When to Begin using SQL / MySQL

I apologize if this question is vague. I am a very new server operator, and could not find this general piece of information here on the forums.

I am running a low end public Ubuntu box (2GB memory) and am very performance conscious because I am budget conscious. I've been learning to java-profile to reduce memory and processor use, and staying away from plugins that eat a lot of CPU and memory.

My question, and this may be too general to answer, is about plugins that support SQL / MySQL. I am comfortable with and capable of setting up and managing a MySQL server on the same box my server is running. Every plugin I have at this time is SQL capable, but does not require it.

Are there any considerations I need to keep in mind before setting up MySQL and switching my plugins over to use it? Is this just a "You should definitely do it if you can." thing, or are there definite pros and cons, e.g memory vs. CPU vs. disk writes trade-offs? Is it possible that my server would be better off sticking to .yml storage until it grows to a particular size, or is .yml mostly inferior?

I know that is a very general question, but I'm looking for a general answer, a rule of thumb. I'll explain some of the plugins I am using or am considering using, in case it helps, but I'm just looking for general opinions if possible. I'm not planning on making any of my own plugins at this time, so this is not really a development question.

I'll be using Multiverse, MV Portals, and MV Inventories. I'm currently using PermissionsEX, and I'll most likely be using Towny and WorldGuard for player and admin protections. I hope to implement one of the more popular economy plugins, and possibly something that allows me to have fine control over mob strength and drops, but I haven't settled on anything yet. I'm also considering a block durability plugin. I'm not sure which of these will support SQL, but those are all the plugins that seem like they would need to store a lot of data.

Thank you in advance for any advice you can give me!

 

@Disgusie

The only time i have ever found mysql beneficial is if you are running the database off of another drive . Other then that me personally i don't notice any difference with it running on the same drive as the main server . I run my server from a ssd and the database off of 2 2tb drives in raid 0 just in case something happens i want lose any data . I also like mysql because i use a few nice web gui's that hook into my database and display the info in a pretty gui on my site .

 

You should use MySQL for a plugin which writes a lot of data. For example, Prism or any other block logging plugins. My Prism database has 2 million rows and occupies 250 MB.

Most other plugins do not write that much data and are better using flat files or whatever they want to do.

A special case is WorldGuard. Do NOT use MySQL with WorldGuard. Its MySQL implementation is buggy (or so I've been told).

 

Thanks much for the tips!

I assume I'm going to take an automatic memory hit when I install my first plugin that requires MySQL. I guess I should just install a MySQL block-logger now and see what I lose.