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What is JDBC or Java Database Connectivity?

March 4th, 2009 by Shenron

Java Database Connectivity is basically a framework that supports the programs in order to access files from databases, flat files and spreadsheets. The Java database connectivity works by making connections with the user program and transforming into a “backstage” access to the database, regardless of the type of database management system used. Moreover, Java Database Connectivity is an application program interface for Java programs that allows users to gain access on pertinent data by the use of queries. With the use of the Java Database Connectivity, the user will have the opportunity to update significant information within the database.

Java Duke - Butler

Java Database Connectivity is significantly a part of the Java Program. This tool is primarily used to allow multiple procedures and continue to allow these procedures to be used by the same application. With the help of the drive manager, the Java Database Connectivity will be established correctly.

How to Use the Java Database Connectivity Driver

Connecting to a database or platform will be easy with the use of the Java Database Connectivity (JDBC). Regardless of the type of database and platform, you can effectively use the Java Database Connectivity. All you need to do is assess the capacity of your database and choose the most appropriate platform you’re going to use. You can choose either oracle, Informix, Microsoft, MySQL and other platforms available in the market. Installed in these platforms are the JDBC drivers that you can use to connect and manipulate the items in the database. You can download the JDBC driver that comes with the database platform. The JDBC driver will come with instruction that you should follow specifically. Make sure that the installation is well in place, so you can activate your drive manager to gain access to the database even in a Java program.

How to Connect to the Database Using the JDBC

To gain access to your database, you need to retrieve an object of the “connection” class from your driver manager. You’ll definitely need a URL and parameters for the database and access controls respectively. These controls usually include the username or authentication as well as the password. An example of a URL in a java database – jdbc: mysql://db_server:3315/contacts/. Although a Java URL seems different than a normal URL, they’re actually the same. They have the same protocol, machine number and host name. If security is not an issue, you can probably access to databases easily. All you need to have is the authentication name, password and a database account.

In using the Java Database connection, you need to learn how to manipulate certain files. You need to learn how to structure the elements and develop query statements. Keep in mind that when you’re using the SQL statements, you can use the INSERT, DELETE and UPDATE commands, but in Java Database Connections, you should remember that they’re represented by a statement (delivered to the database every time), prepared statement (predetermined and is allowed to be executed several times) and callable statements (executes stored procedures).

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Posted in General, SQL | | 2 Comments

What is ODBC or Open Data Base Connectivity?

March 4th, 2009 by Shenron

ODBC is the short term used for Open Database Connectivity. It is the interface used by programmers to be able to use databases using SQL queries. ODBC is also defined as another method of accessing information that is stored in your computers or even in your office. You can use ODBC to access the databases from Microsoft Access, Excel and dBase. In the perspective of the end-user, ODBC is the best way of accessing information stored in another database without the need of understanding how it is done. In the perspective of the programmer, ODBC is a code that can make programming easy enough so it can access other databases in other software.

ODBC Screens

The creators of ODBC, which is Microsoft and Simba Technologies, aim to make ODBC stand on its own. This simply means that the ODBC software doesn’t need other programming languages for it to function. Microsoft and Simba Technologies released ODBC in September 1992 and since then has become a part of the standard SQL that is internationally accepted. Since ODBC is now becoming accepted internationally, programmers are now making software that is ODBC compliant. This way, getting information from other databases using ODBC will be easy. Operating systems are now using ODBC such as UNIX and Apple.

Advantages of ODBC

The ODBC was created to be an interface that can access different kinds of databases by converting its codes into something that it can understand. This capability of ODBC has helped people access their databases without learning other programming languages. The advantage of using ODBC is that multiple applications can be opened not only to access the databases but also to manipulate or update them at the person’s leisure. The capability of the ODBC to recode the SQL is the reason behind its ability to access different databases. There is a setback to the ODBC. The rising number of ODBC clients uses up drivers and DLLs may lead to a system overload. Though this is only a small setback, the use of ODBC technology such as the Multi-tier ODBC server allows it to be addressed and lessen the problem. The development of newer drivers today is being questioned with its capability of handling ODBC. Since ODBC was created in the early 90s, it has a wider capability than the ones today. New drivers may still hold bugs which are now being remedied by programmers.

Using ODBC

Using ODBC requires three components, and these are the following – ODBC drivers, ODBC client and the DBMS or Database Management System Server. Examples of the DBMS servers are Microsoft Access, Excel, and Oracle. The process of ODBC starts with the ODBC client who will give a command for it to work together with the database server, but before the DBMS server receives the command, the ODBC driver will then transcribe the command to the code which the DBMS server can understand. This is how the ODBC works. The server will then give its reply back to the ODBC driver before it can reach the ODBC client.

