Using YAML to replace smaller SQL tables?

Question

Symfony has turned me on to the power of YAML. It used to be default for me to use MySQL to make tables for an ecommerce site of say supported_countries,units_of_measure or sku_conditions. But now, I might prefer using YAML to create a config/countries.yml, config/units.yml or config/skuConditions.yml. So I'm curious -- in situations like this are there an significant performance factors to consider when deciding to parse and analyzing a YAML file ~ vs ~ Querying and Analyzing SQL data?

countries.yml

US:
    code: US
    name: United States
CA: 
    code: CA
    name: Canada 

skuConditions.yml

default-unit: new
units
    new:
        short: new
        long: brand spanking new
        description: never been used.
    open-box:
        short: open
        long: pretty much new
        description: the box has been opened but never used.

Answer 1

I think YAML is very suitable for configuration files, that's the way Symfony uses it, but if your data is changing a lot, you need a database. If you are worried about performance think using a NoSQL database like MongoDB.