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Code Block
languagejava
titleMultiVersionedRangeQuery
linenumberstrue
package org.apache.kafka.streams.query;


/**
 * Interactive query for retrieving a set of records with keys within a specified key range and time
 * range.
 */

@Evolving
public final class MultiVersionedRangeQuery<K, V> implements
    Query<KeyValueIterator<K, VersionedRecord<V>>> {

  private final Optional<K> lower;
  private final Optional<K> upper;
  private final Optional<Instant> fromTime;
  private final Optional<Instant> toTime;
  private final boolean isKeyAscending;
  private final boolean isTimeAscending;
  private final boolean isOrderedByKey;

  private MultiVersionedRangeQuery(
      final Optional<K> lower,
      final Optional<K> upper,
      final Optional<Instant> fromTime,
      final Optional<Instant> toTime,
      final boolean isOrderedByKey,
      final boolean isKeyAscending,
      final boolean isTimeAscending) {
    this.lower = lower;
    this.upper = upper;
    this.fromTime = fromTime;
    this.toTime = toTime;
    this.isOrderedByKey = isOrderedByKey;
    this.isKeyAscending = isKeyAscending;
    this.isTimeAscending = isTimeAscending;
  }

   /** 
   * Interactive range query using a lower and upper bound to filter the keys returned. * For each 
   * key the records valid within the specified time range are returned. * In case the time range is 
   * not specified just the latest record for each key is returned. 
   * @param lower The key that specifies the lower bound of the range 
   * @param upper The key that specifies the upper bound of the range 
   * @param <K> The key type 
   * @param <V> The value type 
   */ 
   public static <K, V> MultiVersionedRangeQuery<K, V> withKeyRange(final K lower, final K upper);


   /**
   * Interactive range query using a lower bound to filter the keys returned. * For each key the
   * records valid within the specified time range are returned. * In case the time range is not
   * specified just the latest record for each key is returned.
   * @param lower The key that specifies the lower bound of the range
   * @param <K>   The key type
   * @param <V>   The value type
   */
  public static <K, V> MultiVersionedRangeQuery<K, V> withLowerKeyBound(final K lower);

  /**
   * Interactive range query using a lower bound to filter the keys returned. * For each key the
   * records valid within the specified time range are returned. * In case the time range is not
   * specified just the latest record for each key is returned.
   * @param upper The key that specifies the lower bound of the range
   * @param <K>   The key type
   * @param <V>   The value type
   */
  public static <K, V> MultiVersionedRangeQuery<K, V> withUpperKeyBound(final K upper);

  /**
   * Interactive scan query that returns all records in the store. * For each key the records valid
   * within the specified time range are returned. * In case the time range is not specified just
   * the latest record for each key is returned.
   * @param <K> The key type
   * @param <V> The value type
   */
  public static <K, V> MultiVersionedRangeQuery<K, V> allKeys();

  /**
   * Specifies the starting time point for the key query. The range query returns all the records
   * that are valid in the time range starting from the timestamp {@code fromTime}.
   * @param fromTime The starting time point
   */
  public MultiVersionedRangeQuery<K, V> fromfromTime(Instant fromTime);

  /**
   * Specifies the ending time point for the key query. The range query returns all the records that
   * have timestamp <= {@code toTime}.
   * @param toTime The ending time point
   */
  public MultiVersionedRangeQuery<K, V> asOftoTime(Instant toTime);


  /**
   * Specifies the overall order of returned records by timestamp
   */
  public MultiVersionedRangeQuery<K, V> orderByTimestamp();

  /**
   * Specifies the order of keys as descending.
   */
  public MultiVersionedRangeQuery<K, V> withDescendingKeys();

  /**    
   * Specifies the order of the timestamps as descending.
   */
  public MultiVersionedRangeQuery<K, V> withDescendingTimestamps();

  /**
   * The lower bound of the query, if specified.
   */
  public Optional<K> lowerKeyBound();

  /**
   * The upper bound of the query, if specified
   */
  public Optional<K> upperKeyBound();

  /**
   * The starting time point of the query, if specified
   */
  public Optional<Instant> fromTime();

  /**
   * The ending time point of the query, if specified
   */
  public Optional<Instant> toTime();

  /**
   * @return true if the query orders the returned records by key 
   */
  public boolean isOrderedByKey();

  /**
   * @return true if the query returns records in ascending order of keys
   */
  public boolean isKeyAscending();

  /**
   * @return true if the query returns records in ascending order of timestamps
   */
  public boolean isTimeAscending();

}

...

The following example illustrates the use of the VersionedKeyQuery class to query a versioned state store.

