public static IndexOperator getIndexOperator(String operator)
{
    if (operator.equals("="))
    {
        return IndexOperator.EQ;
    }
    else if (operator.equals(">="))
    {
        return IndexOperator.GTE;
    }
    else if (operator.equals(">"))
    {
        return IndexOperator.GT;
    }
    else if (operator.equals("<"))
    {
        return IndexOperator.LT;
    }
    else if (operator.equals("<="))
    {
        return IndexOperator.LTE;
    }

    return null;
}

public static boolean satisfies(int comparison, IndexOperator op)
{
    switch (op)
    {
        case EQ:
            return comparison == 0;
        case GTE:
            return comparison >= 0;
        case GT:
            return comparison > 0;
        case LTE:
            return comparison <= 0;
        case LT:
            return comparison < 0;
        default:
            throw new IllegalStateException();
    }
}

/**
 * Returns IndexOperator from string representation
 * @param operator - string representing IndexOperator (=, >=, >, <, <=)
 * @return IndexOperator - enum value of IndexOperator or null if not found
 */
public static IndexOperator getIndexOperator(String operator)
{
    if (operator.equals("="))
    {
        return IndexOperator.EQ;
    }
    else if (operator.equals(">="))
    {
        return IndexOperator.GTE;
    }
    else if (operator.equals(">"))
    {
        return IndexOperator.GT;
    }
    else if (operator.equals("<"))
    {
        return IndexOperator.LT;
    }
    else if (operator.equals("<="))
    {
        return IndexOperator.LTE;
    }

    return null;
}

private IndexExpression highestSelectivityPredicate(IndexClause clause)
{
    IndexExpression best = null;
    int bestMeanCount = Integer.MAX_VALUE;
    for (IndexExpression expression : clause.expressions)
    {
        ColumnFamilyStore cfs = getIndexedColumnFamilyStore(expression.column_name);
        if (cfs == null || !expression.op.equals(IndexOperator.EQ))
            continue;
        int columns = cfs.getMeanColumns();
        if (columns < bestMeanCount)
        {
            best = expression;
            bestMeanCount = columns;
        }
    }
    return best;
}

private static boolean satisfies(int comparison, IndexOperator op)
{
    switch (op)
    {
        case EQ:
            return comparison == 0;
        case GTE:
            return comparison >= 0;
        case GT:
            return comparison > 0;
        case LTE:
            return comparison <= 0;
        case LT:
            return comparison < 0;
        default:
            throw new IllegalStateException();
    }
}

/**
 * Returns IndexOperator from string representation
 * @param operator - string representing IndexOperator (=, >=, >, <, <=)
 * @return IndexOperator - enum value of IndexOperator or null if not found
 */
public static IndexOperator getIndexOperator(String operator)
{
    if (operator.equals("="))
    {
        return IndexOperator.EQ;
    }
    else if (operator.equals(">="))
    {
        return IndexOperator.GTE;
    }
    else if (operator.equals(">"))
    {
        return IndexOperator.GT;
    }
    else if (operator.equals("<"))
    {
        return IndexOperator.LT;
    }
    else if (operator.equals("<="))
    {
        return IndexOperator.LTE;
    }

    return null;
}

private static Expression expressionFor(long lower, boolean lowerInclusive, long upper, boolean upperInclusive)
{
    Expression expression = new Expression(ByteBufferUtil.EMPTY_BYTE_BUFFER, LongType.instance);
    expression.add(lowerInclusive ? IndexOperator.GTE : IndexOperator.GT, LongType.instance.decompose(lower));
    expression.add(upperInclusive ? IndexOperator.LTE : IndexOperator.LT, LongType.instance.decompose(upper));
    return expression;
}

private static Expression expressionForNot(AbstractType<?> validator, ByteBuffer lower, ByteBuffer upper, Iterable<ByteBuffer> terms)
{
    Expression expression = new Expression(ByteBufferUtil.EMPTY_BYTE_BUFFER, validator);
    expression.setOp(Expression.Op.RANGE);
    expression.setLower(new Expression.Bound(lower, true));
    expression.setUpper(new Expression.Bound(upper, true));
    for (ByteBuffer term : terms)
        expression.add(IndexOperator.NOT_EQ, term);
    return expression;

