hello 👋 how does datomic licensing work with regards to development and staging? Can we use the same license as in production for these environments?

@mkvlr Yes, all Datomic licenses provide unlimited staging/test/dev environments; you can and should use the same key for those envs

@marshall ah great, thanks!

for dev we connect to our staging datomic db (unnecessary context) , and I just started seeing this when attempting to connect

> ActiveMQNotConnectedException AMQ119010: Connection is destroyed org.apache.activemq.artemis.core.protocol.core.impl.ChannelImpl.sendBlocking (ChannelImpl.java:325)

anyone know right off the bat what might be going on? I can ssh into the datomic server and the service appears to be running

ha! nevermind. critical failure in the datomic log. lol

hi there - i was hoping someone could shed some light on what the expression clause ground does

when would i use that versus, say, a parameter binding to a value i know before issuing the query

what effect does it have on query compilation?

I use ground when dealing with constants. I don’t know effects on compilation. The docs mention that ground enables query optimizations

yeah, i think luke might be wondering how is it different than passing constant values in via the :in portion of the query?

yeah, I followed

I guess I mean. If a value is truly constant, why parameterize for it?

sorry. maybe I’m just missing the question entirely.

sure, but then why is ground necessary at all?

just trying to build intuition

Certainly, I would be curious to know if a grounded binding is optimized over a parameterized binding. I sorta assumed that was the case, but I don’t have a clue about that. At the very least, I like it’s expressiveness, because a parameter to me implies something that can change

necessary i mean versus inlining a constant

I made an account on my-datomic, downloaded datomic-free-0.9.5561.56 and then ran the command to start it up from the datomic tutorial at http://docs.datomic.com/getting-started/connect-to-a-database.html: bin/run -m datomic.peer-server -h localhost -p 8998 -a myaccesskey,mysecret -d hello,datomic: and i'm getting the following stack trace:

~/projects/datomic/datomic-free-0.9.5561.56$ bin/run -m datomic.peer-server -h localhost -p 8998 -a myaccesskey,mysecret -d hello,datomic:
Exception in thread "main" java.io.FileNotFoundException: Could not locate datomic/peer_server__init.class or datomic/peer_server.clj on classpath. Please check that namespaces with dashes use underscores in the Clojure file name.

has anyone seen this before?

or know how i can follow along with the tutorial?

ah. apparently the free version of datomic is not amenable to the official datomic tutorial?

that seems like a pretty big barrier to learning

@dpsutton I stumbled upon this issue when I got started with Datomic, managed to fix it after a bit of headache, and now forgot what the solution was

😄 sorry

They want you to use the starter-pro version, not free. Free is basically for use after you already know what you are doing, have the limitations in mind, but specifically need no-cost redistributable licensing. (e.g. you are running lots of small open-source sites)

@favila does free allow for persistence?

yes

it's the same as the dev transactor

@dpsutton Datomic Pro Starter is no cost and supports running peer-server

it is intended as the ‘getting started’ entry to Datomic

but it begins a 1 year license and then you're done. i just want a playground with no strings or penalties which i don't consider this version

perhaps in the future i'll make something and wish i still had this license. i'm trying to follow the official tutorial and its offputting that i begin a 1 year trial rather than just using their free no-strings version

it was also offputting that i had to enter some (poorly validated) personal data just to try it as well

@dpsutton the tutorial uses the datomic client API, but you can experiment with the datomic peer api

e.g. http://docs.datomic.com/dev-setup.html

“Using the Datomic peer library”

I do agree the documentation is pretty bad for newcomers though

that's why it would be nice to follow along with a nice tutorial directly from the people who make it 🙂