normalization,ddl,dml,dcl
DESCRIPTION
Normalization,ddl,dml,dclTRANSCRIPT
Disclaimer: This presentation is prepared by trainees of baabtra as a part of mentoring program. This is not official document of baabtra –Mentoring PartnerBaabtra-Mentoring Partner is the mentoring division of baabte System Technologies Pvt . Ltd
Week Target Achieved
1 20 12
2 20 15
3
Typing Speed
Jobs Applied# Company Designation Applied Date Current Status
1
2
3
Normalization,ddl,dml,dcl
Name MOHAMMED NASEEF [email protected] naseef ppnaseefpp92in.linkedin.com/in/profilename9995614354
What is normalization
• Database normalization is the process of organizing the fields and tables of a relational database to minimize redundancy and dependency
• Normalization usually involves dividing large tables into smaller (and less redundant) tables and defining relationships between them.
• The objective is to isolate data so that additions, deletions, and modifications of a field can be made in just one table and then propagated through the rest of the database using the defined relationships.
• Two goals of normalization process: Eliminating Redundant Data Ensuring data dependencies
• Main objective: Isolate data Reduce the amount of database space Make database structure flexible Consistent throughout database
Normalization Stages
• 1NF• 2NF• 3NF• Boyce-Codd Normal Form (BCNF or 3.5NF)
First Normal Form (1NF)
• The values in each column of a table are atomic .
• Each table has a primary key.• There are no repeating groups.
Second Normal Form (2NF)
• Should be in 1NF.• Remove subsets of data that apply to multiple
rows of a table and place them in separate tables.
• Create relationships between tables.
Third Normal Form (3NF)
• should be 2NF.• Has no transitive functional dependencies.• Remove columns that are
not dependent upon the primary key.• To convert 2NF to 3NF, we again divide tables.
Boyce-Codd Normal Form(BCNF)
• Should be 3NF.• Every determinant must be a candidate key.• All tables can have only one primary key• Candidate Key:
Any attribute or a set of attributes together that has the eligibility to become a primary key.
What is ddl?
• DDL (Data definition language) defines your database structure. CREATE and ALTERare DDL statements as they affect the way your database structure is organized.
What is dml?
• DML (Data Manipulation Language) lets you do basic functionalities like INSERT,UPDATE, DELETE and MODIFY data in database
What is dcl?
• DCL (Data Control Language) controls you DML and DDL statements so that your datais protected and has consistency. COMITT and ROLLBACK are DCL control statements.DCL guarantees ACID fundamentals of a transaction.
If this presentation helped you, please visit our page facebook.com/baabtra and like it.
Thanks in advance.
www.baabtra.com | www.massbaab.com |www.baabte.com
Contact Us
Emarald Mall (Big Bazar Building)Mavoor Road, Kozhikode,Kerala, India.Ph: + 91 – 495 40 25 550
NC Complex, Near Bus StandMukkam, Kozhikode,Kerala, India.Ph: + 91 – 495 40 25 550
Start up VillageEranakulam,Kerala, India.
Email: [email protected]