}

private static Expression rangeWithExclusions(long lower, boolean lowerInclusive, long upper, boolean upperInclusive, Set<Long> exclusions)
{
    Expression expression = expressionFor(lower, lowerInclusive, upper, upperInclusive);
    for (long e : exclusions)
        expression.add(IndexOperator.NOT_EQ, LongType.instance.decompose(e));

    return expression;
}

public IndexOperator getIndexOperator(Bound b)
{
    switch (b)
    {
        case START:
            return boundInclusive[b.idx] ? IndexOperator.GTE : IndexOperator.GT;
        case END:
            return boundInclusive[b.idx] ? IndexOperator.LTE : IndexOperator.LT;
    }
    throw new AssertionError();
}

public IndexOperator getIndexOperator(Bound b)
{
    switch (b)
    {
        case START:
            return boundInclusive[b.idx] ? IndexOperator.GTE : IndexOperator.GT;
        case END:
            return boundInclusive[b.idx] ? IndexOperator.LTE : IndexOperator.LT;
    }
    throw new AssertionError();
}

public IndexOperator getIndexOperator(Bound b)
{
    switch (b)
    {
        case START:
            return boundInclusive[b.idx] ? IndexOperator.GTE : IndexOperator.GT;
        case END:
            return boundInclusive[b.idx] ? IndexOperator.LTE : IndexOperator.LT;
    }
    throw new AssertionError();
}

@VisibleForTesting
protected static ListMultimap<ByteBuffer, Expression> analyzeGroup(QueryController controller,
                                                                   final AbstractType<?> comparator,
                                                                   OperationType op,
                                                                   List<IndexExpression> expressions)
{
    ListMultimap<ByteBuffer, Expression> analyzed = ArrayListMultimap.create();

    // sort all of the expressions in the operation by name and priority of the logical operator
    // this gives us an efficient way to handle inequality and combining into ranges without extra processing
    // and converting expressions from one type to another.
    Collections.sort(expressions, new Comparator<IndexExpression>()
    {
        @Override
        public int compare(IndexExpression a, IndexExpression b)
        {
            int cmp = comparator.compare(ByteBuffer.wrap(a.getColumn_name()), ByteBuffer.wrap(b.getColumn_name()));
            return cmp == 0 ? -Integer.compare(getPriority(a.getOp()), getPriority(b.getOp())) : cmp;
        }
    });

    for (final IndexExpression e : expressions)
    {
        if (e.isSetLogicalOp())
            continue;

        ByteBuffer name = ByteBuffer.wrap(e.getColumn_name());
        ColumnIndex columnIndex = controller.getIndex(name);

        List<Expression> perColumn = analyzed.get(name);

        if (columnIndex == null)
        {
            ColumnDefinition nonIndexedColumn = controller.getColumn(name);
            columnIndex = new ColumnIndex(controller.getKeyValidator(),
                                          nonIndexedColumn,
                                          controller.getComparator(nonIndexedColumn));
        }

        AbstractAnalyzer analyzer = columnIndex.getAnalyzer();
        analyzer.reset(ByteBuffer.wrap(e.getValue()));

        // EQ/NOT_EQ can have multiple expressions e.g. text = "Hello World",
        // becomes text = "Hello" OR text = "World" because "space" is always interpreted as a split point (by analyzer),
        // NOT_EQ is made an independent expression only in case of pre-existing multiple EQ expressions, or
        // if there is no EQ operations and NOT_EQ is met or a single NOT_EQ expression present,
        // in such case we know exactly that there would be no more EQ/RANGE expressions for given column
        // since NOT_EQ has the lowest priority.
        if (e.getOp() == IndexOperator.EQ
                || (e.getOp() == IndexOperator.NOT_EQ
                   && (perColumn.size() == 0 || perColumn.size() > 1
                       || (perColumn.size() == 1 && perColumn.get(0).getOp() == Op.NOT_EQ))))
        {
            while (analyzer.hasNext())
            {
                final ByteBuffer token = analyzer.next();
                perColumn.add(new Expression(controller, columnIndex)
                {{
                        add(e.op, token);
                }});
            }
        }
        else
        // "range" or not-equals operator, combines both bounds together into the single expression,
        // iff operation of the group is AND, otherwise we are forced to create separate expressions,
        // not-equals is combined with the range iff operator is AND.
        {
            Expression range;
            if (perColumn.size() == 0 || op != OperationType.AND)
                perColumn.add((range = new Expression(controller, columnIndex)));
            else
                range = Iterables.getLast(perColumn);

            while (analyzer.hasNext())
                range.add(e.op, analyzer.next());
        }
    }

