I have been working to learn Mongodb effectively for one week in order to use for my project. In my project, I will store a huge geolocation data and I think Mongodb is the most appropriate to store this information. In addition, speed very important for me and Mongodb responds faster than Mysql.
However, I will use some joins for some parts of the project, and I’m not sure whether I store user’s information in Mongodb or not. I heard some issues can occur in mongodb during writing process. should I use only mongodb with collections (instead of join) or both of them?
In most situations I would recommend choosing one db for a project, if the project is not huge. On really big projects (or enterprises in general), I think long term organizations will use a combination of
But for things of more reasonable scope, just pick the one that does the core of the use case, and use it for everything.
IMO storing user data in mongodb is fine — you can do atomic operations on single BSON documents so operations like “allocate me this username atomically” are doable. With redo logs (–journal) (v1.8+), replication, slavedelayed replication, it is possible to have a pretty high degree of data safety — as high as other db products on paper. The main argument against safety would be the product is new and old software is always safer.
If you need to do very complex ACID transactions — such as accounting — use an RDBMS.
Also if you need to do a lot of reporting, mysql may be better at the moment, especially if the data set fits on one server. The SQL GROUP BY statement is quite powerful.