Tuesday, June 18, 2019

Return Maps

Most Datomic queries return tuples, but sometimes you just want maps.  Today's release of the Datomic Cloud client library adds return maps to Datomic datalog.  For example, the following query uses the new :keys clause to request maps with :artist and :release keys:

[:find ?artist-name ?release-name
 :keys artist release
 :where [?release :release/name ?release-name]
 [?release :release/artists ?artist]
 [?artist :artist/name ?artist-name]]

Running against the mbrainz-sample database, this query returns:

#{{:artist "George Jones" :release "With Love"}
  {:artist "Shocking Blue" :release "Hello Darkness / Pickin' Tomatoes"} 
  {:artist "Junipher Greene" :release "Friendship"}
  ...}

To try return maps, you can


Thursday, May 23, 2019

HTTP Direct for Datomic Cloud



    Datomic Cloud is designed to be a complete solution for Clojure application development on AWS. In particular, you can implement web services as Datomic ions behind AWS API Gateway.

    The latest release of Datomic Cloud adds HTTP Direct, which lets you connect an API Gateway endpoint directly to a Production Topology Compute Group as shown below: 



    HTTP Direct provides better performance and simpler operation than AWS Lambda Proxy Integration. The latter option continues to be supported on the Solo Topology, which does not include the Network Load Balancer required for HTTP Direct.

    To try out HTTP Direct:
    1. Get the latest release of Datomic Cloud.
    2. Work through the HTTP Direct Tutorial.