Data contains a lot of content to go, generally divided into development and management (i.e., operation and maintenance), the two need to master things differ greatly, the former need to understand the writing of sql, stored procedures, triggers, functions, program tuning, such as the development of coarse concepts to understand the database content mechanism; the latter need to master the internal mechanism of the database, and to be proficient, including the operating system should be familiar with, because the relationship between the database and the operating system, the database and the operating system should be relatively familiar with the database, because the database and the operating system. Because the relationship between the database and the operating system is very close, each database internal mechanism is very different, even if a database of different versions of the differences are sometimes very large, in addition to the DBA also need to master sql scripts and shell scripts, linux and other operating system knowledge, these are helpful in managing the database, there are also dba with the front-end developers need to communicate, so the dba also need to know the development interface and so on. dba also need to know the development of interfaces and other knowledge, so a good dba is very comprehensive, because in large companies, dba is often the core of the enterprise, but not overstated or even a large project success or failure of the deciding factor.
sql language is collection-oriented, it is structured language, sql is a relational database standard query language, different databases between the sql syntax is much the same, it has the data query, definition, operation, control functions (these functions need to be permissions to obtain).
Write this first, do not understand and then ask.