Let us understand what table, view and synonym in the structured query language (SQL) are.Table, view and synonymA table is a repository of data, where in the table it is a physical entity. A table resides physically in the database.A view is not a part of the database’s physical representation. ... Read More

Delete command is a data manipulation command which is used to remove records from a table. All records may be removed in one go, or a set of records may be deleted based on a condition.Remove specific rows from tableTo remove a specific row in the table, we need to ... Read More

Update command is a data manipulation command which is used to edit the records of a table. It may be used to update a single row based on a condition, all rows or set of rows based on the condition given by the user.It is used along with the SET ... Read More

Insert command is data manipulation commands, which is used to manipulate data by inserting the information into the tables.This command is used to add records to a table. While inserting a record using the insert statement, the number of records being entered should match in the columns of the table. ... Read More

Select command is used to fetch the data in a set of records from a table, view or a group of tables, views by making use of SQL joins.Retrieval of data using SQL statements can be done by using different predicates like −WhereGroup ByHavingOrder ByThe simplest example of a select ... Read More

A file system is a method of storing and organizing the computer files and the data they contain to make it easy to find and access them.Characteristics of file systemThe characteristics of file system are as follows −It is a group of files for storing the data of an organization.Each ... Read More

Before understanding the difference between data and information, let’s have a look at the definitions of data and information with an example.DataData is the raw material that can be processed for any computing machine.For example − Employee name, Product name, Name of the student, Marks of the student, Mobile number, ... Read More

Let’s discuss flat and database definition before understanding the difference between flat files and databases.Flat filesA flat file contains records which have no structured interrelationship. They are typically called as a text file, where all word processing, structure characters and markup have been removed. A flat file represents a table ... Read More

There are two methods for converting deterministic finite automata (DFA) to Regular expression (RE). These are as follows −Arden’s MethodState Elimination MethodLet us understand these methods in detail.Arden’s TheoremLet P and Q be the two regular expressions.If P does not contain null string, then following equation in R, viz R ... Read More

Linear Bounded Automaton (LBA) is a restricted form of Turing Machine in which input tape is finite.ExampleProve that LBA ⊂ PSPACEPSPACE is a superset of the set of context-sensitive languages.Now to prove LBA=PSPACE, We use theorem of Space compression with tape reduction which states that, For every k-tape S(n) space-bounded ... Read More