    return analyzed;
}

public Expression add(IndexOperator op, ByteBuffer value)
{
    boolean lowerInclusive = false, upperInclusive = false;
    switch (op)
    {
        case EQ:
            lower = new Bound(value, true);
            upper = lower;
            operation = Op.EQ;
            break;

        case NOT_EQ:
            // index expressions are priority sorted
            // and NOT_EQ is the lowest priority, which means that operation type
            // is always going to be set before reaching it in case of RANGE or EQ.
            if (operation == null)
            {
                operation = Op.NOT_EQ;
                lower = new Bound(value, true);
                upper = lower;
            }
            else
                exclusions.add(value);
            break;

        case LTE:
            upperInclusive = true;
        case LT:
            operation = Op.RANGE;
            upper = new Bound(value, upperInclusive);
            break;

        case GTE:
            lowerInclusive = true;
        case GT:
            operation = Op.RANGE;
            lower = new Bound(value, lowerInclusive);
            break;
    }

    return this;
}

@Test
public void testRangeQueryWithExclusions() throws Exception
{
    final long lower = 0;
    final long upper = 100000;

    OnDiskIndexBuilder builder = new OnDiskIndexBuilder(UTF8Type.instance, LongType.instance, OnDiskIndexBuilder.Mode.SPARSE);
    for (long i = lower; i <= upper; i++)
        builder.add(LongType.instance.decompose(i), keyAt(i), i);

    File index = File.createTempFile("on-disk-sa-except-long-ranges", "db");
    index.deleteOnExit();

    builder.finish(index);

    OnDiskIndex onDisk = new OnDiskIndex(index, LongType.instance, new KeyConverter());

    ThreadLocalRandom random = ThreadLocalRandom.current();

    // single exclusion

    // let's do small range first to figure out if searchPoint works properly
    validateExclusions(onDisk, lower, 50, Sets.newHashSet(42L));
    // now let's do whole data set to test SPARSE searching
    validateExclusions(onDisk, lower, upper, Sets.newHashSet(31337L));

    // pair of exclusions which would generate a split

    validateExclusions(onDisk, lower, random.nextInt(400, 800), Sets.newHashSet(42L, 154L));
    validateExclusions(onDisk, lower, upper, Sets.newHashSet(31337L, 54631L));

    // 3 exclusions which would generate a split and change bounds

    validateExclusions(onDisk, lower, random.nextInt(400, 800), Sets.newHashSet(42L, 154L));
    validateExclusions(onDisk, lower, upper, Sets.newHashSet(31337L, 54631L));

    validateExclusions(onDisk, lower, random.nextLong(400, upper), Sets.newHashSet(42L, 55L));
    validateExclusions(onDisk, lower, random.nextLong(400, upper), Sets.newHashSet(42L, 55L, 93L));
    validateExclusions(onDisk, lower, random.nextLong(400, upper), Sets.newHashSet(42L, 55L, 93L, 205L));

    Set<Long> exclusions = Sets.newHashSet(3L, 12L, 13L, 14L, 27L, 54L, 81L, 125L, 384L, 771L, 1054L, 2048L, 78834L);

    // test that exclusions are properly bound by lower/upper of the expression
    Assert.assertEquals(392, validateExclusions(onDisk, lower, 400, exclusions, false));
    Assert.assertEquals(101, validateExclusions(onDisk, lower, 100, Sets.newHashSet(-10L, -5L, -1L), false));

    validateExclusions(onDisk, lower, upper, exclusions);

    Assert.assertEquals(100000, convert(onDisk.search(new Expression(ByteBufferUtil.EMPTY_BYTE_BUFFER, LongType.instance)
                                                .add(IndexOperator.NOT_EQ, LongType.instance.decompose(100L)))).size());

    Assert.assertEquals(49, convert(onDisk.search(new Expression(ByteBufferUtil.EMPTY_BYTE_BUFFER, LongType.instance)
                                                .add(IndexOperator.LT, LongType.instance.decompose(50L))
                                                .add(IndexOperator.NOT_EQ, LongType.instance.decompose(10L)))).size());

    Assert.assertEquals(99998, convert(onDisk.search(new Expression(ByteBufferUtil.EMPTY_BYTE_BUFFER, LongType.instance)
                                                .add(IndexOperator.GT, LongType.instance.decompose(1L))
                                                .add(IndexOperator.NOT_EQ, LongType.instance.decompose(20L)))).size());

    onDisk.close();
}

private static Expression expressionFor(AbstractType<?> validator, ByteBuffer term)
{
    Expression expression = new Expression(ByteBufferUtil.EMPTY_BYTE_BUFFER, validator);
    expression.add(IndexOperator.EQ, term);
    return expression;
}

