கணனியின் வேகத்தை அதிகரிக்க 10 வழிகள்

கணனியின் வேகத்தை அதிகரிக்க 10 வழிகள்

இன்றைய தொழில்நுட்ப உலகில் பெரும்பாலோனார் கணனி பயன்படுத்துகிறோம். பல நேரங்களில்  இக்கணனியின் வேகம் குறைந்து நம்மை எரிச்சலூட்டுகின்றன.
எனவே உங்கள் கணனியின் வேகத்தை அதிகரிக்கப்பதற்கான 10 வழிகளைக் காண்போம்.
1. உங்கள் கணனியின் RAM எனப்படும் Random Access Memoryன் அளவை அதிகப்படுத்தவும். ஒரு சாதாரண கணனிக்கு 1GB போதுமானது. அதன் நினைவகத்தின் அளவை அதிகரிக்க அதிகரிக்க வேகமும் அதிகரிக்கும். இப்போது RAM ன் விலை மிகவும் மலிவுதான்.
2. கணனியில் ஏற்கனவே நிறுவியிருக்கக் கூடிய தேவையற்ற மென்பொருட்களை நீக்கிவிடுங்கள் . புதிதாகக் கணனி வாங்கியிருந்தால் கூட அத்துடன் ஏராளமான தேவையற்ற மென்பொருட்களையும் நிறுவி இருப்பார்கள்.

அவற்றில் சில மென்பொருட்கள் மட்டுமே நமக்குப்பயன்படும். மீதி அனைத்தையும் நிராகரித்து நீக்கிவிடவும்.
பழைய கணனியிலும் தேவையற்ற மென்பொருட்கள் இருப்பின் அனைத்தையும் நீக்கிவிடவும். அவற்றிற்குரிய Copy இருந்தால் அதை மட்டும் CD / DVD ல் ஏற்றி burn செய்துகொள்ளவும்.
3. FireFox, Chrome, IE என்று ஒன்றுக்கு மேற்பட்ட browsersஐ நிறுவி இருந்தால் அவற்றில் ஏதேனும் ஒன்றை மட்டும் வைத்துக்கொண்டு மீதியை uninstall செய்துவிடவும்.
4. G-Talk, Yahoo Messenger, Live Messenger என்று ஒன்றுக்கு மேற்பட்ட அரட்டை அடிக்கும் பயன்பாடுகளைத் தனித்தனியாக நிறுவி இருந்தால் எல்லாவற்றையும் uninstall செய்துவிட்டு, digsby (http://www.digsby.com/) போன்ற ஒரே ஒரு instant messenger (நேரடி அரட்டை அரங்கம்) ஐ நிறுவிக் கொள்ளவும்.
5. கணனியில் Windows இயங்குதளமானது boot ஆகும்போது நிறையப் பயன்பாடுகளும் இணைந்தே தொடங்கும். இதற்கு auto startup என்று பெயர்.
இப்படி ஏராளமான பயன்பாடுகளும் விண்டோஸ் இயங்குதளத்துடன் தொடங்கினால் அதன் வேகம் மிகக் குறைந்துவிடும். http://www.revouninstaller.com/ பயன்படுத்தி தேவையற்ற தானியங்கிப் பயன்பாடுகளைக் கழித்துவிடவும்.
6. Startup Delayer ஐ இறக்கி அதைப் பயன்படுத்தி Autoloading பயன்பாடுகளை நீக்கிவிடலாம்.
7. Windows பயனர்கள் அதன் தேவையில்லாத animation தொந்தரவுகளால் அதன் வேகம் குறைவதை உணர்ந்திருப்பார்கள். MyComputerல் right click செய்து, advanced tabல் settingsல், Performanceல் Animate WindowsWhen minimizing and maximizing என்கிறதை disable செய்யவும். மேலும் தேவையில்லாதவற்றையும் disable செய்யவும்.
8. Desktopல் இருக்கும் குறுக்குவழிச் சுட்டிகளுக்கான படங்களை அகற்றிவிடலாம். எனது நண்பர் ஒருவர் 50க்கு மேற்பட்ட desktop icons வைத்திருந்தார். அதனாலேயே அவரது கணனியின் வேகம் மிகக் குறைந்தது. தேவையில்லாத desktop ஐகான்ஸ் எல்லாவற்றையும் நீக்கியபின்னர் கணனியின் வேகம் அதிகரித்தது.
9. கணனியில் ஒரு நெருப்புச்சுவர் (firewall), வைரஜ்எதிர்ப்பான் (anti virus), ஸ்பைவேர் எதிர்ப்பான் (anti spyware) கண்டிப்பாகத் தேவை. அவற்றை அடிக்கடி புதுப்பித்துக்க கொண்டே இருக்கவேண்டும்.
10. ஆனால் இணையத்துடன் இணைந்திருக்காத தனிக் கணனிகள் மற்றும் வெளியிடத்து Floppy, CD, DVD, Pen Drive போன்றவற்றை அனுமதிக்காத கணனிகளில் மேலே கூறிய firewall, antivirus, antispyware போன்ற எதுவும் நிறுவாமல் இருந்தால் அதன் வேகம் மும்மடங்கு ஆகும் என்பதில் ஐயமில்லை

