Reference notes

DBMS Notes

DATA MODELS AND SCHEMAS

What is database? What is DBMS? What is a Database system? Advantages of DBMS? Disadvantage in File Processing System? Describe the three levels of data abstraction? Define the "integrity rules" What is extension and intension? What is System R? What are its two major subsystems? How is the data structure of System R different from the relational structure? What is Data Independence? What is a view? How it is related to data independence? What is Data Model? What is E-R model? What is Object Oriented model? What is an Entity? What is an Entity type? What is an Entity set? What is an Extension of entity type? What is Weak Entity set? What is an attribute? What is a Relation Schema and a Relation? What is degree of a Relation? What is Relationship? What is Relationship set? What is Relationship type? What is degree of Relationship type? What is DDL (Data Definition Language)? What is VDL (View Definition Language)? What is SDL (Storage Definition Language)? What is Data Storage - Definition Language? What is DML (Data Manipulation Language)? What is DML Compiler? What is Query evaluation engine? What is DDL Interpreter? What is Record-at-a-time? What is Set-at-a-time or Set-oriented? What is the basic difference between DBMS and RDBMS ?

RELATIONAL ALGEBRA AND RELATIONAL CALCULUS

What is super key ? Whats is candidate key ? What is weak entity set ? What is Primary key ? what is foreign keys ? what is Discriminator ? What are partial, alternate,, artificial, compound and natural key? What is trigger ? Authorization in SQL ? What is Roles ? Drop and Alter Command ? Aggregate Functions When is a functional dependency F said to be minimal? What is Multivalued dependency? What is Lossless join property? What is Relational Algebra? What is Relational Calculus? How does Tuple-oriented relational calculus differ from domain-oriented relational calculus What are the unary operations in Relational Algebra? Are the resulting relations of PRODUCT and JOIN operation the same?

NORMALIZATION

What is normalization? what is goal of normalization? ? tell me abt 1NF, 2NF, and 3NF ,4NF How to eliminate the values in an attribute having moe than one? what is Functional Dependency in Database Normalization what is Transitive Dependency in Database Normalization Boyce Boyce-Codd Codd Normal Form ? What is 5NF? What is 1 NF (Normal Form)? What is Fully Functional dependency? What is 2NF? What is 3NF? What is BCNF (Boyce-Codd Normal Form)? What is 4NF?

STORAGE, INDEXING AND QUERY PROCESSING

What is indexing and what are the different kinds of indexing? How many kinds of indices What is Dense Index ? what is Sparse Index ? Explain B+ Tree Index ? Explain B Tree Index ? What is hash function ? Explain Dyanmic Hashing ? Explain Bitmap Indices?

TRANSACTIONS

What is database transaction ? what is rollback ? What are savePoints ? what is commit ? What is atomic commit ? Two phase commit ? Three phase commit ? What is durability in DBMS? What do you mean by atomicity and aggregation? What are the different phases of transaction? What are ACID properties ?

SQL

Which is the subset of SQL commands used to manipulate Oracle Database structures, including tables? What operator performs pattern matching? What operator tests column for the absence of data? Which command executes the contents of a specified file? What is the parameter substitution symbol used with INSERT INTO command? Which command displays the SQL command in the SQL buffer, and then executes it? What are the wildcards used for pattern matching? State true or false. EXISTS, SOME, ANY are operators in SQL. State true or false. !=, <>, ^= all denote the same operation. What are the privileges that can be granted on a table by a user to others? What command is used to get back the privileges offered by the GRANT command? Which system tables contain information on privileges granted and privileges obtained? Which system table contains information on constraints on all the tables created? TRUNCATE TABLE EMP; What is the difference between TRUNCATE and DELETE commands? What command is used to create a table by copying the structure of another table? What will be the output of the following query? What does the following query do? Which date function is used to find the difference between two dates? Why does the following command give a compilation error? What is the advantage of specifying WITH GRANT OPTION in the GRANT command? What is the use of the DROP option in the ALTER TABLE command? What is the value of ?comm? and ?sal? after executing the following query if the initial value of ?sal? is 10000? What is the use of DESC in SQL? What is the use of CASCADE CONSTRAINTS? What is the output of the following query? What are stored-procedures? And what are the advantages of using them. How are exceptions handled in PL/SQL? Give some of the internal exceptions' name Does PL/SQL support Overloading? Explain.

