Personal View #1

Personal View #9

2008-09-07T01:33:00.000-07:00

Difference between a database record and a database field.

A database record is a row of data in a database table consisting of a single value from each column of data in the table. The data in the columns in a table are all of the same type of data, whereas the rows represent a given instance while,a database feild is a certain part of a database,containing specific information.

Difference between a memory variable and a database field.

Memory variable names must begin with a letter (A-Z, a-z) or an underscore (-), followed by any combination of letters, digits or underscores. The variable name can be of any length, but only the first ten characters are significant, so these must be unique while a database field is a part of a record held in a database,containing specific information.

Personal View #8

2008-08-25T01:41:00.000-07:00

History of SQLite:

SQLite is a mostly ACID-compliant relational database management system contained in a relatively small (~500kB) C programming library.

Unlike client-server database management systems, the SQLite engine is not a standalone process with which the program communicates. Instead, the SQLite library is linked in and thus becomes an integral part of the program. The program uses SQLite's functionality through simple function calls, which reduces latency in database access as function calls are more efficient than inter-process communication. The entire database (definitions, tables, indices, and the data itself) is stored as a single cross-platform file on a host machine. This simple design is achieved by locking the entire database file at the beginning of a transaction.

SQLite was created by D. Richard Hipp, who sells training, direct technical support contracts and add-ons such as compression and encryption. The source code for SQLite is in the public domain.

The program was originally developed by Mauricio Piacentini from Tabuleiro Produções, a Brazilian company, as the Arca Database Browser. The original version is a free companion tool to Arca Database Xtra, a commercial product that embeds SQLite databases with some additional extensions for handling of compressed and binary data.
The original code was later adjusted to be compatible with standard SQLite 2.x databases. The resulting program was renamed SQLite Database Browser, and released into the public domain by the original author. Icons were contributed by Raquel Ravanini, also from Tabuleiro.

Personal View # 7

2008-08-14T01:16:00.000-07:00

A. Rules of Normalization
1.Eliminate Repeating Groups - Make a separate table for each set of related attributes, and give each table a primary key.

2.Eliminate Redundant Data - If an attribute depends on only part of a multi-valued key, remove it to a separate table.

3.Eliminate Columns Not Dependent On Key- If attributes do not contribute to a description of the key, remove them to a separate table.

4.Boyce-Codd Normal Form - If there are non-trivial dependencies between candidate key attributes, separate them out into distinct tables.

5.Isolate Independent Multiple Relationships - No table may contain two or more 1:n or n:m relationships that are not directly related.

6.Isolate Semantically Related Multiple Relationships - There may be practical constrains on information that justify separating logically related many-to-many relationships.

7.Optimal Normal Form - a model limited to only simple (elemental) facts, as expressed in Object Role Model notation.

8.Domain-Key Normal Form - a model free from all modification anomalies.

B. How would this be applied into the DBMS in the software that you are assigned?-SQLite

SQLite uses an unusual type system for an SQL DBMS.
-instead of assigning a type to a column as in most SQL database systems, types are assigned to individual values.Like in language terms it is dynamically typed. Moreover, it is weakly typed in some of the same ways that Perl is: one can insert a string into an integer column (although SQLite will try to convert the string to an integer first, if the column's preferred type is integer).

- this adds flexibility to columns, especially when bound to a dynamically typed scripting language. However, the technique is not portable to other SQL databases. The inability to have strictly typed columns, as in typical databases, is a common criticism. The SQLite web site describes a "strict affinity" mode, but this feature has not yet been added.Several computer processes or threads may access the same database without problems. Several read accesses can be satisfied in parallel. A write access can only be satisfied if no other accesses are currently being serviced, otherwise the write access fails with an error code or can automatically be retried until a configurable timeout expires. This concurrent access situation would change when dealing with temporary tables.

-a standalone program called sqlite3 is provided which can be used to create a database, define tables within it, insert and change rows, run queries and manage an SQLite database file. This program is a single executable file on the host machine. It also serves as an example for writing applications that use the SQLite library.