Meta Data:

Meta data is “data about data”. An item of metadata describes the specific characteristics about an individual data item. In databases, metadata describes the structural components of tables and their elements. For example, metadata about an element could include data types, name of data, size and many more characteristics about that element. It would also give information about the tables the database is storing, information, such as length of fields, number of columns, where the tables are located and other pertinent information. One of the main uses for met data is to provide a link between the information creator and the information users. Meta data allows the users to speed up the search for individual data. This is done by being able to set parameter for searches, allowing the filtering of unwanted information. Meta data can be stored either internally, in the same file as the data or externally, in a separate area. Both have advantages and disadvantages. I f the data is stored internally, the meta data is together with the data making more easily accessible to view or change. However, this method creates high redundancy. If metadata is stored externally, the searches can become more efficient. There is no redundancy but getting to this metadata may be a little more technical. There are certain formats that most be used, such as Uniform Resource Identifier(URI) to get to the meta data, if this format is not used the meta data becomes in accessible. All the metadata is stored in a data dictionary or a system catalog. All programs that access data in the database work through a DBMS. The DBMS use the data dictionary to look up the required components and relationships. Any changes made to the database structure are automatically recorded in the data dictionary. This makes the data dictionary manager’s job a lot easier, because any modification of programs that are affected by changed structure is not necessary.

UPDATE

Metadata

Metadata at the most basic level is simply defined as “data about data”. An item of metadata describes the specific characteristics about an individual data item. In the database realm, metadata is defined as, “data about data, through which the end-user data are integrated and managed.” (Rob & Coronel, 2009)  Metadata in a database typically store the relationships that link up numerous pieces of data.  “Metadata names these fields, describes the size of the fields, and may put restrictions on what can go in the field (for example, numbers only).” (Sheldon, 2001).

“Therefore, metadata is information about how data is extracted, and how it may be transformed. It is also about indexing and creating pointers into data. Database design is all about defining metadata schemas.” (Sheldon, 2001)  Meta data can be stored either internally, in the same file as the data, or externally, in a separate area.  If the data is stored internally, the metadata is together with the data, making it more easily accessible to view or change. However, this method creates high redundancy. If metadata is stored externally, the searches can become more efficient. There is no redundancy but getting to this metadata may be a little more technical.

All the metadata is stored in a data dictionary or a system catalog. The data dictionary is most typically an external document that is created in a spreadsheet type of document that stores the conceptual design ideas for the database schema.  The data dictionary also contains the general format that the data, and in effect the metadata, should be.  Metadata is an essential aspect to database design, it allows for increased processing power, due to the fact that it can help create pointers and indexes. 

This image is an example of a database schema that includes the metadata type that it is as well as the information it is, including the size of information it can hold.

Added by Buck9544

Rob, P., & Coronel, C. (2009). Database Systems Design, Implementation, And Management. Boston: Course Technology.

Sheldon, T. (2001). Metadata. Retrieved 12 03, 2009, from Linktionary: http://www.linktionary.com/m/metadata.html

UPDATE 10/14/2011

Definition

Metadata is defined as data that describes other data. Metadata can be divided into two main types: structural and descriptive. Structural metadatadescribes the design structure and their specifications. This type of metadata describes the containers of data within a database. Descriptive metadatadescribes instances of application data. This is the type of metadata that is traditionally spoken of and described as “data about the data.” A third type is sometime identified called Adminitstrative metadata. Administrative metadata provides information that helps to manage other information, such as when and how a resource was created, file types and other technical information.

