In most modern websites, the database works continuously. An online store accesses it when the catalog opens, when the shopping cart is formed, or when an order is processed. A CRM pulls client contacts and the history of actions. Even a typical corporate website with a request form sends a query to the database every time. While the number of visitors is small, this is almost invisible. But when the site begins to be actively used, the load shifts precisely to the database. It processes queries, builds result sets, writes new data. If the server environment is limited, the system is usually the first to react. Pages open more slowly, queries execute with delays. Timeouts or limit exceedances appear in the logs. In such situations, the first instinct is often to look for the problem in the code or in the structure of the tables. Sometimes that really helps. But quite often it turns out that the database itself works normally, the server simply was not designed for that volume of queries.