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Posted in General, SQL | | 1 Comments

What is SQL or Structured Query Language?

March 4th, 2009 by Shenron

A structured query language or SQL is a database language used to retrieve information from a database management system. The SQL is considered as the standardized language for programming, extracting and managing files from the database. The SQL is standardized by both the American National Standardized Institute (ANSI) and the International Organization for Standardization (ISO). This means that many databases support the SQL. SQL allows users to extract, edit, supplement and remove data from the database. Moreover, the SQL has a call level interface, which allows the user to use the database remotely and have access to the data on the database separately. With the use of an SQL, authorized users can also manage and monitor your database.

SQL Database

The Purpose of Structured Query Language (SQL)

The primary purpose of a SQL is to query data in a database system. The SQL is a declarative language, which allows sets of functionality such as retrieving and deleting data from the database. However, SQL also has extensions which add to the language programming of databases. These extensions include SQL/PSM or the Structured Query Language and Persistent Storing Module, the procedural SQL, and the transact SQL.

How to Use the SQL?

The SQL is primarily used for querying. The most common operation in SQL databases includes the keyword “SELECT”. The keyword “SELECT” extracts data from a specific table in a database. Unlike any keywords used in SQL, the “SELECT” keyword does not have any significant effect on the data in the database. The use of queries in an SQL database is significant to the users because it allows the user to plan and manage the files in the database.

SQL can also be used in manipulating the data. With the use of the SQL, the user can insert, update and remove data from the database. When you use the keyword “INSERT”, you add data in a particular table. If you’re going to use the keyword “UPDATE”, you modify the values set in a table. If you use the keyword “DELETE”, this means that you remove zero or any data on the existing table. The keyword “MERGE”, on the other hand, is the combination of the command “INSERT” and “UPDATE”.

SQL is also used in transaction controls. If you’re going to use the command “COMMIT”, this will cause the data installed in the database to become permanent. On the other hand, if you’re going to use the command “ROLLBACK”, the data will return back to its original state prior to the last “COMMIT” or “ROLLBACK” command. Moreover, users can utilize the SQL in data definition, which allows users to create new tables, and data control.

The Drawbacks of Using SQL

Although SQL is the main component of making databases, this operational language has its drawbacks. The SQL is quite complicated to some users. The queries or languages used are sometimes hard to decipher and often difficult to construct. Moreover, SQL is not compatible with some vendors. That’s why SQL should be applied to compatible softwares only so users can maximize the potentials of this tool.

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Posted in SQL | | 2 Comments

What is High Availability?

March 4th, 2009 by Shenron

In IT terms, high availability is the term used to describe a server or network, and by extension all of the constituent components, that is continuously available for data input, processing, and report querying. In it’s simplest sense, we see high availability in our everyday interactions on the web, it is very rare for the top 10 websites to be offline.

The systems and protocols in place largely determine the success or not of a high availability goal, mostly because components fail randomly, and no group of components is ever going to be failsafe, so ensuring continuous supply of service is dependent on planning and understanding the tolerances that affect the network.

Datacenter

Twenty-first century society is so dependent on computers and their processing power that anything less reliable and permanent uptime is considered a failing, corporations thrive or fail on their network or service uptime reputation.

Even at the small corporation and private individual level, high availability may still be necessary and desirable. Our dependence on timely email, online banking and financial trades, upto date weather and news, are all examples of services that require high availability, failing to deliver only ever benefits the competition in a free market.

Fault tolerance is an important measure of any high availability system or network, essentially a single failure point should never bring the entire system down, an alternate component should be able to transparently take over the task until the original is replaced or repaired.

Reliable components with long lives and capable of sustaining extensive periods without maintenance also form an important aspect of high availability networks. Typically these components are not the cheapest models in the market, increased reliability is a factor of how well designed and made a component is, and higher quality standards come with a price.

Measuring reliability is often considered in terms of an uptime percentage, certainly most telecommunications and web hosting corporations advertise uptime guarantees of 99 or higher percent. Mission critical availability of servers, and networking systems is often described in terms of 99.999% uptime, equating to just 5.26 minutes of downtime per month.

In fact, this measure is not easily quantified and is subject to interpretation, a server that is up may not be available to the end user, for example when an outage occurs on some other part of the network, or where a software glitch prevents the user from completing their task.

Creating a high availability system will involve extensive planning, with the goal being to make the entire system as simple as possible, with the least number of potential failure points. Overly complex systems typically have more failure points that need to be accounted for, increasing cost, complexity, and monitoring. By contrast simpler systems are easier to monitor, and despite using more expensive and more reliable components are often cheaper to build in the long run.