OPERATING SYSTEMS NOTES

PROCESS AND THREADS

What is a process ? What are the various process states ? What are the typical elements of a process image? what is PCB ? what do you mean by context switch? what do you mean by Cooperating Processes ? Explain Producer Consumer Problem. Explain InterProcess Communications. Explain RPC ? Explain marshalling ? What are threads ? Differenciate between threads and Processes ? What are various multithreading models ?

CPU SCHEDULING

Define response time, turnaround and throughput. define pre-emptive and non-preemptive schheduling. What are short-, long- and medium-term scheduling? What is dispatcher ? What are the different scheduling criterions. Explain various cpu scheduling algorithm ? What is busy waiting?

PROCESS SYNCHRONIZATION

Explain race conditions ? Explain critical section problem ? what is the solution to Critical-Section Problem ? Explain Bakery Algorithm ? what are semaphores ? Explain its types ? What is MUTEX ? What is Concurrency? Explain with example Deadlock and Starvation. What are your solution strategies for "Dining Philosophers Problem" ? Explain starvation ? Explain Monitor ? Explain Dining Philosphor's problem.

DEADLOCKS

Explain deadlock ? What is a Safe State and what is its use in deadlock avoidance?

MEMORY MANAGEMENT

Explain compile time, load time and execution time ? What do you mean by logical address and physical address space ? What is MMU ? Explain Dynamic loading ? Explain Dynamic Linking ? Explain overlays ? Explain swapping ? What do you mean by Hole from the perspective of Memory Management? Explain Dynamic Storage-Allocation Problem ? Explain Address Translation Scheme. Explain Fragmentation ? what is external fragmentation and internal fragmentation ?

VIRTUAL MEMORY

Explain virtual memory. Explain paging. Explain demand paging. Explain segmentation. Explain demand segmentation. what do you mean by page fault ? How does an OS handle a page fault situation ? Explain Page Replacement and various page replacement algorithms ? What do you mean by thrashing

DATA STRUCTURES NOTES

·    DECLARATIONS AND INITIALIZATIONS

·          What is the difference between char *a and char a[]? ·          How can I declare an array with only one element and still access elements  beyond the first element (in a valid fashion)? ·          What's the difference between using a typedef or a #define for a user-defined  type? ·          Is char a[3] = "abc"; legal? ·          What is the difference between enumeration variables and the preprocessor  #defines?

·    VARIABLES AND DATA TYPES

·          What is the difference between the declaration and the definition of a variable? ·          Do Global variables start out as zero? ·          Does C have boolean variable type? ·          Where may variables be defined in C? ·          To what does the term storage class refer? What are auto, static, extern,  volatile, const classes? ·          What does the typedef keyword do? ·          What is the difference between constants defined through #define and the  constant keyword? ·          What are Trigraph characters? ·          How are floating point numbers stored? Whats the IEEE format? ·          When should the register modifier be used? ·          When should a type cast be used?

·    EXPRESSIONS

·          Whats short-circuiting in C expressions? ·          Whats wrong with the expression a[i]=i++; ? Whats a sequence point? ·          Does the ?: (ternary operator) return a lvalue? How can I assign a value  to the output of the ternary operator? ·          Is 5[array] the same as array[5]? ·          What are #pragmas? ·          What is the difference between if(0 == x) and if(x == 0)? ·          Should we use goto or not? ·          Is ++i really faster than i = i + 1? ·          What do lvalue and rvalue mean? ·          What does the term cast refer to? Why is it used? ·          What is the difference between a statement and a block? ·          Can comments be nested in C? ·          What is type checking? ·          Why can't you nest structure definitions? ·          What is a forward reference? ·          What is the difference between the & and && operators and  the | and || operators? ·          Is C case sensitive (ie: does C differentiate between upper and lower  case letters)? ·          Can goto be used to jump across functions? ·          Whats wrong with #define myptr int *? ·          What purpose do #if, #else, #elif, #endif, #ifdef, #ifndef serve? ·          Can we use variables inside a switch statement? Can we use  floating point numbers? Can we use expressions? ·          What is more efficient? A switch() or an if() else()? ·          What is the difference between a deep copy and a shallow copy? ·          What is operator precedence?