@Test
public void testAnalyzeNotIndexedButDefinedColumn() throws Exception
{
    final ByteBuffer firstName = UTF8Type.instance.decompose("first_name");
    final ByteBuffer height = UTF8Type.instance.decompose("height");
    final ByteBuffer notDefined = UTF8Type.instance.decompose("not-defined");

    // first_name = 'a' AND height != 10
    Map<Expression.Op, Expression> expressions;
    expressions = convert(Operation.analyzeGroup(controller, UTF8Type.instance, OperationType.AND,
            Arrays.asList(new IndexExpression(firstName, IndexOperator.EQ, UTF8Type.instance.decompose("a")),
                          new IndexExpression(height, IndexOperator.NOT_EQ, Int32Type.instance.decompose(5)))));

    Assert.assertEquals(2, expressions.size());

    Assert.assertEquals(new Expression(height, Int32Type.instance)
    {{
            operation = Op.NOT_EQ;
            lower = new Bound(Int32Type.instance.decompose(5), true);
            upper = lower;
    }}, expressions.get(Expression.Op.NOT_EQ));

    expressions = convert(Operation.analyzeGroup(controller, UTF8Type.instance, OperationType.AND,
            Arrays.asList(new IndexExpression(firstName, IndexOperator.EQ, UTF8Type.instance.decompose("a")),
                          new IndexExpression(height, IndexOperator.GT, Int32Type.instance.decompose(0)),
                          new IndexExpression(height, IndexOperator.NOT_EQ, Int32Type.instance.decompose(5)))));

    Assert.assertEquals(2, expressions.size());

    Assert.assertEquals(new Expression(height, Int32Type.instance)
    {{
        operation = Op.RANGE;
        lower = new Bound(Int32Type.instance.decompose(0), false);
        exclusions.add(Int32Type.instance.decompose(5));
    }}, expressions.get(Expression.Op.RANGE));

    expressions = convert(Operation.analyzeGroup(controller, UTF8Type.instance, OperationType.AND,
            Arrays.asList(new IndexExpression(firstName, IndexOperator.EQ, UTF8Type.instance.decompose("a")),
                          new IndexExpression(height, IndexOperator.NOT_EQ, Int32Type.instance.decompose(5)),
                          new IndexExpression(height, IndexOperator.GTE, Int32Type.instance.decompose(0)),
                          new IndexExpression(height, IndexOperator.LT, Int32Type.instance.decompose(10)))));

    Assert.assertEquals(2, expressions.size());

    Assert.assertEquals(new Expression(height, Int32Type.instance)
    {{
            operation = Op.RANGE;
            lower = new Bound(Int32Type.instance.decompose(0), true);
            upper = new Bound(Int32Type.instance.decompose(10), false);
            exclusions.add(Int32Type.instance.decompose(5));
    }}, expressions.get(Expression.Op.RANGE));


    expressions = convert(Operation.analyzeGroup(controller, UTF8Type.instance, OperationType.AND,
                    new ArrayList<IndexExpression>() {{ add(new IndexExpression(notDefined, IndexOperator.EQ, UTF8Type.instance.decompose("a"))); }}));

    Assert.assertEquals(1, expressions.size());
}

private static List<org.apache.cassandra.db.Row> multiRangeSlice(CFMetaData metadata, SelectStatement select, List<ByteBuffer> variables)
throws ReadTimeoutException, UnavailableException, InvalidRequestException
{
    IPartitioner<?> p = StorageService.getPartitioner();

    AbstractType<?> keyType = Schema.instance.getCFMetaData(metadata.ksName, select.getColumnFamily()).getKeyValidator();

    ByteBuffer startKeyBytes = (select.getKeyStart() != null)
                               ? select.getKeyStart().getByteBuffer(keyType,variables)
                               : null;

    ByteBuffer finishKeyBytes = (select.getKeyFinish() != null)
                                ? select.getKeyFinish().getByteBuffer(keyType,variables)
                                : null;

    RowPosition startKey = RowPosition.forKey(startKeyBytes, p), finishKey = RowPosition.forKey(finishKeyBytes, p);
    if (startKey.compareTo(finishKey) > 0 && !finishKey.isMinimum(p))
    {
        if (p instanceof RandomPartitioner)
            throw new InvalidRequestException("Start key sorts after end key. This is not allowed; you probably should not specify end key at all, under RandomPartitioner");
        else
            throw new InvalidRequestException("Start key must sort before (or equal to) finish key in your partitioner!");
    }
    AbstractBounds<RowPosition> bounds = new Bounds<RowPosition>(startKey, finishKey);

    IDiskAtomFilter columnFilter = filterFromSelect(select, metadata, variables);
    validateFilter(metadata, columnFilter);

    List<Relation> columnRelations = select.getColumnRelations();
    List<IndexExpression> expressions = new ArrayList<IndexExpression>(columnRelations.size());
    for (Relation columnRelation : columnRelations)
    {
        // Left and right side of relational expression encoded according to comparator/validator.
        ByteBuffer entity = columnRelation.getEntity().getByteBuffer(metadata.comparator, variables);
        ByteBuffer value = columnRelation.getValue().getByteBuffer(select.getValueValidator(metadata.ksName, entity), variables);

        expressions.add(new IndexExpression(entity,
                                            IndexOperator.valueOf(columnRelation.operator().toString()),
                                            value));
    }

    int limit = select.isKeyRange() && select.getKeyStart() != null
              ? select.getNumRecords() + 1
              : select.getNumRecords();

    List<org.apache.cassandra.db.Row> rows = StorageProxy.getRangeSlice(new RangeSliceCommand(metadata.ksName,
                                                                                              select.getColumnFamily(),
                                                                                              null,
                                                                                              columnFilter,
                                                                                              bounds,
                                                                                              expressions,
                                                                                              limit),
                                                                        select.getConsistencyLevel());

    // if start key was set and relation was "greater than"
    if (select.getKeyStart() != null && !select.includeStartKey() && !rows.isEmpty())
    {
        if (rows.get(0).key.key.equals(startKeyBytes))
            rows.remove(0);
    }

    // if finish key was set and relation was "less than"
    if (select.getKeyFinish() != null && !select.includeFinishKey() && !rows.isEmpty())
    {
        int lastIndex = rows.size() - 1;
        if (rows.get(lastIndex).key.key.equals(finishKeyBytes))
            rows.remove(lastIndex);
    }

    return rows.subList(0, select.getNumRecords() < rows.size() ? select.getNumRecords() : rows.size());
}

private static List<org.apache.cassandra.db.Row> multiRangeSlice(CFMetaData metadata, SelectStatement select, List<ByteBuffer> variables)
throws ReadTimeoutException, UnavailableException, InvalidRequestException
{
    IPartitioner<?> p = StorageService.getPartitioner();

    AbstractType<?> keyType = Schema.instance.getCFMetaData(metadata.ksName, select.getColumnFamily()).getKeyValidator();

    ByteBuffer startKeyBytes = (select.getKeyStart() != null)
                               ? select.getKeyStart().getByteBuffer(keyType,variables)
                               : null;

    ByteBuffer finishKeyBytes = (select.getKeyFinish() != null)
                                ? select.getKeyFinish().getByteBuffer(keyType,variables)
                                : null;

    RowPosition startKey = RowPosition.forKey(startKeyBytes, p), finishKey = RowPosition.forKey(finishKeyBytes, p);
    if (startKey.compareTo(finishKey) > 0 && !finishKey.isMinimum(p))
    {
        if (p instanceof RandomPartitioner)
            throw new InvalidRequestException("Start key sorts after end key. This is not allowed; you probably should not specify end key at all, under RandomPartitioner");
        else
            throw new InvalidRequestException("Start key must sort before (or equal to) finish key in your partitioner!");
    }
    AbstractBounds<RowPosition> bounds = new Bounds<RowPosition>(startKey, finishKey);

    IDiskAtomFilter columnFilter = filterFromSelect(select, metadata, variables);
    validateFilter(metadata, columnFilter);

    List<Relation> columnRelations = select.getColumnRelations();
    List<IndexExpression> expressions = new ArrayList<IndexExpression>(columnRelations.size());
    for (Relation columnRelation : columnRelations)
    {
        // Left and right side of relational expression encoded according to comparator/validator.
        ByteBuffer entity = columnRelation.getEntity().getByteBuffer(metadata.comparator, variables);
        ByteBuffer value = columnRelation.getValue().getByteBuffer(select.getValueValidator(metadata.ksName, entity), variables);

        expressions.add(new IndexExpression(entity,
                                            IndexOperator.valueOf(columnRelation.operator().toString()),
                                            value));
    }

    int limit = select.isKeyRange() && select.getKeyStart() != null
              ? select.getNumRecords() + 1
              : select.getNumRecords();

