Document max-rows-per-poll for the JDBC Gateway

StackOverflow https://stackoverflow.com/questions/45611037

spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/JdbcOutboundGateway.java

@@ -92,16 +92,12 @@ public class JdbcOutboundGateway extends AbstractReplyProducingMessageHandler im
 
 	/**
 	 * The maximum number of rows to pull out of the query results per poll (if
-	 * greater than zero, otherwise all rows will be packed into the outgoing
-	 * message).
-	 *
+	 * greater than zero, otherwise all rows will be packed into the outgoing message).
 	 * The value is ultimately set on the underlying {@link JdbcPollingChannelAdapter}.
-	 * If not specified this value will default to <code>zero</code>.
-	 *
+	 * If not specified this value will default to {@code 1}.
 	 * This parameter is only applicable if a selectQuery was provided. Null values
 	 * are not permitted.
-	 *
-	 * @param maxRowsPerPoll Must not be null.
+	 * @param maxRowsPerPoll the number of rows to select. Must not be null.
 	 */
 	public void setMaxRowsPerPoll(Integer maxRowsPerPoll) {
 		Assert.notNull(maxRowsPerPoll, "MaxRowsPerPoll must not be null.");

src/reference/asciidoc/jdbc.adoc

@@ -274,6 +274,12 @@ The reply message is then generated from the result, like the inbound adapter, a
     data-source="dataSource"/>
 ----
 
+[IMPORTANT]
+=====
+By default the component for the SELECT query returns only one, first row from the cursor.
+This can be adjusted with the `max-rows-per-poll` option.
+Consider to specify `max-rows-per-poll="0"` if you need to return all the rows from the SELECT.
+
 As with the channel adapters, there is also the option to provide `SqlParameterSourceFactory` instances for request and reply.
 The default is the same as for the outbound adapter, so the request message is available as the root of an expression.
 If `keys-generated="true"` then the root of the expression is the generated keys (a map if there is only one or a list of maps if multi-valued).