Currently I am using celery to build a scheduled database synchronization feature, which periodically fetch data from multiple databases. If I want to store the task results, would the performance be better if I store them in Redis instead of a RDB like MySQL?
Performance-wise it's probably going to be Redis but performance questions are almost always nuance based.
Redis stores lists of data with no requirement for them to relate to one another so is extremely fast when you don't need to use SQL type queries against the data it contains.