Personal View #6

2008-07-12T03:37:00.000-07:00

Choose a DBMS:discuss how its database structure and entry forms are created.

ORACLE DBMS

Oracle database system comprises at least one instance of the application, along with data storage. An instance comprises a set of operating-system processes and memory-structures that interact with the storage. Typical processes include PMON (the process monitor) and SMON (the system monitor).
The Oracle RDBMS stores data logically in the form of tablespaces and physically in the form of data files. Tablespaces can contain various types of memory segments. For example: Data Segments, Index Segments and others. Segments in turn comprise one or more extents. Extents comprise groups of contiguous data blocks,whileData blocks form the basic units of data storage. At the physical level, data-files comprise one or more data blocks, where the blocksize can vary between data-files.

Oracle database management tracks its computer data storage with the help of information stored in the SYSTEM tablespace. The SYSTEM tablespace contains the data dictionary— and often indexes and clusters. A data dictionary is consists of a special collection of tables that contains information about all user-objects in the database.
Memory Architecture(System Global Area)
Each Oracle instance uses a System Global Area or SGA or a shared-memory area, to store its data and control-information. Each Oracle instance allocates itself an SGA when it starts and de-allocates it at shut-down time.
The SGA contains of the ff. elements:
- database buffer cache: this stores the most recently-used data blocks. These blocks can contain modified data not yet written to disk unmodified blocks, or blocks written to disk since modification.
- redo log buffer: this stores redo entries — a log of changes made to the database.
- shared pool: this area of the SGA stores shared-memory structures such as shared SQL areas in the library cache and internal information in the data dictionary.

Library cache
The library cache stores shared SQL, caching the parse tree and the execution plan for every unique SQL statement.
Data dictionary cache
The data dictionary comprises a set of tables and views that map the structure of the database.
Program Global Area
The Program Global Area or PGA memory-area contains data and control-information for Oracle's server-processes,the size and content of the PGA depends on the Oracle-server options installed.
Process architecture
The Oracle RDBMS typically relies on a group of processes running simultaneously in the background and interacting to further and monitor database operations.

Personal View #5

2008-07-06T01:25:00.000-07:00

A.Contrast the different database models:

Hierarchical Model
-the hierarchical data model organizes data in a tree structure. There is a hierarchy of parent and child data segments. This structure implies that a record can have repeating information, generally in the child data segments. It collects all the instances of a specific record together as a record type. To create links between these record types, the hierarchical model uses Parent Child Relationships while;
Network Model
-coincided with the popularity of the hierarchical data model. That's why some data were more naturally modeled with more than one parent per child. So, the network model permitted the modeling of many-to-many relationships in data,on the other hand;
Relational Model(RDBMS - relational database management system)
-is a database based on the relational model developed by E.F. Codd. A relational database allows the definition of data structures, storage and retrieval operations and integrity constraints. In a database, the data and relations between them are organised in tables. A table is a collection of records and each record in a table contains the same fields meanwhile;
Object/Relational ModelObject/relational database management systems (ORDBMSs)
-adds new object storage capabilities to the relational systems at the core of modern information systems. These new facilities integrate management of traditional fielded data, complex objects such as time-series and geospatial data and diverse binary media such as audio, video, images, and applets. By encapsulating the methods with data structures, an ORDBMS server can execute complex analytical and data manipulation operations to search and transform multimedia and other complex objects while;
Object-Oriented Model
- which is having Object DBMSs, adds database functionality to object programming languages. Object DBMSs extend the semantics of the C++, Smalltalk and Java object programming languages to provide full-featured database programming capability, while retaining native language compatibility. One of the major benefit of this approach is, the unification of the application and database development into a seamless data model and language environment. As a result, applications require less code, use more natural data modeling, and code bases are easier to maintain on the other hand;
Semistructured Model
- is normally associated with a schema which is contained within the data,and sometimes called "self-describing''. In such database there is no clear separation between the data and the schema, and the degree to which it is structured depends on the application meanwhile;
Associative Model
-divides the real-world things about which data is to be recorded into two sorts, first is:
1.Entities are things that have discrete, independent existence. An entity’s existence does not depend on any other thing,second is:
2.Associations are things whose existence depends on one or more other things, such that if any of those things ceases to exist, then the thing itself ceases to exist or becomes meaningless while;
Entity-Attribute-Value (EAV) data model
- is the best way to understand the rationale of EAV design of which EAV is a generalized form. Let us consider a supermarket database that must manage thousands of products and brands,one stores product descriptions in a Products table:which contains purchases/sales of individual items that are recorded in other tables as separate rows with a product ID referencing the table.An EAV design involves a single table with three columns,which includes an entity (such as an olfactory receptor ID), an attribute (such as species, which is actually a pointer into the metadata table) and a value for the attribute lastly;
Context Model
-combines features of all the above models. It can be considered as a collection of object-oriented, network and semistructured models or as some kind of object database. In other words this is a flexible model, we can use any type of database structure depending on task.

