I have a datalog query that returns 10e6 rows. I wish to process these lazily I've been using the sample datalog function to work on subsets of data at a time but now I'm timing how long the sample takes and I'm not sure its any faster than a simple (take 256 (d/q ...)

Hi. I have problemy with my query: https://pastebin.com/bGRMKfxm it is really small. The error is: Caused by: java.lang.ClassCastException: mount.core.DerefableState cannot be cast to datomic.Connection I don't understand what is wrong with that. Any help? I am using datomic with Luminus framework.

Hi friends, when reading the docs (https://docs.datomic.com/cloud/ions/ions-reference.html#parameters-example) it states NOTE The datomic-shared prefix is readable by any Datomic system. If you want more granular permissions, you can choose your own naming convention (under a different prefix!), and explicitly add permissions to the IAM policy for your Datomic nodes.

Does this mean any datomic system in my aws account or truly that a different org has access to whatever I put under that prefix?

no, only within your account

Thanks @marshall, I know it seemed silly but I wanted to confirm.

@joe.lane take a look at DatomicSharedParams in IAM

it’s a role that gets created

"Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ssm:GetParametersByPath"
            ],
            "Resource": [
                "arn:aws:ssm:us-east-1:879742242852:parameter/datomic-shared/*"
            ],
            "Sid": "DatomicSharedParameters"
        }
    ]

and if you look at the <stack-name>-<region> IAM role you’ll see a similar permission ^ under get-parameters

"Statement": [
        {
            "Action": [
                "ssm:GetParametersByPath"
            ],
            "Resource": [
                "arn:aws:ssm:us-east-1:879742242852:parameter/datomic-shared/*"
            ],
            "Effect": "Allow"
        }
    ]

notice, scoped to ARN

all nodes will get a similar role

I'm attempting to work through the Datomic on-prem tutorial here: https://docs.datomic.com/on-prem/tutorial.html. The example of d/transact throws a ClassCastException for me:

(d/transact
    conn 
    {:tx-data [{:db/ident :red}
               {:db/ident :green}
               {:db/ident :blue}
               {:db/ident :yellow}]})

that tutorial seems wrong to me

unless there’s some newer datomic om-prem API that accepts a map instead of tx data

OK, that was my instinct as well.

I’m running ‘0.9.5561.50’ and I get the same ClassCastException

Thank you.

Yes, I'm running 0.9.5661.

I think that must be a copy/paste error from a tutorial written for the client API https://docs.datomic.com/client-api/datomic.client.api.html

ahh

yes, that’s client syntax

i’ll fix the example. thanks for catching it

oh. actually that tutorial is intended for use with the client lib

based on the prior page that gets you connected with a client

https://docs.datomic.com/on-prem/getting-started/connect-to-a-database.html

a similar walkthrough for using the peer API can be found here: https://docs.datomic.com/on-prem/peer-getting-started.html

@enn ^

the confusion probably came from the URL which contains “on-prem” https://docs.datomic.com/on-prem/tutorial.html

On-prem supports both client and peer API access

ooh, didn’t know that 🙂

Ah, yeah, I just googled "datomic on-prem tutorial" so I didn't see the previous page.