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I have had some success stealing the immutability ideas out of Datomic and sticking them into normal RDBMs. I generally add a timestamp and a deleted flag to n

by tom_b 10y ago

I have had some success stealing the immutability ideas out of Datomic and sticking them into normal RDBMs. I generally add a timestamp and a deleted flag to normal entities in the schema. Updates or deletes result in new tuples with later timestamps - in the case of deletes a "deleted" column gets updated to 'Y'. All read queries are actually executed against views defined on top of the entities where the max(timestamp) is used to select the most recent instance of an entity along with a check for deleted='N'. If the most recent tuple for an instance has been deleted, it won't show up in the results. This actually works pretty well, but I have a REST API fronting the whole setup - programs are not directly accessing the underlying table or views directly.

shady_lady_768 10y ago
> but I have a REST API fronting the whole setup Have overheard of this in passing. Might elaborating on setup/use-case? Seems strange to me for someone to restrict themselves artifically and not expose the whole power of SQL etc..
- tom_b 10y ago
  Requirements were to allow internal and external teams the ability to CRUD a small set of resources using multiple programming languages, OS, and include command line scripting ability. Direct access to our HIPAA/IRB database instances are based on white-lists - most internal and all external teams are prohibited from direct database connections. So for those groups, there is no possibility of any SQL access to schemas. We use API keys with a shared secret (like AWS) to sign REST requests. If internal and external groups need to work together to jointly CRUD some resources for a specific project, they can share an API key dedicated to that project. There was also a push to switch from an app-centric view of data management to an API-driven approach serving hypermedia (collection+json). That worked conceptually, but most API users ignore the embedded hypermedia links. I find that too bad, as those links make generic API consumption clients much more resilient to change - following a link embedded in a response rather than relying on POST to a well-known URI is a useful abstraction.

by tom_b 10y ago

shady_lady_768 10y ago

> but I have a REST API fronting the whole setup Have overheard of this in passing. Might elaborating on setup/use-case? Seems strange to me for someone to restrict themselves artifically and not expose the whole power of SQL etc..

tom_b 10y ago
Requirements were to allow internal and external teams the ability to CRUD a small set of resources using multiple programming languages, OS, and include command line scripting ability. Direct access to our HIPAA/IRB database instances are based on white-lists - most internal and all external teams are prohibited from direct database connections. So for those groups, there is no possibility of any SQL access to schemas. We use API keys with a shared secret (like AWS) to sign REST requests. If internal and external groups need to work together to jointly CRUD some resources for a specific project, they can share an API key dedicated to that project. There was also a push to switch from an app-centric view of data management to an API-driven approach serving hypermedia (collection+json). That worked conceptually, but most API users ignore the embedded hypermedia links. I find that too bad, as those links make generic API consumption clients much more resilient to change - following a link embedded in a response rather than relying on POST to a well-known URI is a useful abstraction.