I am more familiar with this, most of the large site architecture is a step-by-step deployment, the database is basically divided into a number of but basically will not appear in a region of a library, this is also too small look at the ability of the database, large site architecture in the design of the database is generally based on the site architecture to design, for example, a large site has a number of modules each module database amount is relatively large, then the design of the database is basically a module a database, for example, Sina.com channel, basically each channel is a channel, the database is relatively large. Then the design of the database is basically a module of a database, such as Sina channels, basically each channel is a complete sub-projects, each project has its own database, each project even the database is not the only one, there must be a core database, the core database used to store the most important information, such as the pass account, these, in Sina on the The fact is that 51job is not a very big site, and the importance of the page data is not high, unlike some securities site data is so important

But 51Job's database design is still relatively good, the query, the speed is relatively fast, but like 51 such a relatively single function of the site (only on the job hunting) I suspect that it only uses one database