JDBC/PluginInterfaces

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Plugin interfaces

Batch Query Handler

The batch query handler is used when a client needs to send alot of queries to a server in batch mode. Depending on the client workload there could be places where a better batch query handler could improve performance. Therefore drizzle-jdbc supports pluggable batch query handlers.

First you need to build the actual batch handler, this is done by implementing a small interface:

public interface ParameterizedBatchHandler {
    /**
     * called when a set of parameters are added to a batch.
     * @param query the parameterized query.
     */
    void addToBatch(ParameterizedQuery query);
 
    /**
     * execute the batch using protocol. Return an array of update counts
     * or -2 (Statement.SUCCESS_NO_INFO) if the update count is unknown.
     * @return a list of update counts
     * @throws QueryException if something goes wrong executing the query.
     */
    int [] executeBatch() throws QueryException;
}

Then a factory for creating handlers is needed, this is done by implementing another interface:

public interface ParameterizedBatchHandlerFactory {
    /**
     * Returns a parameterized batch handler. Called every time prepareStatement 
     * is called on the connection.
     * x
     * @return a parameterized batch handler
     */
    ParameterizedBatchHandler get(String query, Protocol protocol);
}

To change out the default batch query handler, this is done:

if(connection.isWrapperFor(DrizzleConnection.class)) {
   DrizzleConnection dc = connection.unwrap(DrizzleConnection.class);
   dc.setBatchQueryHandlerFactory(new NoopBatchHandlerFactory());
}

Look at these files for more information:

Retrieved from "http://drizzle.org/wiki/JDBC/PluginInterfaces"