Testing high availability networks at their failure points should be conducted regularly, however backup systems or redundant components also require testing, thus ensuring the entire network remains available in the event of component failure or disaster.

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What is Data Integration?

March 4th, 2009 by Shenron

Data integration involves taking data from two or more databases, sometimes within the same company, and producing meaningful reports from the merged data. Data integration can be thought of as one of the holy grails of IT, and at the same time a major headache for most IT professionals.

The vast majority of databases used in corporations are proprietary in nature, designed by the supplier to suit the needs of their querying software, not for integration with other data systems, leading to difficulties creating a report that combines two sets of data, for example sales data from a spreadsheet or customer relationship database, with banking reconciliation data from the accounts software.

Blue Digital Globe on top of binary code

On the face of things the example above sounds simple enough that manually comparing the two disparate reports would give the complete picture, but the example is too simplistic, there could be many other reports that are too complicated for a quick scan of the separate results, and this is where data integration becomes the solution.

IT specialists with database programming skills are required, who write specific applications that allow for querying multiple source data sets, often this will be a patch to existing software, but in many cases could be a completely separate piece of software tailor written for the end user.

More often these days IT departments are requiring compatibility between databases before implementing new software across the corporation, adding to the license expenses and requiring a long term commitment to maintaining the custom software thru version changes for all the source databases.

In the online world data integration is being driven by the open source community who have developed OpenID allowing members of social networks to login to many proprietary networks using a single login and password, and carry their personal data to that new network.

Computer software that does use data integration to produce new and unique reports from two or more databases are the type used in keyword analysis in the search engine optimization market where specialist software or websites query databases from the major online advertising agencies.

The corporate world is no different, some of the biggest Fortune 500 companies were created thru mergers and acquisitions of companies using different software and databases, and data integration is essential to producing accurate and reliable financial reports.

One of the most popular methods of making date integration happen with large databases is to create a new database from running queries on the original databases, and then writing specialist front-end software for the new database which queries only the new database to produce the reports needed.

This technique is known as data warehousing and can be a simpler and more cost effective approach because regular exports from the original database can be scheduled, and then imported into the warehouse. With proprietary software this approach reduces licensing issues and possible corruption of databases.

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Posted in Data Integration | | 4 Comments

What is Disaster Recovery?

March 4th, 2009 by Shenron

Disasters happen, be they manmade or natural, no corporation or government can ever assume their data and access to their data will be exempt from damage. Disaster recovery is their ability to recover electronic data and data processing to pre-disaster levels in the shortest possible time thru forward planning and setting policy objectives.

Preparing for disasters and knowing that recovery will be possible requires careful analysis of the threats facing a corporation such as earthquakes, terrorism, hacking, staff strikes, electrical failure, even human error, and understanding the consequences for data of each possible situation.

Disaster Recovery

The simple activity of keeping off-site data backups may be all that is required for recovery in smaller corporations and private households, but in larger corporations most responsible IT managers would consider this a basic minimum which would already be provisioned and costed as part of their annual budgets.

Some disasters on the other hand have very little to do with recovering backups, a denial of service attack (DoS) on the corporate website could happen at any time, and all the backups in the world won’t help the corporation with their recovery, instead skilled manpower is needed. This is the sort of disaster that affects a corporation’s ability to use it’s data and communicate with stakeholders, and if not contained quickly affects credibility and stockholder confidence.

Forward planning for eventualities such as DoS attacks and other forms of hacking or viruses often involves contracting third parties for network routing and emergency response. Common network related disasters include hacking, viruses, server and router failure, cable fractures or satellite failure, or any number of other failures in the network loop.

Protecting a corporation from disasters is costly, and often considered a wasted expense until after a major disaster has occurred, and business recovery specialists often complain of the difficulties they face convincing management and staff of the need to work to set procedures.

Equipment and network redundancy plays a large role in mission critical disaster recovery, and may in extreme situations require two or three completely separate systems performing the same task. Many Fortune 500 corporations may not need completely redundant systems that can be brought online almost instantly although this is common in larger financial corporations, and of course large telecommunications operators.

The construction of disaster proof data centers with high levels of redundancy, fire containment, and temporary power generation is often seen as integral to disaster recovery planning, as well as provision of redundant network loops to third parties. Most major corporations and governments allocate as much as 5% of their annual IT budget to disaster recovery planning, a high expense, yet preferable to not continuing in business in the event of catastrophic data loss.

Preparing for every possible contingency would require superhuman effort and unlimited funds however using the Pareto Principle (80-20 rule) and planning in advance for the few disasters that could permanently shut down the corporation is much more affordable, and once these steps are in place the incremental cost of adding more preparedness may not cost that much more.

