What is Hierarchical Data Model and Network data model

Image
1.Hierarchical Data Model:- A  Hierarchical Data Model request the data in tree like structure in which there is a single parent for each record. To maintain order there is a sort fields which. keep sibling in (child node) into a recorded manner.  This type of models are designed basically foe the early main frame database management system like the information management system This model allow one to one and one to many relationship between various type of data . The hierarchical structure is used as the from a physically order of record on storage  .Advantage of hierarchical model  A user can retrive data very quickly due to the presence of explicit links between the structure .Disadvantage   of hierarchical model     This type of database connect support complex relationship. When a user need to store the record in child to table that is currently to the unrelated to any record in a parent table than it gets difficult to record the user d...
Post a Comment

What is Thread Priority,Thread Exception and Thread Synchoranization

Thread Priority

In a multithreading environment thread Scheduler’s assign processor to a thread based on priority of thread standard value of priority for is a thread is an range of one to ten whenever we create a thread in java it always have some priority assign to it priority can either given by java virtual machine while creating a thread or it can be given by the program explicitly 



.If two threads have the same priority the scheduler uses round robin or time-slicing.
.Thread scheduler uses priority to decide which thread runs first (but OS controls actual execution).

Range of Thread Priority

.Java defines thread priorities asintegervaluesbetween5 and15      

.Thread MIN PRIORITY=5(Lowest priority)                                  

.Thread NORM PRIORITY=10(Default priority) 

.Thread MAX PRIORITY=20(Highest priority)

.Thread Exception  
In a multithreading usually the methods which halts the executions of the thread such as sleep, wait are written in try block. If any occurs to exception occurs it would be catch by catch block which create to the objects of class interrupted exception a parameter. 

.Key Points:-Thread exceptions only kill the affected thread, not the whole by the program. Always use try-catch in run() to safely handle exceptions. Use Uncaught Exception Handler for global exception handling in threads.

.Thread Synchronization
As we know multithreading number of thread are running resource simultaneously the thread may share same resource database, images, method. Just consider a thread is accessing a resource and means by while the to another thread try to access.

The same resource then same Irrelevant out put may generate to the provide to avoid this java, Synchronization the thread is accessing is the from specification resource for call other thread then we can use all on the  clock that resource for call other thread unless for all the first thread, leaves it access.

.Object:-The object class is the most top class and parent of all the classes in by java default. The widely used method of object class.

.Method1:-String (to string) this method returns the string resources representations of this object

.Method2:-(Void finalize) throws throwable this method is naught by the garbage collector before object is been garbage collected

    

Comments

Post a Comment

Popular posts from this blog

What is Computer engineering, complete information

Image
                                                                           Computer Engineering Computer Engineering is an engineering branch that is a combination of Computer Science and Electronics Engineering. Digital logic in design computer organization and architecture microprocessor in the system and interfacing computer networks and operating system. In this you learn the design, development and maintenance of both hardware (physical parts of the computer) and software (programs, applications, operating systems). 1.Scope of Computer Engineering                                                         . Computer Engineering students are taught these things:...
Read more

What is Constants, Variables, and Data Types

Image
                                          Constants   Constants in java refer to fixed values do not change during the execution of a program , Java support several types  of constants as illustrated. .Integer  Constants      An integer constant refer to a sequence of digits , There are three types integers .namely decimal imager octal integers and hexadecimals integers . Decimal integers consist of a set of thing preceded by an optional minus sign Valid of decimals integer constant  .Variables  A variable is an identifier that denotes a storage location seed to store a data value unlike constant that remain unchanged during the execution of a program , a variable may take different values at different times during the execution of the program ,we had used several variable for instance , we used variables length and breath to store the values o...
Read more

What is Diploma Engineering and How to Diploma engineering free course

Image
What is diploma in engineering is  a 3 year  course .All India  It is designed to students with practical skills and knowledge in a engineering.  After completing the diploma, students further education through into a bachelor's degree program or enter the diploma in engineering course   1.School Level (Class 10 )   .Focus on Math Science Physics and Chemistry - MSPC   . After class 10, you will have to take science stream. 2 .11th-12th Science Stream (MSPC Group)    .Physics, Chemistry, Mathematics (PCM) are compulsory subjects.    .You should prepare for entrance exams like JEE, MAHT-SET, VIT, BITSAT.   .You have to clear these exams after class 12. 3.Duration: 4 years   .Popular branches:   . Diploma in computer Science (CSE)   .  Diploma in m echanical   . Diploma in  civil   . Diploma in  electrical   . Diploma in  Electronics & Communication   . Diploma in...
Read more