The journey of an Oracle DBA is not always a safe journey in Sea. There will be a lot of problems facing him on his daily job schedule. Oracle Database can also crash at any time due to power failures, unexpected natural disastrous and may be also due to a programmer error. He have to make sure the he be always having the following things with him.
1) Gold Copy of a Database
Gold copy of a database is database backup at the starting stage of the product.
2) Relevant Backup in tape or drive
Relevant backup that he can recover the entire data at the time of disasters
3) Sample scripts for common requirements like adding a data file, creating a user, performing a backup from backend, trouble shooting scripts etc.
4) Always practice the commonly performed scripts and try to remember the table names like v$tables.
Most Common issue oracle DBA will face from end users is that they will say database is slow.
In the case an Oracle DBA need to make sure that
1) Entire database is slow (OR)
2) Some users are encounter slow (OR)
3) Only one session is slow
If you found that Entire database is slow means,
You need to look into CPU and Memory and I/O, etc….
If you found that some users are experiencing issues means,
a) Check what those sessions are running
if all sessions are accessing same objects at same time obviously all sessions will slow if those are doing DML,check for session locks or dead locks.
ii) Check stats, index of selected tables.
b) Check for those network usage
i) There may be a chance network may be slow