1. Database Administration
Rehema Baguma

2. Who is a DBA
A person responsible for designing, implementing, and maintaining the database system; establishing policies and procedures pertaining to the management, security, maintenance, and use of the database management system.

3. Skills for a DBA Communication skills Knowledge of database theory
Knowledge of database design
Knowledge about the RDBMS e.g. Microsoft SQL Server
Knowledge of Structured Query Language (SQL)
General understanding of distributed computing architectures e.g. Client/Server, Internet/Intranet, Enterprise
General understanding of the underlying operating system, e.g. Windows, Linux
General understanding of storage technologies, memory management, disk arrays

4. Roles of a DBA
Installing and upgrading the database server and application tools
Allocating system storage and planning future storage requirements for the database system
Modifying the database structure, as necessary, from information given by application developers verbally
Enrolling users and maintaining system security
Ensuring compliance with database vendor license agreement
Controlling and monitoring user access to the database
Monitoring and optimizing the performance of the database
Planning for backup and recovery of database information
Maintaining archived data
Backing up and restoring databases
Contacting database vendor for technical support
Generating various reports by querying from database as per need

5. Understanding the DBMS Architecture
The database architecture is the set of specifications, rules, and processes that dictate how data is stored in a database and how data is accessed by components of a system.
It describes the organization of all database objects and how they work together.
It affects integrity, reliability, scalability, and performance.

6. Data Model
Data model:   Collection of concepts that describe the structure of a database
Provides means to achieve data abstraction
Suppression of details of data organization & storage

7. Categories of Data Models
High-level or conceptual data models: close to the way many users perceive data
Low-level or physical data models: Describe the details of how data is stored on computer storage media OR
 External; How data is viewed by an individual user
Conceptual: How data is viewed by a community of users
Internal: How data is physically stored

8. Categories of Data Models!

9. Categories of Data Models cont..
Entity
Represents a real-world object or concept e.g. student
Attribute
Represents some property of interest e.g. year of study
Further describes an entity
Relationship among two or more entities
Represents an association among the entities
Entity-Relationship model
Relational data model
Based on relation/table principle for data storage and management

10. Categories of Data Models cont..
Object data model
New family of higher-level implementation data models
Closer to conceptual data models
 Physical data models
Describe how data is stored as files in the computer
 Access path
Structure that makes the search for particular database records efficient
 Index
Example of an access path
Allows direct access to data using an index term or a keyword
A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of slower writes and increased storage space. Indexes can be created using one or more columns of a database table, providing the basis for both rapid random look ups and efficient access of ordered records. The disk space required to store the index is typically less than that required by the table (since indexes usually contain only the key-fields according to which the table is to be arranged, and exclude all the other details in the table), yielding the possibility to store indexes in memory for a table whose data is too large to store in memory.

11. Schemas instances and database State
Database schema
Description of a database
 Schema diagram
Displays selected aspects of schema
 Schema construct
Each object in the schema
 Database state or snapshot
Data in database at a particular moment in time
  Initial state
Populated or loaded with the initial data
Valid state
Satisfies the structure and constraints specified in the schema

12. Example of a Database Schema!

13. DBMS Interfaces Menu-based interfaces for Web clients or browsing
  Forms-based interfaces
Graphical user interfaces
  Natural language interfaces
Speech input and output
Assignment-Using the internet, identify and explain top 10 website security vulnerabilities and how they can be guarded against (work in groups of 5).

14. Database Components Buffer management Stored data manager DDL compiler
DDL compiler is the compiler whose job is to convert high level commands to low level commands..
Interactive query interface
Query compiler
Runtime database processor
System catalog
Concurrency control system
Backup and recovery system

15. DB system Utilities Loading Backup Database storage reorganization
Load existing data files
  Backup
Creates a backup copy of the database
Database storage reorganization
Reorganize a set of database files into different file organizations
Performance monitoring
Monitors database usage and provides statistics to the DBA
Practicals-configure, DB server connection to the web server, location and resetting DBMS logs, backup and recovery, introducing the database index…..Mysql/SQL

