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The entire operating system works in the kernel space in the monolithic system. This increases the size of the kernel as well as the operating system. This is different than the microkernel system where the minimum software that is required to correctly implement an operating system is kept in the kernel.A diagram that demonstrates the architecture of a monolithic system is as follows −The kernel provides various services such as memory management, file management, process scheduling etc. using function calls. This makes the execution of the operating system quite fast as the services are implemented under the same address space.Differences ... Read More
We can find all the triggers associated with a particular table with the help of the following query −mysql> Select * from INFORMATION_SCHEMA.TRIGGERS WHERE TRIGGER_SCHEMA = 'query'AND EVENT_OBJECT_TABLE = 'Student_info'\G *************************** 1. row *************************** TRIGGER_CATALOG: def TRIGGER_SCHEMA: query TRIGGER_NAME: studentinfo_after_delete EVENT_MANIPULATION: DELETE EVENT_OBJECT_CATALOG: def EVENT_OBJECT_SCHEMA: query EVENT_OBJECT_TABLE: student_info ACTION_ORDER: 1 ACTION_CONDITION: NULL ... Read More
System programs provide an environment where programs can be developed and executed. In the simplest sense, system programs also provide a bridge between the user interface and system calls. In reality, they are much more complex. For example: A compiler is a complex system program.The user view of the system is actually defined by system programs and not system calls because that is what they interact with and system programs are closer to the user interface.An image that describes system programs in the operating system hierarchy is as follows −In the above image, system programs as well as application programs ... Read More
The Main method is the entry point for all C# programs. It states what the class does when executed.The valid variant of Main() is −static void Main(string[] argsHere,static − the object is not needed to access static membersvoid − return type of the methodMain − entry point for any C# program. Program execution begins here.string[] args − for command line arguments in C#.ExampleHere is an example −using System; namespace Program { public class Demo { public static void Main(string[] args) { Console.WriteLine("Welcome!"); Console.ReadKey(); } } }
Main ThreadThe first thread to be executed in a process is called the main thread. When a C# program starts execution, the main thread is automatically created.Child ThreadThe threads created using the Thread class are called the child threads of the main thread.Here is an example showing how to create a main and child thread −Example Live Demousing System; using System.Threading; namespace Demo { class Program { static void Main(string[] args) { Thread th = Thread.CurrentThread; th.Name = "MainThread"; Console.WriteLine("This is {0}", th.Name); Console.ReadKey(); } } }OutputThis is MainThread
To initialize a dictionary to an empty dictionary, use the Clear() method. It clears the dictionary and forms it as empty.dict.Clear();After that, use the Dictionary count property to check whether the list is empty or not −if (dict.Count == 0) { Console.WriteLine("Dictionary is empty!"); }Let us see the complete code −Example Live Demousing System; using System.Collections.Generic; using System.Linq; namespace Demo { public class Program { public static void Main(string[] args) { var dict = new Dictionary < string, string > (); dict.Clear(); if (dict.Count == 0) { Console.WriteLine("Dictionary is empty!"); } } } }OutputDictionary is empty!
Sets in C# is a HashSet. HashSet in C# eliminates duplicate strings or elements in an array. In C#, it is an optimized set collectionTo declare HashSet −var h = new HashSet(arr1);Above, we have set the already declared array arr1 in the HashSet.Now set it on the array to remove the duplicate words −string[] arr2 = h.ToArray();Let us see an example to remove duplicate strings using C# HashSet.Here, we have duplicate elements −Exampleusing System; using System.Collections.Generic; using System.Linq; class Program { static void Main() { string[] arr1 = {"Table", "Chair", "Pen", "Clip", "Table"}; ... Read More
Actually ‘FOR EACH ROW’ means for each of the matched rows that get either updated or deleted. In other words, we can say that trigger is not applied to each row, it just says to execute the trigger body for each affected table row. We can illustrate this by the following example −ExampleIn this example, we are creating two tables, Sample and Sample_rowaffected, as follows −mysql> Create table Sample(id int, value varchar(20)); Query OK, 0 rows affected (0.47 sec) mysql> Insert into Sample(id, value) values(100, 'same'), (101, 'Different'), (500, 'excellent'), (501, 'temporary'); Query OK, 4 rows affected (0.04 sec) ... Read More
Actually, MySQL determines the end of the statement when it got termination semicolon. Suppose if we are writing a single statement in different lines then after writing the first line, MySQL changes promptly from ‘mysql>’ to ‘->’ which indicates that MySQL has not seen a complete statement yet and is waiting for the rest. When it got semicolon then MySQL executes the statement. It can be understood with the help of the following example −Examplemysql> Select Id, Name -> From -> Student_info -> ; +------+---------+ | Id | Name | +------+---------+ ... Read More
If there is ‘empty set’ in the result set of MySQL query then it means that MySQL is returning no rows and no error also in the query. It can be understood with the help of the following example −mysql> Select * from Student_info WHERE Name = 'ABCD'; Empty set (0.00 sec)We can see the empty set and execution time as output. It means that the query is correct but the MySQL table is not having the name ‘ABCD’.