Dear Seniors, I am a junior DBA and last weekend I attended a interview for DBA post. The following questions were asked to me and I could not able to answer to the employers satsifaction. He asked me around 20 questions and the following are the questions where I have not fared well. Could Seniors help me by giving the appropriate answers for the following questions :
1) When you enter 'sqlplus scott/tiger' which background process checks for authentication ? From which table/view it checks for authentication ? If password is wrong from where oracle throws the msg ? (I told server process, but could not remember the dictionary file and error msg file) 2) If you create a permanent tablespace and allot it to 5 users as temporary tablespace, how many extents will be allocated by oracle for each user ? (I answered that initial and next extent values will be alloted to the user. The employer told that my answer is not upto the mark) 3) When redo log contains both roll forward and rollback entries, why you require a separate rollback segment ? (I told that redo files are fixed in size and will be overwritten for large transaction, whereas rbs will grow to accommodate the entire transaction if autoextend is on and space is available) 4) When you insert or import 8 GB of data and your rollback segment is of 100 MB size (without autoextend), then what will happen to the transaction ? During inserts or import what entries will goto rollback segment ? (I told rbs has nothing to do with insert or import) 5) When deferred rollback segment is used ? ( I could not able to answer this question) 6) Is it possible to change ownership of Process IDs from oracle to the user who have invoked the process (for example all scott user processes are owned by Oracle user when you check in unix ps -ef |grep oracle command). Why the PIDs are owned by Oracle instead of the user who has invoked it ? (I answered - because the listener starts the process, the ownership is showing as oralce instead of the actual user. I could not able to answer how to change the ownership) 7) What are the other reasons for ORA-1555 error except rbs size is small ? 8) After starting database, where will the dictionary files will reside (memory or system tablespace datafile). If your answer is memory, then whether all the v$ and x$ and other dictionary files are loaded in memory ? ( I answered that it depeneds upon the size of SGA). 9) Where freelists are stored ? (I told that it is stored in datafile header) 10) Is 'direct_io' parameter is equal to raw device (I answered that to some extent it is true). Thanks in advance. Dharan. __________________________________________________ Do You Yahoo!? Send your FREE holiday greetings online! http://greetings.yahoo.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Dharani Ravi INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
