Database management systems

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Database management systems

Q#1)What are the advantages and disadvantages of implementing distributed and centralized databases? Does the size and location of the organization dictate if the database is centralized or distributed? Why?

Distributed database is a collection of data which are connected in a system through a simple logical network. They are managed through a distributed database management system in a single network. In the system, each part has its own dat6abse and an operating system. On the other Hand, a centralized database management has all the data stored in a single place fined as collection of logically distributed database which are connected with each other through a network.

The advantages of a centralized database are that all the data can be mined from the same network, this enhance the efficiency of the system and data recovery. This is also advantageous as the systems can be maintained from a central place in well contained manner. Centralized database is limited to those at central place, any downtime in the system leads to lose as the system is completely locked down

The distributed database is advantageous because the data can be accesses by geographically distributed clients without slowing down the system. This system is also advantageous because of the location transparency (Korth, & Silberschatz, 1998).

The size and location of the organization does not determine if the database is distributed because distribution of the database depends on the storage facilities and the computers in use. In a distributed system the remote databases have their own local autonomies over their data as they can take responsibility for the security of the data, the backup and recovery. They also control the concurrency of the database as well.

Q#2) what are some of the important considerations regarding DBMS/Database design? Explain why these considerations are important.

1) Security – DBMS is a very important part of any setting that takes care of the data stored in the database, security of the system should be given the highest priority. This does NOT only apply to the data in the data base but also to the [possible breaches. Therefore security of the dbms also concerns the hardware, software, people, and data. THIS requires the implementation of a superior mission objectives for the whole debase management systems. This increasing interest in the security of then database is as results of the reliance on the computer for the storage of data. The main concepts in ensuring the security of a DBMS include authorization, Views, backup and recovery, integrity, encryption and RAID (Elmasri, &Navathe, 2004).

2) Transaction rate: the kind of traffics to the data base. A debase is supposed to be scalable to allow for future un-predetermined database accesses. This will ensure that the number of systems downtimes is reduced and the throughput is increased thereby enabling the organization to realize their database design objectives. The designer should know whether the system is read only or both. Determination of the usage patterns also helps in determining if the system can work at peak times or even if the usage patterns are evenly distributed

3) The nature of the uptime- uptimes is also another important factor to consider as it determines the number of downtimes s set is supposed to register to [prepare for the possibilities of failures. The uptimes range from the normal 16×5 and the 24×7. But it is imperative to know that the 24×7 does not allow for downtimes when then systems can be maintained

4) The nature of database administration- according to Elmasri, &Navathe, (2004), it is important to consider the way the database will be administered, as it helps in reducing the number of system downtimes when administering the database. If the administration is to be carried every day at a central point or if the administrations to be carried at different remote points. DB administration may include backups, transfers to other systems, systems integrations, data loading etc are much more important to consider especially if the database is used for commercial purposes (Korth, &Silberschatz, 1998).

Q#3) Does MS Access support all nine DBMS functions identified listed in chapter service? Why or Why not? Describe how MS Access implements these functions.

Teorey, Lightsome &, Nadeau, (2006), states that the main functions of database management systems are: indexing, Views, Security, Integrity, Concurrency, Backup/Recovery, Design, Documentation and Update/Query. Ms Access can support a number of this function, but cannot support some functions due to incompatibility between the systems. For example, access has a number of query performance problems based on the resource mamanement systems used in the latest version of the databases. This was dues to the incompatibility and causes delays in returning the delays. However, Ms Access uses the hot fixes KB2553029 to speed up the query performance. On the other hand, ms access does not function in a number of operating systems like the Mac Os, Linux, BSD, and Amiga etc. this is due to the configuration systems used in the systems (Raghu, & Gehrke, 2000).

There are a number of functionalities such as connectivity and interactions that the ms access does not support. The ms access is a native PHP; it is therefore not easy for their connectivity to offer high indexing functionality and query / update. Ms can only achieve this by using the open database management system for direct access. Then reason form thins is that ms Access is a low end natively DBMS with a poor middle-tier PHP script. Ms can also reverse engineer the script to work sufficiently.

Ms Access has a limited support for the storage functionality. This is achieved but importing database for Ms Access jet 4. By conecting ms access to live databases through the ODBC, one can easily imports the database schemas into any standard UML model. This also enhances the level of synchronization between the data models and the live databases (Teorey, Lightsome, & Nadeau, 2006).

References

Elmasri, R. Navathe, S. (2004). Fundamentals of Database Systems. 4th ed., Pearson Addison Wesley,

Korth, H.; Silberschatz. (1998). Database Systems. Third Edition. Makron Books.

Raghu R., & J. Gehrke., (2000). Database Management Systems, Second Edition, McGraw-Hill,

Teorey, T.J., Lighstone S., Nadeau, (2006). Database Modeling and Design, 4th. ed., Morgan Kaufmann Publishers, Inc, San Francisco