Oracle DBA Interview Questions By B G
我先表达一下我做这套题的感受.
这套题我花了很多时间，期间我参考了资料和其他人的答案。题目看似很简单，我是指看上去都不应该不会。但做起来却不那么容
易（指我自己）。我对我的回答并不满意，我希望大家能够不断更正和完善这套答案，这也是我做这套题的初衷。
Joe
06/06/07
1. How many memory layers are in the shared pool?
The shared pool consists of the library cache and the dictionary cache.
2. How do you find out from the RMAN catalog if a particular archive log has been
backed-up?
RC_BACKUP_REDOLOG or
1) backup set
RMAN> list archivelog all | from ... until.....
e.g
RMAN> list archivelog from time 'sysdate-1'
2)backup
RMAN> LIST BACKUP OF ARCHIVELOG FROM SEQUENCE 1437 UNTIL
SEQUENCE 1437;
3. How can you tell how much space is left on a given file system and how much space
each of the file system's subdirectories take-up?
df – report file system disk space usage.
du – summarize disk usage of each file, recursively for directories.
4. Define the SGA and：
System Global Area.
It consists of Shared pool, Large pool, Java pool, Buffer cache, Log buffer,
Nonstandard block size buffer caches, Keep and recycle buffer caches, and Streams
pool.
? How you would configure SGA for a mid-sized OLTP environment?
Suppose only Oracle is running on the server and MTS is chosen for OLTP.
Reserve 10% of RAM for UNIX/Linux or 20% of RAM for Windows. The rest of
RAM is allocated to SGA.
Log_buffer=3M
Large_pool_size: For dedicated Oracle server, 20-30M is enough. For MTS, the
UGA will be here. Estimate parallel connection and MTS server processes.
Java_pool_size=10M
Shared_pool_size: If all the SQL statements that sent to ORACLE are using bind
variable adequately, then 300M is enough in most cases and it should greater than
100M depending on total RAM.
Data buffer: All the rest RAM should be allocated to Data buffer.
