It was an 'exercise' for evaluation purpose. In the instructions I was told that a database was not necessary (I'm assuming the interviewer didn't want to have to setup a DBMS just to evaluate my solution).
The obvious solution to me in this case was not to eschew the use of a database. Since Clojure runs on the JVM, there are many 'embeddable' databases one can use (H2, Derby, et al) that do not place a burden on the person running your program. Hacking together a poor implementation of an in-memory database myself seemed silly.
Indeed, a major use of embedded databases like H2 and Derby is in prototyping - with the intent of moving to a 'real' database in production.
The obvious solution to me in this case was not to eschew the use of a database. Since Clojure runs on the JVM, there are many 'embeddable' databases one can use (H2, Derby, et al) that do not place a burden on the person running your program. Hacking together a poor implementation of an in-memory database myself seemed silly.
Indeed, a major use of embedded databases like H2 and Derby is in prototyping - with the intent of moving to a 'real' database in production.