Type of database

 Type of database

    The following types of database are explained here.

        1. Transactional Databnase

        2. Decision Support Databases

        3.  Hybrid Source Databases.

  1. Transctional Databases

        A transctional database is a DBMS that supports the rollback of transactions (undo of transcations) on the 

database if not completed properly. Incompletion may occur due to power failure or an interruption in connectivity

to the database. Majority of databases in use today support transctions.

    Transction Operations are

    1   Commit  -   make the changes  made by the transcation permanent to the database.

    2.  Rollback  - undo the transcations that have not been committed to the database.

        Transcational database Opreations follow the given pattern

    1)  Initiate the transcation

     2) Execute the given queries or manipulations.

     3) Commit the transcation and complete if there are no errors.

      4) if an error occurs in the transcation roll it back and end the operation.

        Advantages

        1 Flexibility

          2 improved ability to retrive history

            3. minimal risk of losing data due to power failure.

         Disadvantages

1)   Less opportunity  to changes information within a transactionbal database.

2)    Less readable data.

Example:   Oracle, MySQL, etc

2) Decision Support Databases

        Decision support database contain data form various sources. the sources may be

internal data form the organization

The data generated by different application

External data mined form the internal, etc.

The decision support database can etc.

a small database

a standalone system or 

a huge data warehouse

To avoid the interference of decision support system with the working of operational system, the decision

support database usually contains a copy of the production database.

DSS(Decision Support system) software system analyzes the data and produces the required information.

   DSS user interfacer is an interactive graphical interface which makes the interaction easier between the DSS and its users. it displays the results of the analysis.

3 Hybrid Databases

    A hybrid  database is a database is a database system that supports and uses both on -disk and in-memory 

data storege. The system makes use of  hard disks for saving and retaining data and also makes use of memory for data that is in dynamic use.

Hybrid database is a combination of two or more database types.

Example: Hybrid XML/Relational Databases.

This can store and retrieve both XML data and relational data.

A hybrid database model is shown in fig.

Here the application can access both XML data and relational data using SQL and XQuery query language. The hybrid data is stored in hybrid XML/relational database management server.

The storage representation of hybrid DBMS is shown in figure.

                                    Hybrid DBMS

            Memory data                        Buffer  Disk data

Benefits

1. Performance

    Sorting, storing and retrieving data form memory rather than disks makes all processes quiker.

2. Cost

      Hard disks Cost  less then memory. So some of the money saved can be used to add more memory to improve performance.

3. Persistance

    Even though, memory is used for data storage, disk are still used to store data needed for later use. this ensures that the data are not lost during power failure.

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