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.
Saturday, July 12, 2008
Sunday, July 6, 2008
Personal View #5
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.
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
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.
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.
Subscribe to:
Posts (Atom)