·    ARRAYS AND POINTERS

·          How to write functions which accept two-dimensional arrays when the width  is not known before hand? ·          If a is an array, is a++ valid? ·          Is char a[3] = "abc"; legal? What does it mean? ·          How can we find out the length of an array dynamically in C? ·          What does *p++ do? Does it increment p or the value pointed by p? ·          What is a NULL pointer? How is it different from an unitialized pointer?  How is a NULL pointer defined? ·          What is a null pointer assignment error? ·          Does an array always get converted to a pointer? What is the  difference between arr and &arr? How does one declare a pointer  to an entire array? ·          Is the cast to malloc() required at all? ·          What does malloc() , calloc(), realloc(), free() do?  What are the common problems with malloc()? Is there a way to  find out how much memory a pointer was allocated? ·          What's the difference between const char *p, char * const p and const  char * const p? ·          What is a void pointer? Why can't we perform arithmetic on a void * pointer? ·          What do Segmentation fault, access violation, core dump and Bus error mean? ·          What is the difference between an array of pointers and a pointer to an array? ·          What is a memory leak? ·          What are brk() and sbrk() used for? How are they different from malloc()? ·          What is a dangling pointer? What are reference counters with  respect to pointers? ·          What do pointers contain? ·          Is *(*(p+i)+j) is equivalent to p[i][j]? Is num[i] == i[num] == *(num + i) == *(i + num)? ·          What operations are valid on pointers? When does one get  the Illegal use of pointer in function error? ·          What are near, far and huge pointers? ·          What is the difference between malloc() and calloc()? ·          Why is sizeof() an operator and not a function? ·          What is an opaque pointer? ·          What are the common causes of pointer bugs?

·    FUNCTIONS

·          How to declare a pointer to a function? ·          Does extern in a function declaration mean anything? ·          How can I return multiple values from a function? ·          Does C support function overloading? ·          What is the purpose of a function prototype? ·          What are inline functions? ·          How to declare an array of N pointers to functions   returning pointers to functions returning pointers to characters? ·          Can we declare a function that can return a pointer to a function of the same type? ·          How can I write a function that takes a variable number of arguments?  What are the limitations with this? What is vprintf()? ·          With respect to function parameter passing, what is the difference between  call-by-value and call-by-reference? Which method does C use? ·          If I have the name of a function in the form of a string, how can I invoke that function? ·          What does the error, invalid redeclaration of a function mean? ·          How can I pass the variable argument list passed to one function to another function. ·          How do I pass a variable number of function pointers to a  variable argument (va_arg) function? ·          Will C allow passing more or less arguments than required to a function. ·          Whats the difference between gets() and fgets()?  Whats the correct way to use fgets() when reading a file? ·          How can I have a variable field width with printf? ·          How can I specify a variable width in a scanf() format string? ·          How can I convert numbers to strings (the opposite of atoi)? ·          Why should one use strncpy() and not strcpy()?  What are the problems with strncpy()? ·          How does the function strtok() work? ·          Why do we get the floating point formats not linked error? ·          Why do some people put void cast before each call to printf()? ·          What is assert() and when would I use it? ·          What do memcpy(), memchr(), memcmp(), memset(), strdup(), strncat(),strcmp(),  strncmp(), strcpy(), strncpy(), strlen(), strchr(), strchr(),strpbrk(),  strspn(), strcspn(), strtok() do? ·          What does alloca() do? ·          Can you compare two strings like string1==string2? Why do we need strcmp()? ·          What does printf() return? ·          What do setjmp() and longjump() functions do? ·          Whats the prototype of main()? Can main() return a structure? ·          Is exit(status) equivalent to returning the same status from main()? ·          Can main() be called recursively? ·          How to print the arguments recieved by main()?

·    STRUCTURES, UNIONS, AND ENUMERATIONS

·          Can structures be assigned to variables and passed to and from functions? ·          Can we directly compare two structures using the == operator? ·          Can we pass constant values to functions which accept structure arguments? ·          How does one use fread() and fwrite()? Can we read/write structures to/from files? ·          Why do structures get padded? Why does sizeof() return a larger size? ·          Can we determine the offset of a field within a structure and directly access  that element? ·          What are bit fields in structures? ·          What is a union? Where does one use unions? What are the limitations of unions?

