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@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 🙂


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.