Database Programming

There are several advantages of DBMS:

1. Redundancy problem can be solve

2. Security level is high

3. Referential Integrity

4. Multi user Access

5. Data Independence

By Sushil Kumar Sinha

The complexity of binary search tree :

Search , Insertion and Deletion is O(h) . and the Height can be of O(n) ( if the tree is a skew tree).

For Balanced Binary Trees , the Order is O(log n).

Traditional file processing system lacks from DBMS in many ways . Major Disadvantage of FPS are it do not maintains data security and integrity efficiently.

An entity is something that exists by itself, although it need not be of material existence.

reduce the chance of false identification.----apex

The main difference between ADODC and ADODB is that whereas ADODB is a class library, ADODC is just but a data control. The other difference is that ADODC uses the system resources more compared to the ADODB.

3rd normal form can remove transitive dependencies. for example, group city and group supervisor are depending on a non.key field group number.

dBw=dBm-30 then 75-30=45 dBw dBw=dBm-30 then 75-30=45 dBw dBw=dBm-30 then 75-30=45 dBw

hello

Computerized payroll systems are much faster and easier compared to the manual processing......

Also quick and accurate answers are produced by the computerized software

What_are_the_primary_role_of_technocrats_and_managers_play_in_actualizing_the_data_processing_need

with data redundancy there willbe more wastage of memory space as same type of data willbe saved many times

when to want to see the data all duplicate results will come

whatever i cnt b askd, anyway innit

A one-to-many relationship means that one row in one of the tables will relate directly to many rows in the other table.

1. Designing of the database structure. This is by helping in determinig the design of the database information and contents.

2. He/She decide information contents of the database. Deciding the storage structure and acces strategy.

database is the collection of information that store in known procedure

ACID (an acronymn for Atomicity Consistency Isolation Durability) is a concept that Database Professionals generally look for when evaluating databases and application architectures. For a reliable database all this four attributes should be achieved. Atomicity is an all-or-none proposition. Consistency guarantees that a transaction never leaves your database in a half-finished state. Isolation keeps transactions separated from each other until they’re finished. Durability guarantees that the database will keep track of pending changes in such a way that the server can recover from an abnormal termination. Above four rules are very important for any developers dealing with databases. Ref: http://blog.sqlauthority.com/2007/12/09/sql-server-acid-atomicity-consistency-isolation-durability/ - ACID (atomicity, consistency, isolation, and durability) is an acronym and mnemonic device for learning and remembering the four primary attributes ensured to any transaction by a transaction manager (which is also called a transaction monitor). These attributes are: Atomicity. In a transaction involving two or more discrete pieces of information, either all of the pieces are committed or none are. Consistency. A transaction either creates a new and valid state of data, or, if any failure occurs, returns all data to its state before the transaction was started. Isolation. A transaction in process and not yet committed must remain isolated from any other transaction. Durability. Committed data is saved by the system such that, even in the event of a failure and system restart, the data is available in its correct state. The ACID concept is described in ISO/IEC 10026-1:1992 Section 4. Each of these attributes can be measured against a benchmark. In general, however, a transaction manager or monitor is designed to realize the ACID concept. In adistributed system, one way to achieve ACID is to use a two-phase commit(2PC), which ensures that all involved sites must commit to transaction completion or none do, and the transaction is rolled back (see rollback). Ref: http://searchsqlserver.techtarget.com/sDefinition/0,,sid87_gci213756,00.html

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Primary file organization is the way in which we determine how the file records are physically placed on the disk and hence, how the records can be accessed. Unordered means that there is no particular order in this way, i.e. a heap algorithm is used.

British Petroleum.

Technically it's an acronym not an abbreviation. An abbreviation is a shortened version of a word, such as abbr. for abbreviation. An acronym is any combination of abbreviations, contractions or initialisms. BP is an initialism and is therefore an acronym.

The relationships between database applications DBMS and databases is as follows:

Databases can be simple or complex. simple databases can be kept in a Microsoft Excel spreadsheet or they can be maintained in a user generated Microsoft Access database which can be programmed to query certain data that has been entered into that database over a period of time. Microsoft Excel and Microsoft Access are also applications that are used to build databases that can be incorporated into DBMS or Database Management Systems. These systems can be extremely complex or they can be simple meaning that maintenance to these systems is not demanding. If the DBMS is complex it may require an entire team of technicians and in some cases engineers.The relationship between users, database applications, databases, and Database Management Systems can be simplified even further - Users can access a database that has been created with a database application to query managed data that is a part of a uniform Database management system.

Database Instance

The term instance is typically used to describe a complete database environment, including the RDBMS software, table structure, stored procedures and other functionality. It is most commonly used when administrators describe multiple

instances of the same database.Also Known As: environment

Examples: An organization with an employees database might have three different

instances: production (used to contain live data), pre-production (used to test new

functionality prior to release into production) and development (used by

database developers to create new functionality).

RELATION SCHEMA

A relation schema can be thought of as the basic information describing

a table or relation. This includes a set of column names, the data types associated

with each column, and the name associated with the entire table. For example, a

relation schema for the relation called Students could be expressed using the

following representation:

Students(sid: string, name: string, login:

string, age: integer, gpa: real)

There are five fields or columns, with names and types as shown above.

Sequential numbers appear sometimes on channel buoys

A Database has three views.

The External Schema: What the end user sees.

The Internal Schema: What the programmers of the program see.

The Conceptual Schema: The basic plan of the database. Most of the time this is in paper form as a Conceptual Schema Diagram (CSD)