As the internet and mobile internet develop, each institution needs to support much more data than it used to. This demand has stimulated the emergence of a large number of data-processing technologies in the it sector, one of which is nosql. Flexible data types, efficient processing capabilities, have allowed nosql to take up a place in the data management system, such as the humans nosql database, mongodb. However, in wix engineering practice, they found that in a large number of scenarios, instead of nosql, mature rdbms were more effective, such as mysql. Following is the sharing of wix project manager aviran mordo, translated by oneapm engineer。
Below is the translation
The developers generally choose the nosql database on the basis of subjective assumptions, or the erroneous idea that “relative database performance is not as good as the nosql database”. In addition, when selecting databases, developers often ignore the cost of transportation. Indeed, according to wix, in most cases it was not necessary to select the nosql database and, if properly used, mysql could be an excellent nosql database。
An important consideration in the construction of an extended system is the maturity of the technology used, and the choice of a mature technology means that it can be recovered quickly when the error occurs. Of course, developers can also use the latest and best nosql database in the project, which in theory can also function well, but how long does it take to recover from problems in the production environment? The accumulation of knowledge and experience that is technically available is crucial to the mitigation of the problem, although it also includes elements that google can search for. By contrast, the relationship database has been in existence for more than four decades and industry has accumulated considerable experience in maintaining the relationship database. On the basis of these considerations, mysql is usually chosen for the technical selection of new projects, rather than for the nosql database, unless it really has a very, very obvious advantage, such as that too much data is not suitable for mysql。
It must be acknowledged that mysql has its own problems. Use in large-scale systems may encounter performance problems. In order to optimize mysql performance, a number of lessons have been learned, including the avoidance of database-level services. As services require a lock on the database, this affects database performance. Normally, the logical application level lock is used to replace it, thereby reducing the load and obtaining a better performance。
Take, for example, the structure of invoices. If an invoice has multiple line items instead of writing all line items on a single service, it should be written on a non-service basis. After all rows are written into the database, a first record will be written here, which contains a pointer for all line items id. In this way, if one of the rows fails to write, the first record of the line will not exist and the whole matter will fail. While this may result in some waste records, it is clearly not a big problem today that storage media are so cheap that they can be regularly deleted。
Some mysql practical experiences are also brokered below:
In wix, mysql is often stored as a key value, for example, by storing json objects in a column, thereby extending the data structure mode without changing the database pattern. In mysql, reading with the primary key is also fast, and wix obtains submarisecond reading speed in this way, which can support the entire use scene. For these reasons, mysql can well be considered as a nosql database that is consistent with acid principles. As for the size of the database, one mysql example supports hundreds of millions of data without difficulty。
A distinct advantage of a relationship database is that it does not take into account eventual consistency, which is not originally supported in the nosql database. Nor is this paper demeaning nosql because relationship databases are already very restrictive: strict data structure and size limits. Just to remind developers not to lose sight of the costs of transportation when choosing new technologies。
Original link: mysql is a great nosql databI'm sorry
