Difference between a FUNCTION, PROCEDURE and PACKAGE

Explain the difference between a FUNCTION, PROCEDURE and PACKAGE. 
A function and procedure are the same in that they are intended to be a collection of PL/SQL code that carries a single task. While a procedure does not have to return any values to the calling application, a function will return a single value. A package on the other hand is a collection of functions and procedures that are grouped together based on their commonality to a business function or application.

Explain the use of table functions. 
Table functions are designed to return a set of rows through PL/SQL logic but are intended to be used as a normal table or view in a SQL statement. They are also used to pipeline information in an ETL process.

Name three advisory statistics you can collect. 
Buffer Cache Advice, Segment Level Statistics, & Timed Statistics

Where in the Oracle directory tree structure are audit traces placed? 
In unix $ORACLE_HOME/rdbms/audit, in Windows the event viewer

Explain materialized views and how they are used. 
Materialized views are objects that are reduced sets of information that have been summarized, grouped, or aggregated from base tables. They are typically used in data warehouse or decision support systems.

When a user process fails, what background process cleans up after it? 
PMON

What background process refreshes materialized views? 
The Job Queue Processes.

How would you determine what sessions are connected and what resources they are waiting for? 
Use of V$SESSION and V$SESSION_WAIT

Describe what redo logs are. 
Redo logs are logical and physical structures that are designed to hold all the changes made to a database and are intended to aid in the recovery of a database.

How would you force a log switch? 
ALTER SYSTEM SWITCH LOGFILE;

Give two methods you could use to determine what DDL changes have been made. 
You could use Logminer or Streams

What does coalescing a tablespace do? 
Coalescing is only valid for dictionary-managed tablespaces and de-fragments space by combining neighboring free extents into large single extents.

What is the difference between a TEMPORARY tablespace and a PERMANENT tablespace? 
A temporary tablespace is used for temporary objects such as sort structures while permanent tablespaces are used to store those objects meant to be used as the true objects of the database.

Name a tablespace automatically created when you create a database. 
The SYSTEM tablespace.

When creating a user, what permissions must you grant to allow them to connect to the database? 
Grant the CONNECT to the user.

How do you add a data file to a tablespace 
ALTER TABLESPACE ADD DATAFILE SIZE

How do you resize a data file? 
ALTER DATABASE DATAFILE RESIZE ;

What view would you use to look at the size of a data file? 
DBA_DATA_FILES

What view would you use to determine free space in a tablespace? 
DBA_FREE_SPACE

How would you determine who has added a row to a table? 
Turn on fine grain auditing for the table.

How can you rebuild an index? 
ALTER INDEX REBUILD;

Explain what partitioning is and what its benefit is. 
Partitioning is a method of taking large tables and indexes and splitting them into smaller, more manageable pieces.

You have just compiled a PL/SQL package but got errors, how would you view the errors? 
SHOW ERRORS

How can you gather statistics on a table? 
The ANALYZE command.

How can you enable a trace for a session? 
Use the DBMS_SESSION.SET_SQL_TRACE or
Use ALTER SESSION SET SQL_TRACE = TRUE;