B.Discuss the management activities DBMS perform upon data:

One of the management activities DBMS perform upon data is a modeling language.This is to define the schema of each database hosted in the DBMS.The most common types of organizations are the hierarchical,network,relational and object models.The optimal structure depends on the natural organization of the application's data, and on the application's requirements which include transaction rate (speed), reliability, maintainability, scalability, and cost.Another is the data structures that includes fields,records,files and objects.Which is optimized to deal with very large amounts of data that is stored on a permanent data storage device which implies relatively slow access compared to volatile main memory.Another one is the database query language and report writer to allow users to interactively interrogate the database, analyze its data and update it according to the user's privileges on data.It also controls the security of the database.Lastly is the transaction mechanism,in order to ensure data integrity,despite the concurrent user accesses and faults.It also maintains the integrity of the data in the database.

Personal View #4

2008-07-06T00:01:00.000-07:00

A.Identify at least 10 DBMS software with their corresponding developer.
B.Choose one and briefly detail:how does this DBMS handle and/or accommodate data input.

1.Easy Base
is the ultimate development in DOS data management. The interface is simple enough for a complete novice to get started in data programming yet the query language and function library provide all the power required by professional developers.
-Developer: Easy Software Ltd.

2.CompareData
is a native Windowsâ„¢ cross-dbms application that allows you to visually compare and synchronize data between two SQL databases using ODBC drivers. We can also retrieve all/some data for a table/view from the two databases and compare the data visually to see differences highlighted on the screen.
-Developer: Zidsoft

3.Visual SQL-Designer
is a program for easy visual constructing hard SQL-query for any database and write it. It support ORACLE, MSSQL 6.5-2000, MySQL, SyBase, Db2 for NT, MSAccess and other ODBC databases.
-Developer: VisualSoft

4.IPTunnelManager
the program IPTunnelManager is used for IP tunneling with the options for compressing and encrypting traffic.Therefore,the program makes it possible to create a secure connection for any application or service using TCP/IP (HTTP, FTP, SMTP, POP, NNTP, SNPP, Telnet.
-Developer: Pavel Aronovich

5.Database Web Explorer
a database Web Explorer is Web-based database manager and it is intended for work with DBMS in Internet or Intranet networks,using as the client-application a usual Web-browser.This is universal solution for remote access through Internet or Intranet to database.
-Developer: Anatoly A. Sadovsky

6.Alventis
a Universal Information Manager is an unlimited number of table structures, data-entry forms, banded reports that are user-customizable with simple drag-and-drop. Fast searches are using full-text indexing,and client or server multi-user security, all without programming.
-Developer: Alventis Corporation

7.WebCab Functions for Delphi
this adds refined numerical procedures to either construct a function of one or two variables from a set of points, or solve an equation of one variable, to your .NET, COM and XML Web service Applications.
-Developer: WebCab Components

8.AppGini Free Trial Version
AppGini generates PHP database applications for MySQL.It creates tables, view, add, edit, delete, sort and filter records.It supports CSS for customizing scripts appearance.
-Developer: BigProf Software

