Some Terminologies and their meanings!!!

Question 1

AD-HOC

Answer 1

An Impromptu query.

*select statement/asking for something.

Question 2

BLOCK

Answer 2

The smallest unit of storage in an oracle database.

Contains:

• The Header information concerning the block itself.
• A Free Space..aka pct free or %Free reserved for UPDATES of rows in the BLOCK.
• Row Data..aka %Used or Pct. Used reserved for Rows.

Question 3

BUTTLENECK

Answer 3

A system components that limits performance of the system.

Question 4

BUFFER(memory)

Answer 4

Refers to memories used to store data.

Question 5

CACHE

Answer 5

Storage area to provide fast access to to data.

Question 6

CHECKPOINT

Answer 6

I an operation that forces all changed in-memory data blocks to be written out to the disk.

Question 7

CLEAN BUFFER

Answer 7

An unmodified buffer.

Contains no Data.

Question 8

CONCURRENCY

Answer 8

Capability of performing many functions at the same time.

Question 9

DATABASE

Answer 9

Is a set of Data organised for easy access.

**Instance + Physical Files

Instance = SGA + Background Processes.

SGA = System Global Area(Memory Area).

Question 10

DATA DICTIONARY

Answer 10

Set of tables Oracle uses to maintain information of the Database.

Question 11

DBA(Database Administrator)

Answer 11

Responsible for operation, configuration and performance of DATA.

Question 12

RDBMS

Answer 12

Relational Database Management Systems.

Software and collection of tools that manage the Database.

Question 13

DDL

Answer 13

It is Command for the ability of Creation and Modification of Schema objects.

Question 14

DIRTY BUFFERS

Answer 14

Found in the database buffer cache.

Question 15

KINDS OF BUFFER CACHE

Answer 15

There are 3 kinds :

1. Clean.
2. Pinned.
3. Dirty.

Question 16

DML(Data Manipulation Language)

Answer 16

A command that allows you to query and modify Data within existing Schema objects in a Database.

Data Performance Use - Storing information about performance of thee instance.

Function: Retains ONE result.

A set of SQL or PL/SQL statements used together to execute a particular function.

Procedure: Returns many results after ran.

Question 17

SQL

PL/SQL

Answer 17

Structured Query Language.

Procedural Language/ Structured Query Language.

Question 18

PHYSICAL MEMORY

Answer 18

RAM

Question 19

PACKAGE

Answer 19

Is a collection of procedures and functions.

Question 20

QUERY

Answer 20

Is a read only transaction against a Database.

To query, you need a Table NAME.

Always start a Query with “select”

First choose *Column and then the *Values.

Question 21

SCHEMA

Answer 21

Is a collection of OBJECTS associated with the Database.

Schema Objects consists, Clusters, Packages, Indexes, Views, Tables, Synonyms e.tc.

Views are used to secure data.

Question 22

SGA (System Global Area)

Answer 22

Shared memory region that Oracle uses to store Data and Control information for One Oracle instance.

SGA(Memory)=Shared pool | Buffer Cache | Redo log Buffer.

Question 23

VIRTUAL MEMORY

Answer 23

This is part of the hard drive and also a temporal memory.

It is a memory that can be used for programming in an Operating System.

When engaged, slows System up and that is called Paging and Swapping.

Data is copied from memory to the swap space.

Question 24

SQLPLUS

Answer 24

An Oracle utility for connecting into an Oracle Database.

eg: sqlplus *usename/password/@DB connect string.

Logged into a Linux Server as bitechstudent, an O/S user who has no privilege to access the Database. So I must switch user (su -) to one who has access the Database Software ( RDBMS).

su -

enter password oracle11

sqlplus bt/bt (this logs you into the default DB.

desc(ribe) user_tables ( to see all tables owned by the user or schema (bt).

select table_name, NUM_ROWS from user_tables;

[table_name, NUM_ROWS] =Column names

[ user_tables] = table NAME ( Data Dictionary Table)

The select statement issued above will display the NAMES and NUMBER of ROWS of tables OWNED by the current connected USER (bt).

Question 25

DATA STORAGE

Answer 25

Data is stored in binary form.

Binary Data is 0nes and Zeroes.

Units used to refer to are:

1. Bit - Smallest unit of Data Storage.
2. Byte - 8 Bits - most commonly used.
3. Kilobyte - 1024 Bytes.