Keys in DBMS  Keys in DBMS – CODD Rule: Before discussing keys in DBMS, you must learn the CODD Rule. CODD Rule says that – No two tuples of the table should be the same, means one tuple should differentiate from other tuple using same attribute set. (How we can get this?? — By Key…

 Relationship Constraints in DBMS – There are three Types of Relationship Constraints- Structural Constraints  Participation Constraints Cardinality Ratio Overlap Constraints Covering Constraints Structural Constraints are applicable for binary relationships and Overlap and Covering Constraints are applicable for EERD(Extended ER Diagrams). Participation (or) Optionality Constraints- Participation concerns with the involvement of entities in a relationship. It…

Types of Operating System – The post describes various Types of Operating System and the functions of operating system.  There are five types of operation system (OS) which are described as below : Batch Operating System Multi-programming Operating System Multitasking Operating System Multiprocessor Operating System Real Time Operation System Hard Real Time Soft Real Time…

ER MODEL (Entity Relationship Model) – Part-1 Before define ER Model, there are some terms which is require to understand ER model properly. In short, ER Model is a diagrammatic representation of entire Database tables. It represents a High Level Database Design. For Designing the Softwares : This phase is done in softwares by UML (Unified Modelling…

Operating System and their Goals, System Calls Operating System – Interface between user & computer. It is also called as a resource allocator. Because it is used for allocating the resources. Control program does not manage the system programs. System Calls – It is the request made by user application to operating system in order…

Questions on Super keys – Question 1 : Relational schema R with n attribute A1, A2,…,An. How many super keys are possible with a) only candidate keys A1 b) only Candidate Keys A1, A2 c) only Candidate keys (A1A2), (A3A4) d) only candidate keys (A1A2), (A2,A3) e) only candidate keys A1,A2,A3 ∩∪⇒ Solution : a) only…

1. Introduction & background 2. Process management • Process concept • Synchronization • Concurrent programming • Deadlocks • Threads 3. Memory management • RAM chip implementation • Address binding • Loading & linking • Techniques  Paging  Multi level paging  Inverted paging  Segmentation  Segmented paging 4. File & device management 5….

Advantages and Disadvantage of DBMS Advantages  of DBMS – Minimal Redundancy Inconsistency can be avoided Sharing of Data Standards can be enforced Search Capability Integrity Privacy and Security The interface with the Past The interface with the future Physical Data Independent Logical Data Independence Tunability Data Migration Simplicity Powerful User Languages Conflicting requirements can be…