title: clojure:how to read data in chunk from a file
body: <p>I want to read file out in chuck, and then insert them into database. Since if insert one record a time is slow, so I'd like to insert 1000 records a time, but how to do it using doseq?</p>
  
  <pre><code> (with-open [rdr (io/reader file-name)]
     (doseq [line (line-seq rdr)]
        ;;how to split them in chuck lazily. so that not use too much memory.
  </code></pre>