    List<org.apache.cassandra.db.Row> rows = StorageProxy.getRangeSlice(new RangeSliceCommand(metadata.ksName,
                                                                                              select.getColumnFamily(),
                                                                                              null,
                                                                                              columnFilter,
                                                                                              bounds,
                                                                                              expressions,
                                                                                              limit),
                                                                        select.getConsistencyLevel());

    // if start key was set and relation was "greater than"
    if (select.getKeyStart() != null && !select.includeStartKey() && !rows.isEmpty())
    {
        if (rows.get(0).key.key.equals(startKeyBytes))
            rows.remove(0);
    }

    // if finish key was set and relation was "less than"
    if (select.getKeyFinish() != null && !select.includeFinishKey() && !rows.isEmpty())
    {
        int lastIndex = rows.size() - 1;
        if (rows.get(lastIndex).key.key.equals(finishKeyBytes))
            rows.remove(lastIndex);
    }

    return rows.subList(0, select.getNumRecords() < rows.size() ? select.getNumRecords() : rows.size());
}

private static List<org.apache.cassandra.db.Row> multiRangeSlice(CFMetaData metadata, SelectStatement select, List<ByteBuffer> variables)
throws ReadTimeoutException, UnavailableException, InvalidRequestException
{
    IPartitioner<?> p = StorageService.getPartitioner();

    AbstractType<?> keyType = Schema.instance.getCFMetaData(metadata.ksName, select.getColumnFamily()).getKeyValidator();

    ByteBuffer startKeyBytes = (select.getKeyStart() != null)
                               ? select.getKeyStart().getByteBuffer(keyType,variables)
                               : null;

    ByteBuffer finishKeyBytes = (select.getKeyFinish() != null)
                                ? select.getKeyFinish().getByteBuffer(keyType,variables)
                                : null;

    RowPosition startKey = RowPosition.forKey(startKeyBytes, p), finishKey = RowPosition.forKey(finishKeyBytes, p);
    if (startKey.compareTo(finishKey) > 0 && !finishKey.isMinimum(p))
    {
        if (p instanceof RandomPartitioner)
            throw new InvalidRequestException("Start key sorts after end key. This is not allowed; you probably should not specify end key at all, under RandomPartitioner");
        else
            throw new InvalidRequestException("Start key must sort before (or equal to) finish key in your partitioner!");
    }
    AbstractBounds<RowPosition> bounds = new Bounds<RowPosition>(startKey, finishKey);

    IDiskAtomFilter columnFilter = filterFromSelect(select, metadata, variables);
    validateFilter(metadata, columnFilter);

    List<Relation> columnRelations = select.getColumnRelations();
    List<IndexExpression> expressions = new ArrayList<IndexExpression>(columnRelations.size());
    for (Relation columnRelation : columnRelations)
    {
        // Left and right side of relational expression encoded according to comparator/validator.
        ByteBuffer entity = columnRelation.getEntity().getByteBuffer(metadata.comparator, variables);
        ByteBuffer value = columnRelation.getValue().getByteBuffer(select.getValueValidator(metadata.ksName, entity), variables);

        expressions.add(new IndexExpression(entity,
                                            IndexOperator.valueOf(columnRelation.operator().toString()),
                                            value));
    }

    int limit = select.isKeyRange() && select.getKeyStart() != null
              ? select.getNumRecords() + 1
              : select.getNumRecords();

    List<org.apache.cassandra.db.Row> rows = StorageProxy.getRangeSlice(new RangeSliceCommand(metadata.ksName,
                                                                                              select.getColumnFamily(),
                                                                                              null,
                                                                                              columnFilter,
                                                                                              bounds,
                                                                                              expressions,
                                                                                              limit),
                                                                        select.getConsistencyLevel());

    // if start key was set and relation was "greater than"
    if (select.getKeyStart() != null && !select.includeStartKey() && !rows.isEmpty())
    {
        if (rows.get(0).key.key.equals(startKeyBytes))
            rows.remove(0);
    }

    // if finish key was set and relation was "less than"
    if (select.getKeyFinish() != null && !select.includeFinishKey() && !rows.isEmpty())
    {
        int lastIndex = rows.size() - 1;
        if (rows.get(lastIndex).key.key.equals(finishKeyBytes))
            rows.remove(lastIndex);
    }

    return rows.subList(0, select.getNumRecords() < rows.size() ? select.getNumRecords() : rows.size());
}