@antonmos This is your fault! 🙂

(deftest fold-rs-test
  (let [ds-opts (jdbc/with-options (ds) (default-options))]
    (testing "foldable result set"
      (let [result
            (r/fold 2 r/cat r/append!
                    (r/map (column :FRUIT/NAME)
                           (jdbc/plan ds-opts ["select * from fruit order by id"])))]
        (is (= 4 (count result)))
        (is (= "Apple" (first result)))
        (is (= "Orange" (last result)))))))

(it could just be r/foldcat but I needed a batch size of 2 to verify it was actually doing the work on multiple threads!)

This is on the foldable branch -- and it is only implemented for plan on a DataSource but by the end of the weekend, it'll be fully implemented and documented and released I expect 🙂

Nice!!

Thank you!

Implemented for plan on every data type now, with tests, and documentation. There's definitely some caveats to using this for very large data sets since there's no back pressure here -- it's possible for a very large data set to be read in faster than the reduction of batches can keep up.

FYI, the multi-rs branch has been merged to develop now and documentation added about the :multi-rs true option. I'll be cutting a 1.1.x release in the next few days, but would appreciate some folks trying the latest SHA for develop: {:git/url "" :sha "1ee2238df878fc9b07843e84ae8e8aa0cf0e3c50"}

Changes since the 1.0.478 release currently include: * Address #125 by making the result of plan foldable (in the clojure.core.reducers sense). * Address #124 by extending next.jdbc.sql.builder/for-query to support :`top` (SQL Server), :limit / :offset (MySQL/PostgreSQL), :offset / :fetch (SQL Standard) -- for find-by-keys. * Address #116 by adding a :multi-rs option to execute! to retrieve multiple result sets, for example from stored procedure calls or T-SQL scripts. * Allow :all to be passed into find-by-keys instead of an example hash map or a where clause vector so all rows will be returned (expected to be used with :offset etc to support simple pagination of an entire table). * Add :columns option to find-by-keys (and get-by-id) to specify a subset of columns to be returned in each row. This can also specify an alias for the column and allows for computed expressions to be selected with an alias. It's a lot of new stuff, hence the 1.1.x release, but I would appreciate some additional community testing, if anyone can spare some time.