Posts

Memory management in Operating System.

Image
  What is Memory management in Operating System? Memory management is a function of the OS. It helps us with: managing the system memory (primary memory) handling the movement of processes between main memory and disk during execution. keeping track of every memory location, whether allocated or free checking the amount of memory to be allocated to a process. deciding which process will get memory and at what time tracking when some memory is free or unallocated and updating its status OS Memory Management Techniques Following are the important memory management techniques: 1. Single Contiguous Allocation This is the easiest memory management technique where all types of computer memories except the one reserved for the OS are available for one application. 2. Partitioned Allocation In this allocation, the primary memory is divided into various memory partitions where each partition stores the information for a specific job. A job is given a partition when it starts executing and t...
3 comments
Read more

Data warehouse modelling with Snowflake Schema

Image
  ABSTRACT :  Snowflake is a data warehouse  schema design where dimension tables are normalized on top of a star schema design. Snowflake schema is generally not recommended due to its performance overhead in joining the normalized dimensions tables. However, the snowflake schema can be extended in a way to improve performance for business analysis activities in business analysis, two environments are complementary and work together to provide effective business analytics. Firstly, the data warehouse environment transforms operational data into information. Secondly, the analytical environment delivers information to end users for further data analysis and decision making. The snowflake schema bridges a gap between two environments. This schema facilitates the mapping of wide dimension structures with many dimensions attributes to analytical processing hierarchies. The snowflake schema makes navigation along hierarchies easier and support flexible analysis such as dril...
Post a Comment
Read more

Timed Automata and it's Applications

Image
Timed Automation :   In automata theory, a timed automaton is a finite automation extended with a finite set of real-valued clocks. During a run of a timed automaton, clock values increase all with the same speed. Along the transitions of the automaton, clock values can be compared to integers. These comparisons form guards that may enable or disable transitions and by doing so constrain the possible behaviours of the automaton. Further, clocks can be reset. Timed automata are a sub-class of a type hybrid automata. Timed automata can be used to model and analyse the timing behaviour of computer systems, e.g., real-time systems or networks. Methods for checking both safety and liveness properties have been developed and intensively studied over the last 20 years. It has been shown that the state reachability problem for timed automata is decidable, which makes this an interesting sub-class of hybrid automata. Extensions have been extensively studied, am...
21 comments
Read more