Investigate DB performance issues

[QuantumDancer]

Even with only a moderate amount of records in the database, we observe long query times when retrieving records from Auditor. With Postgres being used for the database, this is not really expected. We should investigate if we can improve the performance of the DB queries.

There are several possibilities as to why the performance is suboptimal:

• The database architecture could be improved (indices, sharding, etc.)
• The hardware we are using to run the DB is not keeping up (currently running on a VM in an OpenStack environment).

To investigate these issues, we should first design a benchmarking setup that measures the DB performances. Afterward, we can try out optimizations and evaluate them using the benchmark.