[TRAFODION-3183] fetch huge data give rise to core

Author: aven

core/conn/jdbcT4/src/main/java/org/trafodion/jdbc/t4/TrafT4ResultSet.java

@@ -2779,6 +2779,19 @@ public boolean next() throws SQLException {
 					maxRowCnt = maxRows - totalRowsFetched_;
 				}
 
+        // if (row width) * (fetch rows) too large, there will have core in server side.
+        // once fetch bytes bigger than 1GB, devide several times to fetch,
+        // each time fetch bytes less than 1GB.
+        if (outputDesc_ != null && outputDesc_[0] != null) {
+          long rowLength = outputDesc_[0].rowLength_;
+          long oneGB = 1024 * 1024 * 1024;
+          if (rowLength * maxRowCnt >= oneGB) {
+            double multi = (rowLength * maxRowCnt) / (double)oneGB;
+            multi = Math.ceil(multi); // devide several times to fetch
+            maxRowCnt = (int) (maxRowCnt / multi);
+          }
+        }
+
 				if (maxRowCnt == 0) {
 					validRow = false;
 				} else {