Oracle 12c gather statistics oracle deep dive

I referred some reference from my favorite Tim Hall blog (ORACLE_BASE) A.Basic of optimizer statistics: – The optimizer cost model relies on statistics collected about the objects involved in a query, and the database and host where the query runs. Statistics are critical to the optimizer’s ability to pick the best execution plan for a SQL statement. Object What influences […]

Redo,Undo,Control file interview questions

Thanks Akhil Mohan. Debasis Maity: 1.Why controlfile and redolog file multiplexed? Control file : A control file is a small binary file that records the physical structure of the database and includes: The database name. Names and locations of associated datafiles and online redo log files. The timestamp of the database creation. The current log sequence number. Checkpoint information. Oracle […]

Oracle user role and privilege interview questions

 Answer Credit:- How we can execute PLSQL without any privilege to change it What are the default user created when Oracle is installed ? Can you create password less user in Oracle ? If yes how ? How we can see the procedure /package body with out having privilege to execute it How we can create password file […]

Database Architecture Interview Questions

What are base tables? When and how they will get created? Ans:-Are read-only tables(Data Dictionary Tables) that hold information about the database. Base tables are own by SYS. When and how they will get created? They get created when the database is built. Why to execute catproc.sql script? Ans:-Used to create and recreate database internal views/procedures/packagess. Primarily used after […]