Metadata makes it easier to retrieve, use, or manage information resources by providing users with information that adds context to the data they’re working with. Metadata can describe information at any level of aggregation, including collections, single resources, or component part of a single resource. Metadata can be embedded into a digital object or can be stored separately

Web pages contain metadata called metatags.

Examples:

e.g. A .mp3 audio file contains metadata that describes the length of the song, the artist, etc.

e.g. A word document contains metadata such as last time modified, length, author, etc.

References

http://www.niso.org/publications/press/UnderstandingMetadata.pdf

http://en.wikipedia.org/wiki/Metadata

System catalog in DBMS: Tracking details of database objects

System catalog is a collection of tables in a database which are used by the DBMS for describing the structure of the database. System catalog is created automatically whenever a database is created. System catalogs can also be accessed by the users of the database. A user can access the system catalog to get more info about the structure of a database. However, a user can only read the system catalog and he can’t modify it. Since modifying the system catalog will result in the modification of the structure of the entire database. System catalog can also be used to access query tools where a user can select different tables easily.

System catalog tracks the details of the following database objects:

1) Columns: System catalog maintains all the necessary information related to every column in a database. For Example, name of a column, associated table, size, data type, etc.

2) Tables: A system catalog maintains all the necessary information related to every table in a database. For Example: name of a table, owner, size, number of columns, etc.

3) Views: System catalog maintains all the necessary information related to every view in a database. For Example: name, owner, query which defines the view, etc.

4) Users: System catalog maintains all the necessary information related to every user in a database. For Example: user name, password, etc.

5) Privileges: It maintains all the necessary information related to every set of privileges in a database. For Example: name of grantor, name of grantee, privileges granted, object on which privileges are granted, etc.

       Database Design Process

01.What are the stages of database system development life cycle?

        I.            Database planning

      II.            System definition

    III.            Requirements collection and analysis

    IV.            Database design

      V.            DBMS selection

    VI.            Application design

  VII.            Prototyping

VIII.            Implementation

    IX.            Data conversion and loading

      X.            Testing

    XI.            Operational maintenance

02.What are the main responsibilities of each stage?

        I.            Database planning:  

§  Management activities that allow stages of database system development lifecycle to be realized as efficiently and effectively as possible.

§  Must be integrated with overall IS strategy of the organization.

§  Database planning should also include development of standards that govern;

ü  how data will be collected

ü  how the format should be specified

ü  what necessary documentation will be needed

ü  how design and implementation should proceed.

      II.            System definition:

§  Describes scope and boundaries of database system and the major user views.

§  User view defines what is required of a database system from perspective of:

ü  a particular job role (such as Manager or Supervisor) or enterprise application area (such as marketing, personnel, or stock control)

    III.            Requirements collection and analysis:

§  Process of collecting and analyzing information about the part of organization to be supported by the database system, and using this information to identify users’ requirements of new system.

§  Information is gathered for each major user view including;

ü  a description of data used or generated

ü  details of how data is to be used/generated

ü  any additional requirements for new database system.

§  Information is analyzed to identify requirements to be included in new database system. Described in the requirements specification.

§  Another important activity is deciding how to manage the requirements for a database system with multiple user views.

   IV.            Database design:

§  Process of creating a design for a database that will support the enterprise’s mission statement and mission objectives for the required database system.

§  Main purposes of data modeling include;

ü  to assist in understanding the meaning (semantics) of the data

ü  to facilitate communication about the information requirements.

§  Building data model requires answering questions about entities, relationships, and attributes.

     V.            DBMS selection :

§  Selection of an appropriate DBMS to support the database system.

§  Undertaken at any time prior to logical design provided sufficient information is available regarding system requirements.

§  Main steps to selecting a DBMS:

ü  define Terms of Reference of study

ü  shortlist two or three products

ü  evaluate products

ü  recommend selection and produce report

   VI.            Application design:

§  Design of user interface and application programs that use and process the database.

§  Database design and application design are parallel activities.

