i'm new to this DBA field, so i may sound childish when i ask this question. What is the daily work of a DBA? What is the daily routine work of an Oracle DBA? i hope many DBA gurus would share their experience. Thanks in advance
I think if you're doing the same thing every day, there's a big problem. Who wants to spend their life checking log files and running the same old scripts on the database? If you end up doing something more than three times, automate it. I think the last time I looked at an alert.log was three years ago. I automated the process so when something of interest pops up, I get an alert. I have a script that watches free space in the database and knows when and where to add a datafile should the need arise.
Your worth as a DBA increases when you can solve problems, not check items off a list.
Try looking up performance tuning at http://tahiti.oracle.com. How you do proactive tuning depends on the version of Oracle you are using. But generally look a turning on sql_trace using the set events 10046. If you have access to OEM either the locally installed version that exists through version 10g or the web based version in 10g and 11g you should be able to find things that need tuned. Tuning is a big subject and it really depends on the database and application you are using.