Running a delta read

Call the startDeltaRead() method to create a cursor for a delta (incremental) read to be consumed by the readRecords() method.

To run a delta read:

  1. Create a connection to a Record Store server by calling the create() method: 

    RecordStoreLocator locator = RecordStoreLocator.create(host, port, instanceName);

  2. Create a Record Store instance by calling the getService() method: 

    RecordStore recordStore = locator.getService();

  3. Start a READ transaction by calling the startTransaction() method: 

    TransactionId transactionId = recordStore.startTransaction(TransactionType.READ);

  4. Create a ReadCursorId object by calling the startDeltaRead() method: 

    ReadCursorId readCursorId = recordStore.startDeltaRead(transactionId, startGeneration, endGeneration);

  5. Loop over the records returned by readRecords() until all records from the read cursor are read: 

    List<Record> records;

do {

    records = recordStore.readRecords(readCursorId, numRecordsPerFetch);

    // do something with the records

} while (!records.isEmpty());

  6. End the READ transaction by calling the endRead() method: 

    recordStore.endRead(readCursorId);

  7. Commit the transaction by calling the commitTransaction() method: 

    recordStore.commitTransaction(transactionId);

Example 3. Example of running a delta read

RecordStoreLocator locator = RecordStoreLocator.create(host, port, instanceName);

RecordStore recordStore = locator.getService();

TransactionId transactionId = recordStore.startTransaction(TransactionType.READ);

ReadCursorId readCursorId = recordStore.startDeltaRead(transactionId, startGeneration, endGeneration);

List<Record> records;

do {

    records = recordStore.readRecords(readCursorId, numRecordsPerFetch);

    // do something with the records

} while (!records.isEmpty());

recordStore.endRead(readCursorId);

recordStore.commitTransaction(transactionId);


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