MySQL

In VHDL, entity is the keyword for defining a new object. In SGML and its derived markup languages HTML and XML, an entity is a named body of data associated with a document. Once defined, an entity can be referenced any number of times within the document, via entity references. An entity typically consists of a sequence of one or more characters, either encapsulated within a declaration of the entity's existence, or encoded and stored externally in a text file. Such entities and their references are comparable to macros and include files in programming languages. However, entities don't necessarily have to contain parseable text; they may also be binary files that are included in a document only by reference, with the entity name as the value of an ENTITY-type attribute.

Answer:

An entity is something that has a distinct, separate existence, though it need not be a material existence. In particular, abstractions and legal fictions are usually regarded as entities. In general, there is also no presumption that an entity is animate. Entities are used in system developmental models that display communications and internal processing of, say, documents compared to order processing.

An entity could be viewed as a set containing subsets. In philosophy, such sets are said to be abstract objects.

Sometimes, the word entity is used in a general sense of a being, whether or not the referent has material existence; e.g., is often referred to as an entity with no corporeal form, such as a language. It is also often used to refer to ghosts and other spirits. Taken further, entity sometimes refers to existence or being itself. For example, the former U.S. diplomat George F. Kennan once said that "the policy of the government of the United States is to seek . . . to preserve Chinese territorial and administrative entity.

Answer:

An entity is a legally recognized and formally structured grouping of people focused on some common cause or objective.

Examples

Here are some examples of entities:

SIL

an SIL branch

UNESCO

Oracle includes numerous data structures to improve the speed of Oracle SQL queries. Oracle includes many new indexing algorithms that dramatically increase the speed with which Oracle queries are serviced like b-tree index, bitmap indexes, function-based indexes, and index-only tables (IOTs

Oracle uses indexes to avoid the need for large-table, full-table scans and disk sorts, which are required when the SQL optimizer cannot find an efficient way to service the SQL query. I begin our look at Oracle indexing with a review of standard Oracle b-tree index methodologies.

It all depends on the type of MySQL database you wish to use and also the operating system the server has. Most of the restraints are due to the max file size the operating system can store. The limits are done by table size rather than the database size as a whole.

• Win 32 w/ FAT/FAT32 - 2GB/4GB
• Win 32 w/ NTFS - 2TB (possibly larger)
• Linux 2.2-Intel 32-bit - 2GB (LFS: 4GB)
• Linux 2.4+ - (using ext3 file system) 4TB
• Solaris 9/10 - 16TB
• MacOS X w/ HFS+ - 2TB
• NetWare w/NSS file system - 8TB

InnoDB tables are often split up into multiple files to allow larger tables, this is known as a tablespace. The maximum table space is 64TB.

MyISAM tables default size is at 4GB, but this can be changed to a maximum of 65,536TB.

Different types of attributes in DBMS are:

• Key or non key attributes

• Required or optional Attributes

• Simple or composite Attributes

• Single-valued and multi-valued Attributes

• Stored, Coded or derived Attributes

DBMS Interfaces

User-friendly interfaces provided by a DBMS may include the following. � Menu-Based interfaces for Web Clients or Browsing: These interfaces present user with lists of options, called menus, that lead the user through the formulation a request. Menus do away with the need to memorize the specific commands and syntax of a query language. Pull-down menus are a very popular technique in Web based user interfaces. They are also often used in browsing interfaces, which allows a user to look through the contents of a database. � Forms-Based Interfaces: A forms-based interface displays a form to each user. Forms are usually designed and programmed for naive users as interfaces to canned transactions. Some systems have utilities that define a form by letting the end user interactively construct a sample form on the screen. � Graphical User Interfaces: A graphical interface (GUI) typically displays a schema to the user in diagrammatic form. The user can then specify a query by manipulating diagram. In many cases, GUls utilize both menus and forms. Most GUls use a pointing device, such as a mouse, to pick certain parts of the displayed schema diagram. � Natural Language Interfaces: These interfaces accept requests written in English, Hindi or some other language and attempt to "understand" them. A natural language interface usually has its own "schema," which is similar to the database conceptual schema, as well as a dictionary of important words. � Interfaces for Parametric Users: Parametric users, such as bank tellers, often have a small set of operations that they must perform repeatedly. Systems analysts and programmers design and implement a special interface for each known class of na�ve users. Usually, a small set of abbreviated commands is included, with the goal of minimizing the number of keystrokes required for each request. For example, function keys in a terminal can be programmed to initiate the various commands. � Interfaces for the DBA. Most database systems contain privileged commands that can be used only by the DBA's staff. These include commands for creating account, setting system parameters, granting account authorization, changing a schema, and reorganizing the storage structures of a database.