Computer Tutorial

.  Which is the subset of SQL commands used to manipulate Oracle Database structures, including tables? Data Definition Language (DDL) 2.       What operator performs pattern matching? LIKE operator 3.       What operator tests column for the absence of data? IS NULL operator 4.       Which command executes the contents of a specified file?              START <filename> or @<filename> 5.       What is the parameter substitution symbol used with INSERT INTO command?              & 6.       Which command displays the SQL command in the SQL buffer, and then executes it?              RUN 7.       What are the wildcards used for pattern matching?              _ for single character substitution and % for multi-character substitution 8.       State true or false. EXISTS, SOME, ANY are operators in SQL.              True 9.       State true or false. !=, <>, ^= all denote the same operation.              True 10.  

Q1. What is SQL? Ans: Structured Query Language 2. What is database? A database is a logically coherent collection of data with some inherent meaning, representing some aspect of real world and which is designed, built and populated with data for a specific purpose. 3. What is DBMS? It is a collection of programs that enables user to create and maintain a database. In other words it is general-purpose software that provides the users with the processes of defining , constructing and manipulating the database for various applications. 4. What is a Database system? The database and DBMS software together is called as Database system. 5. Advantages of DBMS? Ø   Redundancy is controlled. Ø   Unauthorised access is restricted. Ø   Providing multiple user interfaces. Ø   Enforcing integrity constraints. Ø   Providing backup and recovery. 6. Disadvantage in File Processing System? Ø   Data redundancy & inconsistency. Ø   Difficult in accessing d