·    PREPROCESSORS ( MACROS,HEADERS ETC. )

·          How should we write a multi-statement macro? ·          How can I write a macro which takes a variable number of arguments? ·          What is the token pasting operator and stringizing operator in C? ·          Define a macro called SQR which squares a number. ·          What should go in header files? How to prevent a header file being included  twice? Whats wrong with including more headers? ·          Is there a limit on the number of characters in the name of a header file? ·          Is it acceptable to declare/define a variable in a C header?

·    BIT FIDDLING

·          Write a C program to count bits set in an integer? ·          What purpose do the bitwise and, or, xor and the shift operators serve? ·          How to reverse the bits in an interger? ·          Check if the 20th bit of a 32 bit integer is on or off? ·          How to reverse the odd bits of an integer? ·          How would you count the number of bits set in a floating point number?

·    FILE OPERATIONS

·          How do stat(), fstat(), vstat() work? How to check whether a file exists? ·          How can I insert or delete a line (or record) in the middle of a file? ·          How can I recover the file name using its file descriptor? ·          How can I delete a file? How do I copy files? How can I read a directory in a C program? ·          Whats the use of fopen(), fclose(), fprintf(), getc(), putc(), getw(), putw(),  fscanf(), feof(), ftell(), fseek(), rewind(), fread(), fwrite(), fgets(), fputs(), freopen(),  fflush(), ungetc()? ·          How to check if a file is a binary file or an ascii file?

·    COMPILING AND LINKING

·          How to list all the predefined identifiers? ·          How the compiler make difference between C and C++? ·          What are the general steps in compilation? ·          What are the different types of linkages? ·          What do you mean by scope and duration? ·          What are makefiles? Why are they used?

·    LINKED LISTS

·          How do you reverse a singly linked list? How do you reverse a  doubly linked list? Write a C program to do the same. ·          Given only a pointer to a node to be deleted in a singly linked list,  how do you delete it? ·          How do you sort a linked list? Write a C program to sort a linked list. ·          How to declare a structure of a linked list? ·          Write a C program to implement a Generic Linked List. ·          How do you reverse a linked list without using any C pointers? ·          How would you detect a loop in a linked list? Write a C program to  detect a loop in a linked list. ·          How do you find the middle of a linked list? Write a C program to  return the middle of a linked list ·          If you are using C language to implement the heterogeneous linked  list, what pointer type will you use? ·          How to compare two linked lists? Write a C program to compare two  linked lists. ·          How to create a copy of a linked list? Write a C program to create a  copy of a linked list ? ·          Write a C program to free the nodes of a linked list. ·          Can we do a Binary search on a linked list? ·          Write a C program to return the nth node from the end of a linked list. ·          How would you find out if one of the pointers in a linked list is corrupted or not? ·          Write a C program to insert nodes into a linked list in a sorted fashion? ·          Write a C program to remove duplicates from a sorted linked list? ·          How to read a singly linked list backwards? ·          How can I search for data in a linked list?

·    TREES

·          Write a C program to find the depth or height of a tree. ·          Write a C program to determine the number of elements (or size) in a tree. ·          Write a C program to delete a tree (i.e, free up its nodes) ·          Write C code to determine if two trees are identical ·          Write a C program to find the mininum value in a binary search tree. ·          Write a C program to compute the maximum depth in a tree? ·          Write a C program to create a mirror copy of a tree (left nodes become  right and right nodes become left)! ·          Write C code to return a pointer to the nth node of an inorder traversal of a BST. ·          Write C code to implement the preorder(), inorder() and postorder()  traversals. Whats their time complexities? ·          Write a C program to create a copy of a tree ·          Write C code to check if a given binary tree is a binary search tree or not? ·          Write C code to implement level order traversal of a tree. ·          Write a C program to delete a node from a Binary Search Tree? ·          Write C code to search for a value in a binary search tree (BST). ·          Write C code to count the number of leaves in a tree ·          Write C code for iterative preorder, inorder and postorder tree traversals ·          Can you construct a tree using postorder and preorder traversal? ·          Construct a tree given its inorder and preorder traversal strings.  Similarly construct a tree given its inorder and post order traversal strings. ·          Find the closest ancestor of two nodes in a tree. ·          Given an expression tree, evaluate the expression and obtain a  paranthesized form of the expression. ·          How do you convert a tree into an array? ·          What is an AVL tree? ·          How many different trees can be constructed using n nodes? ·          A full N-ary tree has M non-leaf nodes, how many leaf nodes does it have? ·          Implement Breadth First Search (BFS) and Depth First Search (DFS) ·          Write pseudocode to add a new node to a Binary Search Tree (BST) ·          What is a threaded binary tree?

