But now, DBA is not a very good job. Overtime, working hours and salary returns are not high, which is the current situation of DBA occupation. But if you can develop, like Python. Python+DBA can be an operation and maintenance automation engineer, which is very promising. If you consider DBA, I suggest developing in this direction. 35 years old is fine.
Database, it is suggested that Oracle and MySQL are two major databases. At the same time, master the management and operation of these two databases. Of course, you can also choose other databases. These two databases are relatively mainstream.