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What is a DBA or Database Administrator?

March 3rd, 2009 by Shenron

Briefly, a database is your collection or data stored in your computer. It is your organized filing system on your computer system which helps you keep track of everything and manages all your information or documents in a way that will be easy to access and manipulate every time.

Your database management system dictates just how effective or ineffective the system actually is, and it will likewise determine whether your data storage program is working for you or against you.

In order to come up with an efficient data storage system on your computer system, especially if you want the same data accessible to several computers, you will need the expertise of someone who knows how to work databases, and that is your database administrator or manager.

Database Administrator

Database Administrator Job Description

The job description of a database administrator is a long list of installing, designing, maintaining and updating the database management system you have in place. This means that they have to be always in the know about the latest upgrades in software or programs that your database system is using to make your database management system at par with the rest of the IT world.

A good database administrator should know all the workings of your database system so that, when incidents of errors occur, they can easily retrieve lost data, correct the errors, and basically put everything back to normal before the SNAFU happened.

If you are looking at creating an efficient database management system for a network of users in an office setup, you probably also have a system administrator who takes care of the networking aspect of your computer system.

If this is the case, your system manager and your database manager should work hand in hand to incorporate the database software into the network system. Therefore, a good database manager should also know how to work with a system administrator to optimize your database software or program.

A Good Database System

In a word, a good database system works to your advantage. If it has more foul-ups than you’d care to know, it’s probably high time to either change your database design or change your database manager.

A good database management system as designed and implemented by your database manager allows you to work efficiently with as little effort as possible. This means that the program is performing at the highest possible rate so you won’t experience downtimes and with as little possibility for errors as possible.

While it is very important that your database manager should be able to protect all your data to the point of restoring the program to its original form should foul-ups occur, they should also be able to provide you with the proper security to ensure that your data is safe within the network, and a sound security in place ensures that your confidential data are not open to anyone trying to access them, especially those without the authority to do so. Simply put, your database administrator can make life easier for the entire office if they know what they’re doing.

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IBM DB2 Database

March 3rd, 2009 by Shenron

DB2 or database 2 is basically related to the relational database management system (RDBMS), which is part of the databases created by the IBM group. DB2 works by developing an access to a wide variety of databases or providing an open database environment for several computing platforms. In short, the DB2 database can make a significant change in the database management system. The DB2 database can create a single-user application and transform it to a multi-user system. Moreover, the DB2 database can be run using the SQL and it also include technical and management tools. With the use of the SQL, users can retrieve data from one database to the other at the same time.

IBM DB2 Database ibm db2

History of the IBM DB2 Database

The IBM DB2 database runs a long history. It has been considered as one of the first databases ever developed that uses the SQL (which was also developed by IBM). DB2 was first used as part of IBM’s MVS mainframe platform in 1983. But DB2 has its roots back in the early seventies. The DB2 was developed by Dr. Codd. In 1970, Dr. Codd has established the theory on data manipulation. He later on devised a model that would perfectly work for relational databases. He called this model, “Alpha”. The theory of Codd was not recognized by the IBM group and thus leaves the revisions to a set of programmers who happen to be violating some of the rules governing Codd’s model. The output was called Structured English Query Language or SEQUEL. When IBM’s first relational database model was released, they changed the name of the language to SQL.

For many years, IBM DB2 database has been commercialized and distributed to other database developing companies. In order to avoid paying unnecessary database features, IBM created different editions of the DB2.

All about IBM DB2 Database and Its Features

IBM DB2 database works in two ways. You can either use a command line or a GUI. A command line requires ample knowledge of the product but keep in mind that the product is automated as well as scripted. GUI, on the other hand, is a product of Java, which is a multi-platform for beginners. DB2 also uses the SQL and the XQuery. SQL or the Structured Query Language is the primary language used by the IBM DB2 database. If you’re going to use the XQuery, you’ll need to understand how the store XML data. You should store the XML data as XML and not as CLOB data to have a faster access of the XQuery.

IBM DB2 is written in C, C++, Java, Ruby, FORTRAN and other programming languages. Aside from these features, IBM DB2 database also has a very important feature and that is error processing. Primarily, the SQL communications area is included in the DB2 program, which works by returning the error of the application programs after the execution of SQL statements. If you’re going to use the DB2 database, you must remember the DB2 return codes, which include:

Zero “0″ means a successful execution.

A positive number, “+50″, means that the execution was successful and there are one or more warnings.

A negative number, “-50″, means that the execution was unsuccessful and there are significant errors.

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