The database is at the center of the modern software. Most of the software being written today uses databases. Nothing in software is more universal, or more central to everything. Databases have three important characteristics. First, they are huge. Almost everything ever written is stored in a database. Databases hold Continue Reading
Base
ACID transactions
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
Proficiency in code
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
Storage layers
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
Data storage and processing
Even if you have already had a blog on the Internet on text files for 30 years, as some database creators do, in fact, this text file is a database, just a very simple one. Everyone is trying to reinvent the database. One of the speakers at the conference said: Continue Reading
Requirements for the data access layers
It is still important for the storage layer to maintain the original parallelism so that all data is not beaten, overwritten, overwritten, etc. At the same time, they must be securely stored and reliably reproduced. That is, if we write something to the database, we must be sure that we Continue Reading
SQL implementations
First of all, in order to provide universal and optimal access to data, there is a query language. In most cases, this is SQL (why exactly it, we will discuss further), but now I just want to draw attention to the trend. First, there was SQL for a long time Continue Reading