·    SORTING

·          What is heap sort? ·          What is the difference between Merge Sort and Quick sort? ·          Give pseudocode for the mergesort algorithm ·          Implement the bubble sort algorithm. How can it be improved?  Write the code for selection sort, quick sort, insertion sort. ·          How can I sort things that are too large to bring into memory?

C / C++ REFERENCE NOTES

Here I have listed some of the sites I visited.  I found these sites very informative.  If you know any other site that provide useful information on C/C++, and not included in this list, let me know.  Also if any of the site has moved, send me the updated URL.

PROGRAMMING IN C/C++

• C Programming Reference Looking for an online C programmer's reference, Martin Leslie found only tutorials; consequently, he attempted to fill this gap in online C documentation himself. By now, Gary M. Greenberg has stepped in to help maintain the material.
• C++ Annotations Karel Kubat converted the guide that he and Frank B. Brokken wrote for their C++ class at the State University of Groningen from Dutch LaTeX to English HTML.  Destined for readers who are already familiar with C, the subtree covers introductory topics from constructors and destructors and member functions to single and multiple inheritance and virtual functions.   Make it a point to visit this site.
• C Programming Two introductory tutorials; the old course has been rewritten to employ ANSI C.  Smaller than "Programming in C," these are easier on the examples, better formatted, and more evenly written, although they still omit much and blunder occasionally.  I'd stick with K&R.
• ANSI C Programming Phil J Willis' introductory ANSI C tutorial.  Parts of it are not yet fleshed out, parts of it are wrong; but the writing is above average.

• Neil's C++ Stuff A very nice site with tutorials and more information

• From the Ground Up: A Guide to C++A good tutorial that has been around for a long time and is generally pretty accurate.
• Programming Palace Lots of source code for Turbo C++ and for DJGPP
• Snippets Code Collection A lot of code, and it is searchable. You may or may not find what you need, however.
• Darren's Game Programming Site A nice site, give it a look
• 
  

  Some technical reports from Bell Labs. The short and unassuming page offers pearls such as Kernighan's "Why Pascal is Not My Favorite Programming Language", Bjarne Stroustrup's meditation on data hiding "Sixteen Ways to Stack a Cat," and an early stage of Andrew Koenig's "C Traps and Pitfalls".

• A tutorial on pointers and arrays in C Ted Jensen wrote ten chapters about this difficult aspect of C, drawing on his experience discussing pointers and arrays in forums like FidoNet's C Echo and USENET's comp.lang.c newsgroup. He knows his subject and the writing is consistent; if your books and Steve Summit's comp.lang.c FAQ didn't help, perhaps Ted can. (The tutorial'swelcome page also offers HTML and ASCII versions for download.)
• Introduction to Programming in C at Worcester Polytechnic Institute.
• Phil's C Course by Phil Ottewell.
• C Language Tutorial by Gordon Dodrill.
• C and Unix notes by Jon Campbell.

CODING STANDARDS

• NASA Development Coding Standards and Style Guide.
• Recommended C Style and Coding Standards by L.W. Cannon et al.
• C Style and Coding Standards at Los Alamos National Labs.

• C and C++ style guides

Christopher Lott maintains this short, plain page with links to style guides, coding rules, and discussions from USENET.

INFORMATION RESOURCES

• The lysator library.
• The Association of C and C++ Users.
• Learn C/C++ today page maintained by Vinit Carpenter
• Technology Watch: C Archive
• Cera C language resource page.
• C Information supplied by Warwick University.
• Netlib scientific computing repository.
• Archive of the C Users Journal.
• C Programming Resources.
• The C Side by Derek Harper.
• *c:c++ resources by E.J. Inglis-Arkell.

PROGRAMMING NEWSGROUPS:

• alt.comp.lang.learn.c-c++Good group for beginners, plenty of problems that people have while learning.
• comp.lang.c Lots of questions about C programming
• comp.lang.c++ Lots of C++ programming questions.
• comp.graphics.algorithms Lots of graphics algorithms
• comp.os.msdos.djgpp All about DJGPP programming, go here for questions about DJGPP.