Actions with data that have the properties of atomicity, consistency, isolation and Durability is the ACID definition of a transaction. D – Durability is the same model I was talking about: if the data has already been written to disk, then we believe that it is there, recorded securely and Continue Reading

There is an interesting story in German road traffic regulations. If the road narrows, then the rules prescribe to get to the end, and only then rebuild one by one, and the neighboring car must let through. All are rearranged strictly one after another – this sign speaks about it. Continue Reading

Let’s start with the storage layer. Understanding how it works helps to understand what is happening on the higher layers. The storage layer provides: ✓ Concurrency and efficiency. In other words, it is competitive access. That is, when we try to benefit from concurrency, the problem of concurrent access inevitably Continue Reading