Object Oriented Programming with C++

Comments

Post a Comment

Popular posts from this blog

UNIT - V Introduction to Transaction Processing Concepts and Theory

Image
  UNIT - V Introduction to Transaction Processing Concepts and Theory Topics Covered: Ø   Introduction Ø   Introduction to Transaction processing     Single user versus Multiuser systems     Transactions, Database Items, Read and Write Operations and DBMS Buffers.     Why concurrency control is needed     Why Recovery is needed Ø   Transactions and System concepts     Transaction states and Additional operations     System log     Ø   Desirable properties of transactions Ø      Characterizing Schedules based on Serializability. Introduction:                      One of the main advantages of storing data in a database is to allow sharing of it among multiple users. Several users access the database or perform operations at the same time. What if a user tries to access a d...
Read more

Introduction to mapping from ER model to Relational model

Image
  To understand Mapping (conversion) from Entity Relationship Model to Relational Model, you should have a knowledge (an idea) about:  ·        ER model  concepts ·        Relation model  concepts in Database design, mapping or Conversion of an E-R diagram into a relational model is very much required because E-R diagrams represent the conceptual level of the database design while the relational model represents the logical level of the Database design. The relational models can be easily implemented using RDBMS softwares like Oracle, MySQL, etc. The following steps shows, how mapping ER diagram to relational model: Step 1: Mapping  the regular/strong entities Step 2: Mapping   the  weak entities Step 3: Mapping 1:1 Relationships Step 4: Mapping 1:N Relationships Step 5: Mapping N:N Relationships Step 6: Mapping Multi-valued attribute and Composite attributes Exammple:...
Read more