How php implements solutions for large databases

Php uses PHP + mysql for websites of large database companies. However, I know that many of the company's information needs to be queried from the website and financial report data, the operation department's performance query is all found in it, and the data storage time is two years, I am thinking that such a large database MYSQL should not be competent. Why can companies achieve this ?? I only know how the company's server is LIUNX php to implement large databases
The company's website uses PHP + mysql, but as far as I know, the company has a lot of information to query from the website, financial report data query, the operation department's performance query is all found in it, and the data storage time is two years, I am thinking that such a large database MYSQL should not be competent. Why can companies achieve this ?? I only know that the company's server is a LIUNX server. please help me solve my regret. What technologies are they using and how they are learned. I am also an expert on PHP.

------ Solution --------------------
The data size of a database is measured by XXX rows of data in a single table.
Generally, the processing capacity of a database is measured by the number of queries processed per second (read/write)

The maximum data size of a single table depends on the physical performance of the machine (mainly because the maximum number of single files supported by the disk partition format, for example, FAT32 is 4 GB, and others are several TB of data ), mysql documentation says some companies use mysql to support hundreds of millions of data records in a single table, and some Chinese companies have heard of hundreds of millions of data records in a single table. this has not been verified, however, when we run millions of records on a personal PC, MSSQL is also a 0.5 million-level database, which is not necessarily comparable to performance MS, however, databases such as MS and oracle have a strong SQL parsing engine, which makes it easier to solve more complex business logic.

In short, there is no problem with tools. it mainly depends on how people who use tools use this tool. I believe that the average company's business and financial services have been dealing with things in the same way for two years.
------ Solution --------------------
Discussion

Oracle... MSSQL... except for schools and state-owned enterprises... enterprises with less than people cannot afford license ....

LZ you are too small to look at mysql. as long as the database structure is properly designed and optimized, it is okay to have a single table with a billion levels.

A 3G small table at hand
Rows: 3740064384