is there a way to restore a db on windows? I'm having no luck whatsoever, it can't recognise the roots. here are some details: https://groups.google.com/forum/#!topic/datomic/YPBFdRl_fI0

We’d like to store audit trail data each time someone updates the value of an attribute on a particular entity (e.g. store the user and datetime for the update). http://docs.datomic.com/best-practices.html#add-facts-about-transaction-entity looks promising for this use-case, but I wanted to double check if that's the recommended best-practice for audit trails. I also wondered if anyone has a more elaborate example of adding and retrieving facts from transactions? We want to render the audit data in the UI when a user hovers over the attribute’s text-field. Is there a way to merge the entity data, and the transaction audit trail data into one query? Or would we have to do it as multiple queries, and merge the results ourselves?

@james You might want to watch the Reified Transactions video here http://www.datomic.com/videos.html

It includes discussion of using transaction metadata for audit trail

I’ll take a look, thank you!

In datomic’s datalog, is it possible to query for entities with an attribute that is a set of references to other entities, where all such entities satisfy some criterion? E.g.... um… all parents whose children all have red hair?

@donaldball Sure. Oh, @val_waeselynck beat me to it 🙂

@donaldball note the logical pattern here: conjunction = negation of the disjunction of the negations

I think I follow, nice, thanks.

@james remember, you don't actually need to get every bit of info from a single query, as with sql dbs

is there a good way to import data from datomic to redshift? the problem I’m solving is allowing people with sql experience to query data

I talked to Rich about it a while back and he suggested Redshift for exposing data to people who only know SQL (vs trying to write a translator from SQL->datalog)

@wei I was thinking about this issue as well. I didn't get very far writing a SQL to datalog DSL. Then I saw Stu's ETL talk and was wondering if you could just run that in reverse

possibly. need to watch that talk

I don't have any experience with Redshift though, so I was just speaking generally. it would be an interesting exercise

Any ideas how to write datomic.Entity with transit? I would like to send entity attributes to a client with transit, but now I have to manually convert it to a map before giving it to transit writer.

I know how to make custome transit/write-handler instances, but I have no idea how to write something so that the receiver can read it as a map without custome read handler.

I'm willing to admit that this might be a terrible idea...

When we are importing data, we mark the transaction entity with an import id to allow us to see which import a given datum came from. But what is the correct way to find entities with a given transaction associated with them? Everything I have come up with so far takes ages on a large base.

Tagging @marshall for when he gets back.