Database Languages are the set of statements, that are used to define and manipulate a database. A Database language has Data Definition Language (DDL), which is used to construct a database & it has Data Manipulation Language (DML), which is used to access a database. DDL implements database schema at the physical, logical and external level. While, the DML provides the … [Read more...] about Database Languages
View of Data in DBMS
View of data in DBMS narrate how the data is visualized at each level of data abstraction? Data abstraction allow developers to keep complex data structures away from the users. The developers achieve this by hiding the complex data structures through levels of abstraction. There is one more feature that should be kept in mind i.e. the data independence. While changing the … [Read more...] about View of Data in DBMS
Entity Set
Entity Set is a collection or a group of 'entities' sharing exactly the 'same set of attributes'. All entities can be distinctly identified in an entity set. This is because all the entities have a different set of value for some set of attributes. We further classify the entity set into two basic categories Strong and Weak entity set. The collection of entity sets and their … [Read more...] about Entity Set
Register Organization
Register organization is the arrangement of the registers in the processor. The processor designers decide the organization of the registers in a processor. Different processors may have different register organization. Depending on the roles played by the registers they can be categorized into two types, user-visible register and control and status register. Before learning … [Read more...] about Register Organization
Cache Coherence
Cache Coherence assures the data consistency among the various memory blocks in the system, i.e. local cache memory of each processor and the common memory shared by the processors. It confirms that each copy of a data block among the caches of the processors has a consistent value. In this section, we will discuss the cache coherence problem and the protocol for resolving … [Read more...] about Cache Coherence
Direct Memory Access (DMA)
Direct Memory Access (DMA) transfers the block of data between the memory and peripheral devices of the system, without the participation of the processor. The unit that controls the activity of accessing memory directly is called a DMA controller. The processor relinquishes the system bus for a few clock cycles. So, the DMA controller can accomplish the task of data … [Read more...] about Direct Memory Access (DMA)
RISC Processor
RISC is an abbreviation of Reduced Instruction Set Computer. RISC processor has 'instruction sets' that are simple and have simple 'addressing modes'. A RISC style instruction engages "one word" in memory. Execution of the RISC instructions are faster and take one clock cycle per instruction. Although the forerunners of RISC computers were seen in 1960. But, due to the … [Read more...] about RISC Processor
Difference Between Hardwired and Microprogrammed Control Unit
The Hardwired and Microprogrammed control unit generates the control signals to fetch and execute instructions. The fundamental difference between hardwired and microprogrammed control unit is that hardwired is a circuitry approach whereas, the microprogram control unit is implemented by programming. The hardwired control unit is designed for the RISC style instruction set. … [Read more...] about Difference Between Hardwired and Microprogrammed Control Unit
CISC Processor
CISC is an abbreviation for Complex Instruction Set Computer. CISC processors were evolved in the 1970s before the evolution of RISC (Reduced Instruction Set Computers) processors. During this period the computer memory uses to be 'small' and 'very expensive'. CISC processors were helpful in simplifying the code and making it shorter in order to reduce the memory … [Read more...] about CISC Processor
Addressing Mode and its Types
Addressing modes specifies the way, the effective address of an operand is represented in the instruction. Some addressing mode efficiently allows referring to a large range of area like a linear array of addresses and list of addresses. Addressing mode describes a flexible and efficient way to define complex effective address. Generally, the programs are written in a … [Read more...] about Addressing Mode and its Types