public void bigDataTest() throws Exception {
        int rowsCount = 100_000;
        int colSize = 1024;
        int colCount = 12;

        

        String colValue = "'"+"x".repeat(colSize)+"'";
        String query = "select explode(sequence(1, "+rowsCount+"))," +
                String.join(",", Collections.nCopies(colCount, colValue));

        try (                
                Connection conn = dataSource.getConnection()
        ) {
            PreparedStatement ps = conn.prepareStatement(query, ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
            ps.setFetchSize(1);
            ResultSet rs = ps.executeQuery();

            int count = 0;
            while(rs.next()) {
                if(count++ % 100 == 0) {
                    LOG.info("Count = {}", count);
                }
            }
        }
    }

With -Xmx200m I can read about 50_000 rows and after that I receive "Exception in thread "pool-12-thread-50" Exception in thread "pool-12-thread-1" java.lang.OutOfMemoryError: Java heap space
java.lang.OutOfMemoryError: Java heap space"

The memory picture is classic for OOM:

What can I see in the heapdump: