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Template Metaprogramming is the idea used in this code.

Let's have a look at how this works. Non-data types can ALSO be used as parameters in C++ templates. The term "non-datatype" refers to a value rather than a datatype. In the preceding code, for example, N is passed as a value rather than a datatype. For each parameter, a new instance of a generic class is constructed, and these classes are created at compile time.

Explanation:

N is passed as a value rather than a data type in the above program. For each parameter, a new instance of a generic class is constructed, and these classes are created at compile time. When the compiler encounters the line “PrintZeroToN<>::print()” with N = 100, it produces an instance PrintZeroToN<100>. Another FUNCTION PrintZeroToN<99>::print() is called in function PrintZeroToN<100>::print(), resulting in the creation of an instance PrintZeroToN<99>. All instances from PrintZeroToN<100> to PrintZeroToN<1> are created in the same way. The function PrintZeroToN<0>::print() already exists and prints 0. The PrintZeroToN<1> function prints 1 and so on. As a result, all numbers from 0 to N are printed on the screen.

The sum of two bits can be found by executing an XOR (^) operation on the two bits. A carry bit can be obtained by performing AND (&) on the two bits.

The logic SHOWN below is a simple Half Adder that may be USED to add two single bits. This logic can be extended to integers. If there are no set bits at the same position(s) in a and b, bitwise XOR (^) of a and b yields the sum of a and b. Bitwise AND (&) is used to include COMMON set bits as well. All carry bits are obtained by bitwise AND of a and b. To acquire the needed result, we compute (a & b) << 1 and add it to a ^ b.

Monkey PATCHES are dynamic (or run-time) alterations of a class or module in Python. We can TRULY CHANGE the behavior of code at runtime in Python.

Example:

In the code below, we use the above module (m) to change the behavior of func() at runtime by assigning a new value.

Output:

Explanation: 

We have assigned the monkey_func to the address of “func” of class A. Thus, when we call the “func” function of “ob”, the monkey function is called.

Because static methods are resolved at compile time, one cannot override them in Java. Because objects are only available at runtime, overriding REQUIRES a virtual METHOD that is resolved at runtime. In Java, a static method can be overloaded. Overloading has nothing to do with runtime, but each method's signature must be distinct. To alter the method signature in Java, EITHER the number of parameters, the type of ARGUMENTS, or the sequence of arguments must be changed.

In Java, you can't override a private method because the subclass doesn't inherit the private method, which is required for overriding. In fact, no one outside the CLASS can see a private method, and a call to it is handled at compile time using Type information rather than at runtime using the actual object.

The Garbage Collector (GC) must CALL the FINALIZE method on an object when it becomes garbage COLLECTION eligible. Because the finalize method can only be used once, the GC marks the object as finalized and sets it aside until the next cycle.

You can technically "resurrect" an object in the finalize method by assigning it to a static field, for example. The object would revive and become ineligible for garbage collection, preventing the GC from collecting it in the next cycle.

The object, on the other hand, would be marked as finalized, thus the finalize method would not be invoked when it became eligible again. In essence, you can only use this "resurrection" method only once.

Example:

Output:

Explanation:

The finalize method adds the items to the collection once and then resurrects them. They have been marked as finalized and will not be queued again when they are collected a second time.

The stack is a SECTION of memory that stores information about nested method (RECURSIVE)  calls all the WAY down to the present program location. It also holds all local variables and heap references defined in the currently running procedures. This structure enables the runtime to return from the method knowing the address from which it was invoked, as well as to remove all local variables when the procedure has been exited. EVERY thread has a stack of its own.

The heap is a big chunk of memory used for dynamic allocation. When you use the new keyword to create an object, it is allocated on the heap. The reference to this object, on the other hand, is stored on the stack.

BufferedWriter is a TEMPORARY data storage source. It's used to make a buffered character output stream with the default output buffer size.

To flush CHARACTERS from the buffered writer stream to a file, the flush() function of the BufferedWriter class in Java is employed. It ensures that all data items, including the last character, are WRITTEN to the file.

The close() function of the Java BufferedWriter class flushes the characters from the buffer stream and then closes it. Calling methods like write() and append() after the stream has been CLOSED will generate an ERROR.

A bidirectional communication channel is provided by a pair of virtual CHARACTER devices known as a pseudo TTY (or "PTY"). The master is at one end of the channel, while the slave is at the other. The pseudo-terminal's slave end provides an INTERFACE that is IDENTICAL to that of a conventional terminal. A process that expects to be connected to a terminal can open the slave end of a pseudo-terminal, which will subsequently be controlled by a program that has opened the master end. Anything written on the master end is supplied to the slave end's process as if it were any input entered on a terminal. Anything written to the slave end of the pseudo-terminal, on the other hand, can be read by the process linked to the master end. Network login services, terminal emulators, and other such applications EMPLOY pseudo-terminals.

The Hamming code is a set of error-correction codes that can be used to detect and fix errors that can arise when DATA is transferred or stored from one source to ANOTHER. Redundant bits are extra BINARY bits that are created and ADDED to the data TRANSFER's information-carrying bits to ensure that no bits are lost during the data transfer. A parity bit is a bit that is appended to binary data to verify that the total number of 1s is even or odd. Error detection is done with parity bits. The Hamming Code is essentially the use of additional parity bits to allow for error detection.

RATHER than communicating in native "languages", all Telnet clients and servers agree to deliver data and commands that conform to a fictional "virtual" terminal TYPE known as the NETWORK Virtual Terminal (NVT). The NVT specifies a set of standards for formatting and sending data, including character set, line termination, and how INFORMATION about the Telnet session is provided.

Every Telnet client on a terminal can COMMUNICATE in both its native language and NVT. When a user enters information on his or her local terminal, it is translated to NVT and sent over the network in that format. When the Telnet server receives this information, it converts it from NVT to the format required by the remote host. In reverse, the same procedure is followed for transmissions from the server to the client.

The Exterior Gateway Protocol (EGP) is a protocol that allows INTERNET gateways from the same or separate autonomous systems to SHARE network reach-ability information.

EGP serves THREE primary purposes:

• CREATE a SET of neighbors.
• Keep a check on the neighbors (to see if they are still alive and reachable).
• Notify the neighbors about the networks that are accessible from their autonomous systems.

A bridge router, SOMETIMES known as a brouter, is a network DEVICE that can FUNCTION as both a bridge and a router. The brouter forwards all other packets LIKE a bridge and only routes packets for known protocols.

For routable protocols, brouters function at the network layer, while for non-routable protocols, they operate at the data link layer. Brouters operate as routers for routable protocols and bridges for non-routable protocols, handling both routable and non-routable characteristics. Brouters are connecting devices in networking SYSTEMS that serve as both a network bridge and a router in the internetwork.

At any given time, the resident SET is the part of the processed image that is actually in the real memory. It's broken down into SUBSETS, one of which is the WORKING set. The working set is the SUBSET of the resident set required for EXECUTION.

TRANSLATION TLB (Transaction Look-aside Buffer) is a particular cache that keeps track of RECENTLY used transactions. The TLB includes the most recently used page table entries. The CPU analyses the TLB when given a VIRTUAL ADDRESS. The frame number is retrieved and the real address is created if a page table entry (TLB hit) is present. If a page table entry is missing from the TLB (TLB miss), the page number is used as an INDEX while processing the page table. The TLB first checks if the page is already in main memory; if it isn't, a page fault is generated, and the TLB is then modified to incorporate the new page entry.

A trapdoor is a software or hardware mechanism that can be USED to bypass system controls. In general, it's malicious software that allows an attacker on the other side of the Internet to gain unauthorized access to a computer system or network by accepting remote commands. Trap DOOR software monitors a specific Transmission Control PROTOCOL (TCP) or User Datagram Protocol (UDP) PORT for orders.

The typical elements of a processed image are:

• USER data: This element of user space INCLUDES program data, user stack area, and programs that can be modified.
• User program: The set of instructions that are to be executed.
• System Stack: Each process is associated with one or more LIFO (Last In First Out) stacks. Parameters and calling addresses for procedure and system CALLS are stored here.
• Process control Block (PCB): Information required by the OPERATING system to control OPERATIONS.

Plumbing/ Piping refers to the technique of USING one program's output as an input to another. For instance, Instead of DELIVERING a folder or drive listing to the main screen, it can be piped and delivered to a file, or sent to the printer to print a hard copy.

A pipe is a type of redirection (the transfer of standard output to another location) USED in Linux and other Unix-like OPERATING systems to transport the output of one command/program/process to another for additional processing. The Unix/Linux systems allow a command's stdout to be CONNECTED to another command's stdin. The pipe character ‘|' can be used to do this.

Preemptive multitasking permits computer programs to share operating systems (OS) and UNDERLYING hardware resources. It distributes the OVERALL operating and computing time amongst processes, and it uses ESTABLISHED criteria to switch resources between processes. Time-shared multitasking is ANOTHER name for preemptive multitasking.

The operating system never initiates context switching from one process to another in cooperative multitasking. Only when the processes voluntarily cede control on a routine basis, or when they are inactive or logically blocked, does a context switch occur, allowing MANY applications to run at the same time. In addition, in this multitasking, all processes work together to make the scheduling strategy work.

CACHING is a technique for saving numerous COPIES of the most frequently used data in a temporary storage area (or cache) so that they can be accessed more quickly. It keeps data in a temporary format for software applications, servers, and web browsers, so users don't have to download information every TIME they VISIT a website or use an application.