Imagine we have the following records 

put(1, 1, time=2023-01-01T10:00:00.00Z)

put(1, null, time=2023-01-05T10:00:00.00Z)

put(2, 20, time=2023-01-10T10:00:00.00Z)

put(3, 30, time=2023-01-12T10:00:00.00Z)

put(1, 2, time=2023-01-15T10:00:00.00Z)

put(1, 3, time=2023-01-20T10:00:00.00Z)

put(2, 30, time=2023-01-25T10:00:00.00Z)

Code Block
languagejava
linenumberstrue
// example 1: MultiVersionedRangeQuery without specifying any time bound will be interpreted as all versions
final MultiVersionedRangeQuery<Integer, Integer> query1 =
        MultiVersionedRangeQuery.withKeyRange(1, 2);
final StateQueryRequest<KeyValueIterator<Integer, VersionedRecord<Integer>>> request1 =
        inStore("my_store").withQuery(query1);
 
final StateQueryResult<KeyValueIterator<Integer, VersionedRecord<Integer>>> versionedRangeResult1 = kafkaStreams.query(request1);
 
// Get the results from all partitions.
final Map<Integer, QueryResult<KeyValueIterator<Integer, VersionedRecord<Integer>>>> partitionResults = versionedRangeResult.getPartitionResults();
for (final Entry<Integer, QueryResult<KeyValueIterator<Integer, VersionedRecord<Integer>>>> entry : partitionResults.entrySet()) {
    try (final KeyValueIterator<Integer, VersionedRecord<Integer>> iterator = entry.getValue().getResult()) {
        while (iterator.hasNext()) {
          final KeyValue<Integer, VersionedRecord<Integer>> record = iterator.next();
          Integer key = record.key;
          Integer value = record.value.value();
          Long timestamp = record.value.timestamp();
		  Long validTo = record.value.validTo();
	      System.out.println ("key,value: " + key + "," +value + ", timestamp: " + Instant.ofEpochSecond(timestamp)+ ", valid till: " + Instant.ofEpochSecond(validTo));  	
        }
     }
}
/* the printed output will be
    key,value: 1,1, timestamp: 2023-01-01T10:00:00.00Z, valid till: 2023-01-05T10:00:00.00Z  
    key,value: 1,2, timestamp: 2023-01-15T10:00:00.00Z, valid till: 2023-01-20T10:00:00.00Z 
    key,value: 1,3, timestamp: 2023-01-20T10:00:00.00Z, valid till: now 
    key,value: 2,20, timestamp: 2023-01-10T10:00:00.00Z, valid till: 2023-01-25T10:00:00.00Z 
    key,value: 2,30, timestamp: 2023-01-25T10:00:00.00Z, valid till: now 
*/

// example 2: The value of the records with key range (1,2) from 2023-01-17 Time: 10:00:00.00Z till 2023-01-30 T10:00:00.00Z


final MultiVersionedRangeQuery<Integer, Integer> query2 =
        MultiVersionedRangeQuery.withKeyRange(1, 2);
query2 = query2.fromTime(Instant.parse(2023-01-17T10:00:00.00Z)).toTime(Instant.parse(2023-01-30T10:00:00.00Z)).orderByTimestamp().withDescendingTimestamps();
 
final StateQueryRequest<KeyValueIterator<Integer, VersionedRecord<Integer>>> request2 =
        inStore("my_store").withQuery(query2);
 
final StateQueryResult<KeyValueIterator<Integer, VersionedRecord<Integer>>> versionedRangeResult2 = kafkaStreams.query(request2);
 
// Get the results from all partitions.
final Map<Integer, QueryResult<KeyValueIterator<Integer, VersionedRecord<Integer>>>> partitionResults2 = versionedRangeResult2.getPartitionResults();
for (final Entry<Integer, QueryResult<KeyValueIterator<Integer, VersionedRecord<Integer>>>> entry : partitionResults.entrySet()) {
    try (final KeyValueIterator<Integer, VersionedRecord<Integer>> iterator = entry.getValue().getResult()) {
        while (iterator.hasNext()) {
          final KeyValue<Integer, VersionedRecord<Integer>> record = iterator.next();
          Integer key = record.key;
          Integer value = record.value.value();
          Long timestamp = record.value.timestamp();
 		  Long validTo = record.value.validTo();
	      System.out.println ("key,value: " + key + "," +value + ", timestamp: " + Instant.ofEpochSecond(timestamp)+ ", valid till: " + Instant.ofEpochSecond(validTo));           
		}
     }
}

/* the printed output will be     
    value: 12,230, timestamp: 2023-01-15T1025T10:00:00.00Z, valid till: 2023-01-20T10:00:00.00Znow 
    value: 1,3, timestamp: 2023-01-20T10:00:00.00Z, valid till: now
     value value: 1,2,30, timestamp: 2023-01-25T1015T10:00:00.00Z, valid till: now     2023-01-20T10:00:00.00Z 
*/


Compatibility, Deprecation, and Migration Plan

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