9.Database Architect
defines database tables, fields, references, and generate the database. When working with Database Architect, software developer defines database structure, drawing it directly in the program's window and generates the DB directly from the program.
-Developer: Guru Developers

10.SQL Developer
is a database programmer's workplace used to create and execute SQL queries and scripts, debug script execution, view results and manage databases. It is compatible with any SQL database namely Oracle, MS SQL, DBF, Access, Paradox.
-Developer: Guru Developers

B.DATABASE ARCHITECT

When your dealing with Database Architect,you can store here database format specifications like data types,table,reference,index creation commands in the external text files.It also allows not only to update or edit specifications but even to add new database descriptions to the program.Database Architect uses WYSIWYG principles for diagram building. For example, if you need to add a new database table to your database, you click the table icon on the program's toolbar, then place it in the model window and define all necessary table properties like table name, fields, indexes in the table properties dialog.

Personal View #3

2008-06-28T04:25:00.000-07:00

A.Discuss and Interrelate the ff:
Data-Datatype
Data refers to the raw materials or the unprocessed data that are used by the computer for processing while;
Datatype refers to the set of values and operations.It is also an attribute of a datum bmswhich tells the computer something about the kind of datum it is.
The two are related because the data contains a certain datatype.It could be one of them that is in the data.String,integers,character,and float are the datatype.

Data-Database
Database is a structured collection of records or data.Data is concerned with database because the data here are structuredly collected and is used for variety of applications.

DBMS-Database
DBMS is a set of programs that provides access to the database.Database is connected to DBMS because if there's no DBMS, the collected data in the database will be useless,for the reason that there's no program that is providing access to the data, so that the it can be use.

Data-DBMS
DBMS is a set of software programs that controls the organization,storage,management,and retrival of data in database.Without DBMS,the data in the database will not be arranged,they will be disorganized,and there's no software that is managing the data in the database.

DBMS-Datatype
DBMS is connected with datatype because DBMS is categorized according to their data structures or types.

B.
1.Why we input data?
We input data to the computer so that the computer has something to processed into information and can be turned into something useful.

2.Why we process data?
We process data so that we could come up with an information or knowledge from the processed data.The processing of data is usually assumed to be automated and running on a computer.Because these data are most useful when well-presented and informative.

3.Output-for what purpose?
Output refers to the finished product of the processed data.It could be in the form of printed paper,video and audio.It is an outcome of what you have inputted.And is converted into a useful thing or a reference.

Personal View #2

2008-06-28T04:19:00.000-07:00

Discuss and interrelate the following:
1.What is Data?
Data is a collection of unorganized facts that have not yet been processed into information.It is also the raw material to proceed by a computer.
2.What is a Data type?
Data type is define as a set of values and the allowable operations on those values.It is also an attribute of a datum which tells the computer(and the programmer)something about the kind of datum it is.
3.What is a Database?
Database is defined as a collection of integrated data that can be use for a variety of applications.It is also a structured collection of records or data.
4.What is DBMS?
Database Management system or DBMS are the software used to organize and maintain the database.It is also defined as a collection of integrated data that can be use for a variety of applications.

Personal View #1

2008-06-21T05:47:00.000-07:00

A.Importance of OS.
The importance of OS is that it operates the programs in the computer.And according to my research,OS is a set of programs that manipulates and manages the computer system.

B.Differentiate OS from an application system.
An OS is the one that operates the programs in the computer while an application software is a set of programs that is applied in the computer.

C.What do you intend to do in life and why did you enroll in this course?
What I intend to do in life is to have a stable job someday.I want to apply in a call center agency because I want to apply my ideas in my college years of learning.I enroll in this course because I want to know what is a computer and what makes up a computer.

D.Briefly describe yourself.
I am Jezza Bartolata,18 years of age.Currently residing at Mangnao,Dumaguete City.I am taking up Bachelor of Science in Informaton Technology and is a sophomore in this university.My motto in life is "Learn to grow,where you are planted".