Cached data works by saving data in a device's memory for later access. The data is kept in the memory of a computer, directly below the central processing unit (CPU). The primary cache level is incorporated into a device's microprocessor CHIP, followed by two more secondary cache levels that feed the primary level. This information is kept until the content's time to live (TTL), which specifies how long it should be cached, expires or the device's disc or hard drive cache fills up.

Data is usually cached in one of two ways: browser or memory caching (data stored locally on the computer) or Content Delivery Networks (data stored in geographically distributed locations).

An abstract layer on top of a more concrete file system is a virtual file system (VFS) or virtual filesystem switch. 

• The purpose of a VFS is to make it possible for client applications to access various types of concrete file systems in a consistent MANNER. For example, a VFS can be used to seamlessly access LOCAL and network storage devices WITHOUT the client device recognizing the difference.
• It can be used to bridge the gap between Windows, traditional Mac OS/macOS, and Unix filesystems, allowing applications to access files on those sorts of local file systems without needing to KNOW what type of file system they're dealing with.
• A VFS defines the kernel's interface with a certain file system. As a result, adding SUPPORT for new file system types to the kernel is simple.

The root partition is the place where the operating system kernel is LOCATED. Other potentially crucial system files that are mounted during boot TIME are contained in it as WELL.

In dynamic LOADING, a routine is not loaded until it is CALLED. This strategy is very effective when dealing with VAST quantities of code, such as error routines, that occur infrequently. All routines are saved in a relocatable load format on the disk. The main program is executed after it has been loaded into MEMORY. When a routine requires to call another routine, the calling routine checks to verify if the other routine is loaded first. If this is not the CASE, the relocatable linking loader is used to load the requested routine into memory and update the program's address tables. The newly loaded routine is then given control. In this way, dynamic loading helps in better memory space utilization.

One of the FACTORS is that it is DEPENDENT on how frequently a deadlock is likely to OCCUR when this algorithm is IMPLEMENTED. The other is the number of processes that will be affected by deadlock if this algorithm is used.

SJF (Shortest Job First) is a scheduling policy that prioritizes the waiting PROCESS with the shortest EXECUTION time. Shortest Job Next (SJN) or Shortest Process Next are other names for it (SPN). It is a scheduling algorithm that is not preemptive (that is, one process cannot SNATCH the resources assigned to a currently running process).

The preemptive variant of SJF scheduling is the Shortest Remaining Time First (SRTF). The procedure, next in the queue, with the least amount of time till completion is chosen to be executed in this scheduling technique. Processes that arrive at the same time transform SRTF to SJF.

Similarities:

• Both SJF and SRTF are ESSENTIALLY difficult to implement since the processes' burst time cannot be predicted.
• Both SJF and SRTF have the potential to cause process starvation since long processes can be delayed forever if short processes are constantly added.
• Once all of the processes are in the ready queue, both SJF and SRTF are regarded the same. This is because no preemption is performed after the processes are added to the ready queue.

 In SQL, a view is a single table that contains data from other tables. As a result, a view features rows and columns that are IDENTICAL to those of a real table, as well as fields from one or more tables.

In ORDER to create a view:

For updating a view:

For dropping a view:

In the above queries, Column1, Column2, .. ColumnN denotes the name of the columns to be ADDED or updated. View_Name denotes the name of the view created and Table_name denotes the name of the current table.

Index hunting is the METHOD of boosting a collection of indexes. This is done because indexes improve query performance as well as query processing time.

It aids in query performance IMPROVEMENT in the following ways:

• Using the query optimizer, the optimal queries are suggested.
• To CHECK the effect, parameters such as index, query DISTRIBUTION, and performance are used.
• Databases are OPTIMIZED into a small group of problem queries.

The fill FACTOR is the percentage of space on each leaf-level page that will be filled with data. The smallest unit in SQL SERVER is a page, which is made up of 8K pages. Depending on the size of the row, each page can store one or more rows. The Fill Factor's default value is 100, which is the same as the value 0. The SQL Server will fill the leaf-level pages of an index with the highest NUMBER of rows it can fit if the Fill Factor is set to 100 or 0. When the fill factor is 100, the page will have no or very little vacant space.

• PROACTIVE Updates: These CHANGES are MADE to the database before it is put into use in the real-world ENVIRONMENT.
• Retroactive Updates: These updates are applied to a database after it has been operational in the real-world environment.
• Simultaneous Updates: These updates are applied to the database at the same moment as they become FUNCTIONAL in the real-world environment.

We may acquire the address of any VARIABLE by USING the “address of operator” (&) operator, which yields the variable's address.

#include <iostream>using namespace STD;int MAIN(){ char str[100]; int len = 0; cout << "Enter a STRING: "; cin >> str; while(str[len] != '\0') { len++; } cout << "Length of the GIVEN string is: " << len; cout << ENDL; return 0;}