16. Centralised Vs Client server DB architectures
Centralized DBMSs Architecture
All DBMS functionality, application program execution, and user interface processing carried out on one machine
 Servers with specific functionalities
File server
Maintains the files of the client machines.
Printer server
Connected to various printers; all print requests by
the clients are forwarded to this machine
Web servers or servers
Client
  User machine that provides user interface capabilities and local processing
 Server
  System containing both hardware and software
  Provides services to the client machines
•  Such as file access, printing, archiving, or database
Access

17. Two Tier, Three Tier and N-Tier
Server handles
Query and transaction functionality related to SQL processing
Client handles
User interface programs and application programs
Open Database Connectivity (ODBC)
  Provides application programming interface (API)
Allows client-side programs to call the DBMS
Both client and server machines must have the necessary software installed
  Three Tier & N-Tier
Application server or Web server
Adds intermediate layer between client and the database server: Runs application programs and stores business rules

18. Two Tier, Three Tier and N-Tier
Divides the layers between the user and the stored data further into finer components

19. Understanding and using the system log for DB admin tasks
DBMS e.g. MySQL Server has several logs that can help you find out what activity is taking place.
By default, no logs are enabled (except the error log on Windows).
By default, the server writes files for all enabled logs in the data directory.
You can force the server to close and reopen the log files (or in some cases switch to a new log file) by flushing the logs
Using a FLUSH LOGS statement
The binary log is flushed when its size reaches the value of the max_binlog_size system variable.
You can enable or disable logging, or change the log file name.

20. Understanding and using the system log in database admin cont..
Log Type
Information Written to Log
Error log
Problems encountered starting, running, or stopping DBMS
General query log
Established client connections and statements received from clients
Binary log
Statements that change data (also used for replication)
Relay log
Data changes received from a replication master server
Slow query log
Queries that took more than the established thresh hold (long query time) to execute
DBMS e.g. MySQL Server has several logs that can help

21. Database Tuning
What is database tuning, and how can it be achieved in database administration?

22. Database backup and recovery
If you're storing anything in databases that you do not want to lose, it is very important to make regular backups of your data to protect it from loss
There are two easy ways to backup and restore the data in MySQL database.
Back up from the Command Line (using mysqldump)
Back up with Compress

23. Back up From the Command Line (using mysqldump)
You can backup MySQL data using the mysqldump command.
This command connects to the MySQL server and creates an SQL dump file.
The dump file contains the SQL statements necessary to re-create the database. The syntax is :
mysqldump --opt -u [uname] -p[pass] [dbname] > [backupfile.sql]
[uname] Your database username
[pass] The password for your database (note there is no space between -p and the password)
[dbname] The name of your database
[backupfile.sql] The filename for your database backup
[--opt] The mysqldump option

24. B Back up from the Command Line (using mysqldump)
E.g. mysqldump -u root -p Tutorials > tut_backup.sql
Backs up database named 'Tutorials' with the username 'root' and with no password to a file tut_backup.sql
You can also choose to specify certain tables of the database you want to backup by separating each table name with space.
mysqldump -u root -p Tutorials php_tutorials asp_tutorials > tut_backup.sql
You can back up more than one database at once using the --database option followed by the list of databases you would like to backup separated by space.
mysqldump -u root -p --databases Tutorials Articles Comments > content_backup.sql

25. Back up From the Command Line (using mysqldump)
To back up all the databases in the server at once you use the --all-databases option.
mysqldump -u root -p --all-databases > alldb_backup.sql
The mysqldump command has also some other useful options:
--add-drop-table: Tells MySQL to add a DROP TABLE statement before each CREATE TABLE in the dump.
--no-data: Dumps only the database structure, not the contents.
--add-locks: Adds the LOCK TABLES statement you can see in the dump file.

26. Backing up MySQL Database with Compress
If your mysql database is very big, you might want to compress the output of mysqldump.
pipe the output to gzip to get the output as gzip file.
mysqldump -u [uname] -p[pass] [dbname] | gzip -9 > [backupfile.sql.gz]
To extract the .gz file, use the command below:
gunzip [backupfile.sql.gz]

27. Restoring MySQL Database
To re-create the Tutorials database follow two steps:
Create an appropriately named database on the target machine
Load the file using the mysql command:
mysql -u [uname] -p[pass] [db_to_restore] < [backupfile.sql] e.g.
mysql -u root -p Tutorials < tut_backup.sql
To restore compressed backup files, do the following:
gunzip < [backupfile.sql.gz] | mysql -u [uname] -p[pass] [dbname]
To restore a database that already exists, you'll need to use mysql import command as follows: mysqlimport -u [uname] -p[pass] [dbname] [backupfile.sql]

