Clojurians Log v2

hi, how could I update the value of an attribute by applying a function on it, like in a Clojure atom, instead of just replacing it with a new value, thanks

https://docs.datomic.com/cloud/transactions/transaction-functions.html is maybe what you are looking for

You could also do [:db/cas …], in which you specify your expected old value, as well as the new one. E.g. “If the account balance was 6 euros, then the account balance should now become 9 euros”. If you expectancy is not met, you’ll get an exception.

@danie thanks for the quick reply ! it seems so, but perhaps a bit too compact for someone new to Datomic like me, I'd need a clearer, complete example, thanks

@lennart.buit thanks for your quick reply ! what I am trying to implement is just apply a function to current value and get that replaced by that function application's output

Yeah, you can do that, just pull the current value, apply your function, and compare-and-swap old to new.

https://docs.datomic.com/on-prem/best-practices.html#optimistic-concurrency

Datomic 1.0.622 On-Prem now available: https://forum.datomic.com/t/datomic-1-0-6222-now-available/1700

What's the recommended solution, if there is one, for free form text search across multiple attributes? Bonus points for different matching algorithms and weighted results. Has anyone attempted to integrate Datomic with Elasticsearch? Thanks

Well, I'd say Elasticsearch is indeed a good choice, giving you a lot of flexibility for text search across multiple attributes straight out of the box.

There shouldn't be any issues with using Elasticseach with Datomic if you use the standard practice of storing your data in a real database (eg. Datomic) and only using Elasticsearch as a secondary view to the data.

I’m trying to use dev-local to write a test that involves a datomic database. I can open the connection and get a database, but when my code is done running, the program waits for about 30-40s before it completes. Presumably this is because I’ve failed to shut down something related to datomic, but I cannot figure out how to close the connection or otherwise shut down the dev-local database. (Note: if I never call datomic.client.api/connect, the program shuts down immediately)

Here is my code:

#!/bin/sh

#_(
#_DEPS is same format as deps.edn. Multiline is okay.
   DEPS='
   {:deps {com.datomic/dev-local {:mvn/version "0.9.225"}
           }}
   '
#_You can put other options here
   OPTS='   
   '

exec clojure $OPTS -Sdeps "$DEPS" "$0" "$@"
   )

(require '[datomic.client.api :as d]
         '[datomic.dev-local :as dl]
         '[clojure.test :as ct :refer [is testing deftest use-fixtures]])

(deftest datomic-integration
  (let [args {:server-type :dev-local
              :system "test"
              :db-name "movies"
              }
        client (d/client args)
        _ (d/create-database client args)
        ;; If I don't call connect, the script exits immediately after
        ;; the tests run.
        conn (d/connect client args) 
        ]

    (println (class conn)) ;; datomic.dev_local.impl.DurableConnection
    
    (dl/release-db args)

    (is (= 1 1))))

(ct/run-tests)

If a clojure process is idle for 60 seconds before shutting down, it’s almost always the agent thread pool

try (shutdown-agents) at the end

Works perfectly, thank you!!!!

understood, thanks

understood, thanks