Q1) How to check opatch applied or not in our Oracle home?
Answer: ./opatch lsinventory 100 GB of database size while applying opatch it will take 30 mins, so 500 GB of database size how much time it will take to apply opatch. Same 30 Mins, We will apply the opatch for oracle binary only not for data.
Q2) What is sqlnet.ora ?
Answer: It is used to security of our database, Privileged IP address only able to access the database.
Q3) what are the different components of physical and logical database structure?
physical: Datafile,Controlfiles, redologfiles.
Logical: Database buffer cache, Redo log buffer cache,Shared pool,large pool
Q4) What is Database Writer (DBWR)?
Answer: It is responsible to writing data from database buffer cache into datafiles.
Q5) What is a listener process?
Answer: It is network connectivity, Application and sql developer tool to access database. Lietener.ora and Tnsnames.ora files are used.
Q6) What is the difference between SPFILE and PFILE?
Answer: Spfile: Server parameter file of binary file, It contains all the information for setting the database initialization parameters. SPFILE permits dynamic changes without requiring you to restart that instance. Pfile: It is text parameter file, information for setting the database initialization parameters.
Q7) What is the purpose of collecting statistics?
Answer: It will help optimizer to generate best execution plan
Q8) What is an Oracle index?
Answer: It is an database object used to increase the performance for retrieval data.
Q9) If the table is fragmented, how would you rebuild it?
Answer: Alter table tablename move, We can analyze the table.
Q10) What are the different tools that are provided by Oracle to assist performance monitoring?
Q11) What is an explain plan and how does it help in optimizing the SQL Query?
Answer: We will check if query is using proper indexes are not. If not we will either create new indexes or can use hints to specify which indexes to use.