§  Includes two important activities;

ü  transaction design

ü  user interface design

 VII.            Prototyping :

§  Building working model of a database system.

§  Purpose

ü  to identify features of a system that work well, or are inadequate

ü  to suggest improvements or even new features

ü  to clarify the users’ requirements

ü  to evaluate feasibility of a particular system design

VIII.            Implementation:

§  Physical realization of the database and application designs.

ü  Use DDL to create database schemas and empty database files.

ü  Use DDL to create any specified user views.

ü  Use 3GL or 4GL to create the application programs. This will include the database transactions implemented using the DML, possibly embedded in a host programming language.

    IX.            Data conversion and loading:

§  Transferring any existing data into new database and converting any existing applications to run on new database.

§  Only required when new database system is replacing an old system.

ü  DBMS normally has utility that loads existing files into new database.

§  May be possible to convert and use application programs from old system for use by new system.

      X.            Testing:

§  Process of running the database system with intent of finding errors.

§  Use carefully planned test strategies and realistic data.

§  Testing cannot show absence of faults; it can show only that software faults are present.

§  Demonstrates the database and application programs appear to be working according to requirements.

§  Should also test usability of system.

§  Evaluation conducted against a usability specification.

    XI.            Operational maintenance:

§  Process of monitoring and maintaining database system following installation.

§  Monitoring performance of system.

ü  if performance falls, may require tuning or reorganization of the database.

§  Maintaining and upgrading database application (when required).

§  Incorporating new requirements into database application.

https://apps.bsu.edu

03.   Explain the importance of database design stage?

Database design is important because a database should be catered to fit the needs of the company or business using the database. Not all databases can function the same way, especially because not all businesses function in the same way. Additionally, a database needs to be user friendly. It needs to provide users with a means of getting to and storing their information with little trouble. It also needs to be secure against outside attacks.

http://www.inf.udec.cl/

04.   What are the phases using database design stage?

        I.            Conceptual database design  :

§  Process of constructing a model of the data used in an enterprise, independent of all    

       physical considerations.

          

§  Data model is built using the information in users’ requirements specification.

§  Conceptual data model is source of information for logical design phase.

ü  ERD, DD

      II.            Logical database design  :

     

§  Process of constructing a model of the data used in an enterprise based on a specific data model

 (E.g. relational), but independent of a particular DBMS and other physical      considerations.

§  Conceptual data model is refined and mapped on to a logical data model.

ü  DB schemas

    III.            Physical database design :

§  Process of producing a description of the database implementation on secondary storage.

§  Describes base relations, file organizations, and indexes used to achieve efficient access to data. Also describes any associated integrity constraints and security measures.

§  Tailored to a specific DBMS system.

05.   Explain usage of ER diagrams and why it is so important for database development?

Developing a database without an ERD as building a house without a building plan. It might be doable because you think that simply laying a brick one over another is enough to build something; however the moment somebody else takes responsibility over the project there is disaster potential. In my experience you will not benefit much from ERDs unless you use them in conjunction with CASE tools (Erwin, MySQL Workbench etc.) which will additionally allow you to perform some really helpful operations such as forward and reverse engineering. Even without these functions having a centralized schematic of the complete database is useful because sometimes the constraints implemented in the database itself are not enough to tell the full story about the relationships between particular database entities. Here is an example involving MySQL which, as you might know, implements several internal storage engines, most notably MyISAM and InnoDB. There are significant differences between them one of the most important one being that MyISAM doesn't support constraints. Despite that fact MyISAM is heavily used for web applications which means that the relational logic needs to be implemented either through business logic (application code)

or in another way. The problem is when you forward engineer an ERD with MyISAM tables

(Entities) MySQL will silently ignore the constraints set by the ERD and you will end up with

a database which doesn't clearly identify the nature of the relationships between entities. In

other words after you develop the database layout there is no way for the code developers

to implement proper business logic without an ERD.

ER Diagrams Important:

§  If you want to use a DBMS, you need to be able to represent your data in it.

§  There are many ways to achieve this.

§  We will discuss one approach that is traditionally seen as a good and successful one.

§  No matter which approach is used, one can end up with a good or a bad database design.

§  In a future lecture, we will discuss objective criteria for discovering and fixing bad design choices.