[Improve][Postgres-CDC] Update jdbc fetchsize (#6245)

Author: hailin0

seatunnel-connectors-v2/connector-cdc/connector-cdc-postgres/src/main/java/org/apache/seatunnel/connectors/seatunnel/cdc/postgres/utils/PostgresUtils.java

@@ -50,6 +50,8 @@
 /** The utils for SqlServer data source. */
 @Slf4j
 public class PostgresUtils {
+    private static final int DEFAULT_FETCH_SIZE = 1024;
+
     private PostgresUtils() {}
 
     public static Object[] queryMinMax(JdbcConnection jdbc, TableId tableId, String columnName)
@@ -154,7 +156,7 @@ public static Object[] skipReadAndSortSampleData(
                             .createStatement(
                                     ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
 
-            stmt.setFetchSize(Integer.MIN_VALUE);
+            stmt.setFetchSize(DEFAULT_FETCH_SIZE);
             rs = stmt.executeQuery(sampleQuery);
 
             int count = 0;