Massive PHP array vs MySQL Database?

Question

I'm debating in my head whether I should use a massive, multidimensional array or a database in MySQL. I'm developing for a client whose business has many products. In this multidimensional array I would include the product title, description, image link and categories for each individual product.

My client has perhaps 1000+ products. I've researched other similar questions and many of them say that an array is perhaps faster, however none of them are dealing with an array of this scale.

I personally would much rather use an array, because my knowledge with MySQL is extremely limited, but if it means sacrificing a significant amount of speed then I would rather use the database. Which would you consider a more appropriate option for my case?

Answer 1

The other answers are right - but for the wrong reasons.

Holding the data in a PHP array it will be much faster to fetch than from a database - even if the dataset is cached in memory. The issue is that in normal PHP architectures each request is handled by a seperate process. Hence each request which needs access to the data will have to load the entire dataset into memory. This takes time. The point at which it becomes more expensive to perform this operation rather than retrieving items from a database depends on a lot of different factors - but as a rough rule of thumb it's in the region of 100 records. There are applications where this model makes sense - but they rely on very small data volumes and a controlled process of changing / managing the data.

Your next problem is that you'll probably want to record some transactions against the stock - that means changing the data - and that means serializing access to ensure that 2 separate transactions don't happen at the same time. It is impossible to implement this in PHP (without a dedicated daemon to adjudicate) while not having deadlocks.

If you are charging someone for implementing the code, then it should be blindingly obvious that trying to implement this in memory is a very, very bad idea.