28. Backing Up and Restoring using PHPMyAdmin
To backup MySQL database using PHPMyAdmin, just follow a couple of steps using phpMyAdmin’s menu options:
Open phpMyAdmin.
Select your database by clicking the database name in the list on the left of the screen.
Click the Export link. This should bring up a new screen that says View dump of database (or something similar).
In the Export area, click the Select All link to choose all of the tables in your database.
In the SQL options area, click the right options.
Click on the Save as file option and the corresponding compression option and then click the 'Go' button. A dialog box should appear prompting you to save the file locally.

29. Restoring your database using phpMyAdmin
Open phpMyAdmin.
Create an appropriately named database and select it by clicking the database name in the list on the left of the screen.
If you would like to rewrite the backup over an existing database then click on the database name, select all the check boxes next to the table names and select Drop to delete all existing tables in the database.
Click the SQL link. This should bring up a new screen where you can either type in SQL commands, or upload your SQL file.
Use the browse button to find the database file.
Click Go button. This will upload the backup, execute the SQL commands and re-create your database.

30. Securing your Databases
General factors that affect security.
choosing good passwords, not granting unnecessary privileges to users, ensuring application security by preventing SQL injections and data corruption, etc.
Security of the installation itself.
The data files, log files, and the all the application files of your installation should be protected to ensure that they are not readable or writable by unauthorized parties e.g. not storing them in the default directory.
Access control and security within the database system itself,
Grant users only required access to the databases, views and stored programs in use within the database.
Network security of MySQL and system.
Ensure appropriate permissions for users, an up-to-date anti virus, firewalls, ensure other Network security measures
Adequate & appropriate backups & tested recovery solution. See

31. Using an example of an organisation of your choice, list and explain best practices for database management-feedback from group discussion.
Replication in different locations
Normalised tables
Vendor specification guidelines
Backup & recovery plan/schedule
Configure audit logs/moninotring usage
Protect sensitive data e.g. encryption of passwords & credit card information
Database documentation that provides a clear understanding of the DB
Secure default configurations
Applying software updates for the DBMS & other applications

32. DB & web server must be placed in different machines for better security & performance
Routine check of DB & log size
Appropriate management of user access privileges
Run frequently penetration & intrusion detection tests

33. Develop & execute good database management practices
After people, data is your most important asset: below are some best practices for good DB management
Left unattended, databases will turn into piles of mush.
develop data entry policies and procedures, and train everyone who enters data.
Have some one in charge of training, user support, and data quality .
At a small organization, this might be a small part of someone's job. At a large organization, it might need to be a whole department.
Run backups religiously. Do test them periodically to make sure you can recover data.
Keep a copy of your data off-site e.g.
online backup service, a vendor that provides offsite storage and retrieval, or even by sending a backup home with a staff member but be aware about risks like theft, loss, aunauthorised access, etc.

34. Develop & execute good database management practices
Do all you can to prevent staff from downloading sensitive data (S.S numbers or credit card data) to laptops or memory sticks.
Use encryption on laptops and memory sticks.
Tools like Identity Finder, Proventsure, SENF, and Spider will scan your computers for sensitive data.
Require strong passwords. Do not share passwords. Change passwords regularly.
Monitor your data entry.
Run reports that look for common errors.
Identify staff members who repeatedly make errors and provide additional training.
If the errors continue, take away their data entry permissions.

35. Develop & execute good database management practices
Run your database on a need-to-know basis.
Give staff and volunteers access to only the data they need to see or change to do their jobs -- but make sure that they do have access to the data they need.
Make sure your database has enough security options.
provide read-only access where rights are not necessary e.g. names and addresses but not gifts.
provide update access to only certain portions of your data, like updating addresses but not entering gifts.
restrict access to sensitive functions like posting a gift batch
restrict the ability to run mass updates or delete records.
See more at:
See also PDF about best practices for database management

36. Individual Assignment
Using an example and a case study of either a bank, hospital or a university,
State and explain 5 best practices for:
Effective web design
Effective web administration
Effective database administration (20 marks)
Develop a web based application using the practices given in (a) (20marks)