Hi! How do I append data to a cardinality/many datom? Do I have to fetch it first, append it then transact it? I am using Datomic Ions.

@hadilsabbagh18 https://docs.datomic.com/on-prem/transactions.html#cadinality-many-transactions

You just transact a vector containing the new things you want to add.

It does not replace the value, in conj’s those new value onto the existing collection.

Thanks @joe.lane! Should I be reading the on-prem docs as well as the cloud docs?

I’ve often asked myself that question haha. For fundamental things like the above I think its ok. There will be some subtleties. Usually I look at Cloud docs, then on-prem docs if I can’t find something in the Cloud docs.

Good to know @joe.lane! I will use that approach.

@hadilsabbagh18, you definitely want to watch the day of datomic talks which cover the core information model, which is the same in both onprem and cloud

Good suggestion @dustingetz. I have watched one of the talks and understand the basics. I need to dive deeper I think.

Say, is it necessary to specify :db/index true on :db.type/ref entities in order to get the backrefs to be indexed?

@timgilbert nope. all ref type attributes are automatically indexed in both directions

👍 Thanks!